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根据设计思想和实现步骤，采用程序设计语言描述算法（使用C、C++或Java语言实现），关键之处请\n给出简要注释。","options":[],"hasFigure":false,"source":"curated"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":8,"stem":"（\n8分）某计算机的CPU主频为500MHz，CPI为5（即执行每条指令平均需5个时钟周期）。假定某外设\ndata link\n\n的数据传输率为0.5M B/s，采用中断方式与主机进行数据传送，以32位为传输单位，对应的中断服务程序\n包含18条指令，中断服务的其他开销相当于2条指令的执行时间。请回答下列问题，要求给出计算过程。\n1） 在中断方式下，CPU用于该外设I/ O的时间占整个CPU时间的百分比是多少？\n2） 当该外设的数据传输率达到5M B/s时，改用DMA方式传送数据。假定每次DMA传送块大小为\n5000B，且DMA预处理和后处理的总开销为500个时钟周期，则CPU用于该外设I/ O的时间占整个CPU\n时间的百分比是多少？（假设DMA与CPU之间没有访存冲突）","options":[],"hasFigure":false,"source":"curated"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"（13分）某计算机字长16位，采用16位定长指令字结构，部分数据通路结构如下图所示，图中所有控制\n信号为1时表示有效、为0时表示无效。例如控制信号MDRin E为1表示允许数据从DB打入M DR，M DRin\n为1表示允许数据从内总线打入MDR。假设MA R的输出一直处于使能状态。加法指令“ADD (R1)，R0”\n的\n功能为(R0)+((R1))\n\n(R1)，即将R0中的数据与R1的内容所指主存单元的数据相加，并将结果送入R1\n的内容所指主存单元中保存。\n下表给出了上述指令取指和译码阶段每个节拍(时钟周期)的功能和有效控制信号，请按表中描述方式用表格\n．．\n列出指令执行阶段\n．．．．．．\n每个节拍的功能和有效控制信号。","options":[],"hasFigure":true,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":7,"stem":"（7分）三个进程P1、P2、P3互斥使用一个包含N(N>0)个单元的缓冲区。P1每次用produce()生成一个正\n整数并用put()送入缓冲区某一空单元中；P2每次用getodd()从该缓冲区中取出一个奇数并用countodd()统\n计奇数个数；P3每次用geteven()从该缓冲区中取出一个偶数并用counteven()统计偶数个数。请用信号量机\n制实现这三个进程的同步与互斥活动，并说明所定义信号量的含义。要求用伪代码描述。","options":[],"hasFigure":false,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"（8分）请求分页管理系统中，假设某进程的页表内容如下表所示：\n时钟 功能 有效控制信号\nC1\nMAR\n\n(PC)\nPCout, MARin\nC2\nMDR\n\nM (MDR)\nPC\n\n(PC)+1\nM emR, M DRinE, PC+1\nC3\nIR\n\n(MDR)\nMDRout, IRin\nC4\n指令译码 无\n页号 页框(Page Fra me )号 有效位(存在位)\n\n页面大小为4KB，一次内存的访问时间是100ns，一次快表(T LB)的访问时间是10ns，处理一次缺页的平均\n时间10\n8\nns(已含更新T LB和页表的时间)，进程的驻留集大小固定为2，采用最近最少使用置换算法(LRU)和局\n部淘汰策略。假设①T LB初始为空；②地址转换时先访问T LB，若T LB未命中，再访问页表(忽略访问页表之\n后的T LB更新时间)；③有效位为0表示页面不在内存，产生缺页中断，缺页中断处理后，返回到产生缺页中\n断的指令处重新执行。设有虚地址访问序列2362H、1565H、25A 5H，\n请问：\n(1) 依次访问上述三个虚地址，各需多少时间？给出计算过程。\n(2) 基于上述访问序列，虚地址1565H的物理地址是多少？请说明理由。","options":[],"hasFigure":true,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":9,"stem":"（9分）某网络拓扑如下图所示，路由器R1通过接口E1、E2分别连接局域网1、局域网2，通过接口L0\n连接路由器R2，并通过路由器R2连接域名服务器与互联网。R1的L0接口的IP地址是202.118.2.1；R2\n的L0接口的IP地址是202.118.2.2，L1接口的IP地址是130.11.120.1，E0接口的IP地址是202.118.3.1；\n域名服务器的IP地址是202.118.3.2。\nR1和R2的路由表结构为：\n目的网络IP地址 子网掩码 下一跳IP地址 接口\n(1) 将IP地址空间202.118.1.0/24划分为2个子网，分别分配给局域网1、局域网2，每个局域网需分配的\nIP地址数不少于120个。请给出子网划分结果，说明理由或给出必要的计算过程。\n(2) 请给出R1的路由表，使其明确包括到局域网1的路由、局域网2的路由、域名服务器的主机路由和互\n联网的路由。\n(3) 请采用路由聚合技术，给出R2到局域网1和局域网2的路由。\n0 101H 1\n1 —— 0\n2 254H 1","options":[],"hasFigure":true,"source":"curated"}]},{"year":2010,"title":"2010年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若元素a、b、c、d、e、f依次进栈，允许进栈、退栈操作交替进行，但不允许连续三次进行退栈操作，则\n不\n．\n可能得到的出栈序列是______。","options":[{"key":"A","text":"d c e b f a"},{"key":"B","text":"c b d a e f"},{"key":"C","text":"b c a e f d"},{"key":"D","text":"a f e d c b"}],"hasFigure":false,"source":"curated"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"某队列允许在其两端进行入队操作，但仅允许在一端进行出队操作。若元素a、b、c、d、e依次入此队列\n后再进行出队操作，则不\n．\n可能得到的出队序列是______。","options":[{"key":"A","text":"b a c d e"},{"key":"B","text":"d b a c e"},{"key":"C","text":"d b c a e"},{"key":"D","text":"e c b a d"}],"hasFigure":false,"source":"curated"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列线索二叉树中（用虚线表示线索），符合后序线索树定义的是______。","options":[{"key":"A","text":""},{"key":"B","text":""},{"key":"C","text":""},{"key":"D","text":""}],"hasFigure":false,"source":"curated"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"在右图所示的平衡二叉树中，插入关键字48后得到一棵新平衡二叉树。在新平\n衡二叉树中，关键字37所在结点的左、右子结点中保存的关键字分别是______。","options":[{"key":"A","text":"13，48"},{"key":"B","text":"24，48"},{"key":"C","text":"24，53"},{"key":"D","text":"24，90"}],"hasFigure":true,"source":"curated"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"在一棵度为4的树T中，若有20个度为4的结点，10个度为3的结点，1个度\n为2的结点，10个度为1的结点，则树T的叶结点个数是______。","options":[{"key":"A","text":"41"},{"key":"B","text":"82"},{"key":"C","text":"113"},{"key":"D","text":"122"}],"hasFigure":false,"source":"curated"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对n（n≥2）个权值均不相同的字符构造成哈夫曼树。下列关于该 哈夫曼 树的叙述中，错误\n．．\n的是______。","options":[{"key":"A","text":"该树一定是一棵完全二叉树。"},{"key":"B","text":"树中一定没有度为1的结点。"},{"key":"C","text":"树中两个权值最小的结点一定是兄弟结点。"},{"key":"D","text":"树中任一非叶结点的权值一定不小于下一层任一结点的权值。"}],"hasFigure":false,"source":"curated"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若无向图G=（V, E）中含 有7个顶点，要保证图G在任何情况下都是连通的，则需要的边数最少是_____。","options":[{"key":"A","text":"6"},{"key":"B","text":"15"},{"key":"C","text":"16"},{"key":"D","text":"21"}],"hasFigure":true,"source":"curated"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对右图进行拓扑排序，可以得到不同的拓扑序列的个数是_____。","options":[{"key":"A","text":"4"},{"key":"B","text":"3"},{"key":"C","text":"2"},{"key":"D","text":"1"}],"hasFigure":true,"source":"curated"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知一个长度为16的顺序表L，其元素按关键字有序排列。若采用折半查\n找法查找一个L中不存在的元素，则关键字的比较次数最多的是_____。","options":[{"key":"A","text":"4"},{"key":"B","text":"5"},{"key":"C","text":"6"},{"key":"D","text":"7"}],"hasFigure":false,"source":"curated"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"采用递归方式对顺序表进行快速排序。下列关于递归次数的叙述中，正确的是______。","options":[{"key":"A","text":"递归次数与初始数据的排列次序无关。\na\nb c\nd\nNull\na\nb c\nd\nNull Null\na\nb c\nd\nNull\na\nb c\nd\nNull\ne\nd\na\nb c\n24\n13\n53\n37 90"},{"key":"B","text":"每次划分后，先处理较长的分区可以减少递归次数。"},{"key":"C","text":"每次划分后，先处理较短的分区可以减少递归次数。"},{"key":"D","text":"递归次数与每次划分后得到的分区的处理顺序无关。"}],"hasFigure":false,"source":"curated"},{"number":11,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"对一组数据(2，12，16，88，5，10)进行排序，若前三趟排序结果如下：\n第一趟排序结果：2，12，16，5，10，88\n第二趟排序结果：2，12，5，10，16，88\n第三趟排序结果：2，5，10，12，16，88\n则采用的排序方法可能是______。","options":[{"key":"A","text":"起泡排序"},{"key":"B","text":"希尔排序"},{"key":"C","text":"归并排序"},{"key":"D","text":"基数排序"}],"hasFigure":false,"source":"curated"},{"number":12,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列选项中，能缩短程序执行时间的措施是。\nI. 提高CPU时钟频率II. 优化数据通路结构\nIII. 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f","options":[{"key":"A","text":"仅I和II"},{"key":"B","text":"仅I和III"},{"key":"C","text":"仅II和III"},{"key":"D","text":"仅III和IV"}],"hasFigure":false,"source":"curated"},{"number":15,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"15．假定用若干个2k\nx4位的芯片组成一个8kx8位的存储器，则地址0B1FH所在芯片的最小地址是。","options":[{"key":"A","text":"0000H"},{"key":"B","text":"0600H"},{"key":"C","text":"0700H"},{"key":"D","text":"0800H"}],"hasFigure":false,"source":"curated"},{"number":16,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列有关RAM和ROM的叙述中，正确的是。\nI RAM是易失性存储器，ROM是非易失性存储器\nII RAM和ROM都采用随机存取方式进行信息访问\nIII RAM和ROM都可用作Cache\nIV RAM和ROM都需要进行刷新","options":[{"key":"A","text":"仅I和II"},{"key":"B","text":"仅II和III"},{"key":"C","text":"仅I,II和IV"},{"key":"D","text":"仅II，III和IV"}],"hasFigure":false,"source":"curated"},{"number":17,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列命中组合情况中，一次访存过程中不\n．\n可能发生的是。","options":[{"key":"A","text":"TLB未命中，Cache未命中，Page未命中"},{"key":"B","text":"T LB未命中，Cache命中，Page命中"},{"key":"C","text":"T LB命中，Cache未命中，Page命中"},{"key":"D","text":"T LB命中，Cache命中，Page未命中"}],"hasFigure":false,"source":"curated"},{"number":18,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列寄存器中，汇编语言程序员可见的是 。","options":[{"key":"A","text":"存储器地址寄存器(MA R)"},{"key":"B","text":"程序计数器(PC)"},{"key":"C","text":"存储 器数据寄存器(M 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->IV->V->VI->VII"},{"key":"D","text":"IV->I->V->VI->VII"}],"hasFigure":false,"source":"curated"},{"number":22,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"假定一台计算机的显示存储器用DRAM芯片实现，若要求显示分辨率为1600*1200，颜色深度为24位，\n帧频为85HZ，\n显存总带宽的50%用来刷新屏幕，则需要的显存总带宽至少约为______。","options":[{"key":"A","text":"245Mbps"},{"key":"B","text":"979Mbps"},{"key":"C","text":"1 958Mbps"},{"key":"D","text":"7 834Mbps"}],"hasFigure":false,"source":"curated"},{"number":23,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列选项中，操作系统提供给应用程序的接口是_____。","options":[{"key":"A","text":"系统调用"},{"key":"B","text":"中断"},{"key":"C","text":"库函数"},{"key":"D","text":"原语"}],"hasFigure":false,"source":"curated"},{"number":24,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列选项中，导致创建新进程的操作是______。\nI用户登录成功 II设备分配III启动程序执行","options":[{"key":"A","text":"仅I和II"},{"key":"B","text":"仅II和III"},{"key":"C","text":"仅I和III"},{"key":"D","text":"I、II和III"}],"hasFigure":false,"source":"curated"},{"number":25,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"设与某资源关联的信号量初值为3，当前值为1。若M表示该资源的可用个数，N表示等待该资源的进程\n数，则M、N分别是______。","options":[{"key":"A","text":"0、1"},{"key":"B","text":"1、0"},{"key":"C","text":"1、2"},{"key":"D","text":"2、0"}],"hasFigure":false,"source":"curated"},{"number":26,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列选项中，降低进程优先级的合理时机是_____。","options":[{"key":"A","text":"进程的时间片用完"},{"key":"B","text":"进程刚完成I/ O，进入就绪列队"},{"key":"C","text":"进程长期处于就绪列队中"},{"key":"D","text":"进程从就绪态转为运行态"}],"hasFigure":false,"source":"curated"},{"number":27,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"进程P0和P1的共享变量定义及其初值为\nboolean flag[2];\nint turn = 0;\nflag[0] = F","options":[{"key":"A","text":"LSE; flag[1] = FA LSE;\n若进程P0和P1访问临界资源的类C伪代码实现如下：\nvoid P1() // 进程P1\n{\nwhile(TRUE)\n{\nflag[1]=TRUE; turn=0;\nwhile(flag[0]&&(turn==0))\n;\n临界区;\nflag[1]=FALSE;\n}\n}\nvoid P0() // 进程P0\n{\nwhile(TRUE)\n{\nflag[0]=TRUE; turn=1;\nwhile(flag[1]&&(turn==1))\n;\n临界区;\nflag[0]=FALSE;\n}\n}\n\n则并发执行进程P0和P1时产生的情形是______。\nA. 不能保证进程互斥进入临界区，会出现“饥饿”现象"},{"key":"B","text":"不能保证进程互斥进入临界区，不会出现“饥饿”现象"},{"key":"C","text":"能保证进程互斥进入临界区，会出现“饥饿”现象"},{"key":"D","text":"能保证进程互斥进入临界区，不会出现“饥饿”现象"}],"hasFigure":false,"source":"curated"},{"number":28,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某基于动态分区存储管理的计算机，其主存容量为55M B(初始为空闲)，采用最佳适配(Best Fit)算法，分配\n和释放的顺序为：分配15MB，分配30MB，释放15MB，分配8MB，分配6MB，此时主存中最大空闲分\n区的大小是______。","options":[{"key":"A","text":"7M"},{"key":"B","text":"B．9M B"},{"key":"C","text":"10MB"},{"key":"D","text":"15M B"}],"hasFigure":false,"source":"curated"},{"number":29,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某计算机采用二级页表的分页存储管理方式，按字节编址，页大小为2\n10\n字节，页表项大小为2字节，逻辑\n地址结构为：\n页目录号 页号 页内偏移量\n逻辑地址空间大小为2\n16\n页，则表示整个逻辑地址空间的页目录表中包含表项的个数至少\n．．\n是______。","options":[{"key":"A","text":"64"},{"key":"B","text":"128"},{"key":"C","text":"256"},{"key":"D","text":"512"}],"hasFigure":false,"source":"curated"},{"number":30,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"设文件索引节点中有7个地址项，其中4个地址项是直接地址索引，2个地址项是一级间接地址索引，1\n个地址项是二级间接地址索引，每个地址项大小为4字节。若磁盘索引块和磁盘数据块大小均为256字节，\n则可表示的单个文件最大长度是______。","options":[{"key":"A","text":"33 K"},{"key":"B","text":"B．519 KB"},{"key":"C","text":"1 057 KB"},{"key":"D","text":"16 513 KB"}],"hasFigure":false,"source":"curated"},{"number":31,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"设置当前工作目录的主要目的是_______。","options":[{"key":"A","text":"节省外存空间"},{"key":"B","text":"节省内存空间"},{"key":"C","text":"加快文件的检索速度"},{"key":"D","text":"加快文件的读/写速度"}],"hasFigure":false,"source":"curated"},{"number":32,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"本地用户通过键盘登陆系统时，首先获得键盘输入信息的程序是______。","options":[{"key":"A","text":"命令解释程序"},{"key":"B","text":"中断处理程序"},{"key":"C","text":"系统调用服务程序"},{"key":"D","text":"用户登录程序"}],"hasFigure":false,"source":"curated"},{"number":33,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下列选项中，不\n．\n属于网络体系结构所描述的内容是______。","options":[{"key":"A","text":"网络的层次"},{"key":"B","text":"每一层使用的协议"},{"key":"C","text":"协议的内部实现细节"},{"key":"D","text":"每一层必须完成的功能"}],"hasFigure":false,"source":"curated"},{"number":34,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"在下图所示的采用“存储-转发”方式的分组交换网络中，所有链路的数据传输速率为100Mbps，分组大小为\n1000B，其中 分组头大小为20B。若主机H1向主机H2发送一个大小为980 000B的文件，则在不考虑分组\n拆装时间和传播延迟的情况下，从H1发送开始到H2接收完为止，需要的时间至少\n．．\n是______。","options":[{"key":"A","text":"80 ms"},{"key":"B","text":"80.08 ms"},{"key":"C","text":"80.16 ms"},{"key":"D","text":"80.24 ms"}],"hasFigure":true,"source":"curated"},{"number":35,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"某自治系统内采用RIP协议，若该自治系统内的路由器R1收到其邻居路由器R2的距离矢量，距离矢量中\n包含信息<net1, 16>，则能得出的结论是______。","options":[{"key":"A","text":"R2可以经过R1到达net1，跳数为17"},{"key":"B","text":"R2可以到达net1，跳数为16"},{"key":"C","text":"R1可以经过R2到达net1，跳数为17"},{"key":"D","text":"R1不能经过R2到达net1"}],"hasFigure":false,"source":"curated"},{"number":36,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若路由器R因为拥塞丢弃IP分组，则此时R可向发出该IP分组的源主机发送的ICM P报文类型是______。","options":[{"key":"A","text":"路由重定向"},{"key":"B","text":"目的不可达"},{"key":"C","text":"源点抑制"},{"key":"D","text":"超时"}],"hasFigure":false,"source":"curated"},{"number":37,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"某网络的IP地址空间为192.168.5.0/24，采用 定长子网划分，子网掩码为255.255.255.248，则该网络中的\n最大子网个数、每个子网内的最大可分配地址个数分别是______。","options":[{"key":"A","text":"32，8"},{"key":"B","text":"32，6"},{"key":"C","text":"8，32"},{"key":"D","text":"8，30"}],"hasFigure":false,"source":"curated"},{"number":38,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下列网络设备中，能够抑制广播风暴的是______。\nI中继器 II集线器\nIII网桥 IV路由器","options":[{"key":"A","text":"仅I和II"},{"key":"B","text":"仅III"},{"key":"C","text":"仅III和IV"},{"key":"D","text":"仅IV"}],"hasFigure":false,"source":"curated"},{"number":39,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"主机甲和主机乙之间已建立了一个TCP连接，T CP最大段长度为1 000字节。若主机甲的当前拥塞窗口为\n4 000字节，在主机甲向主机乙连续发送两个最大段后，成功收到主机乙发送的第一个段的确认段，确认段\n中通告的接收窗口大小为2 000字节，则此时主机甲还可以向主机乙发送的最大字节数是______。","options":[{"key":"A","text":"1 000"},{"key":"B","text":"2 000"},{"key":"C","text":"3 000"},{"key":"D","text":"4 000"}],"hasFigure":false,"source":"curated"},{"number":40,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"如果本地域名服务器无缓存，当采用递归方法解析另一网络某主机域名时，用户主机、\n本地域名服务器发\n送的域名请求消息数分别为______。","options":[{"key":"A","text":"一条、\n一条"},{"key":"B","text":"一条、多条"},{"key":"C","text":"多条 、一条"},{"key":"D","text":"多条 、多条"}],"hasFigure":false,"source":"curated"},{"number":41,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":10,"stem":"（10分）将关键字序列（7、8、30、11、18、9、14）散列存储到散列表中。散列表的存储空间是一个下\n标从0开始的一维数组，散列函数为：H(key) = (key x3) MOD 7，处理冲突采用线性探测再散列法，要求装\n填\n（载）因子为0.7。\n(1) 请画出所构造的散列表。\n(2) 分别计算等概率情况下查找成功和查找不成功的平均查找长度。","options":[],"hasFigure":false,"source":"curated"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":13,"stem":"（13分）设将n（n>1）个整数存放到一维数组R中。试设计一个在时间和空间两方面都尽可能高效的算\n法。将R中保存的序列循环左移p（0<p<n）个位置，即将R中的数据由（X0, X1...Xn-1）变换为 （Xp,\nXp+1 ...Xn-1, X0, X1...Xp-1）。要求：\n(1) 给出算法的基本设计思想。\n(2) 根据设计思想，采用C或C++或JAVA语言描述算法，关键之处给出注释。\n(3) 说明你所设计算法的时间复杂度和空间复杂度。","options":[],"hasFigure":false,"source":"curated"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":11,"stem":"（11分）某计算机字长为16位，主存地址空间大小为128KB，按字编址。采用单字长指令格式，指令各\n字段定义如下：\n15 12 11 6 5 0\nOP Ms Rs Md Rd\n 源操作数 目的操作数\n转移指令采用相对寻址方式，相对偏移量用补码表示，寻址方式定义如下：\nMs/Md 寻址方式 助记符 含义\n000B 寄存器直接 Rn 操作数=（Rn）\n\n王道论坛 www.cskaoyan.com 予人玫瑰 手留余香\n001B 寄存器间接 （Rn） 操作数=（(Rn)）\n010B 寄存器间接、自增 （Rn）+ 操作数=（(Rn)），（Rn）+1→Rn\n011B 相对 D（Rn） 转移目标地址=（PC）+（Rn）\n注：（X）表示存储器地址X或寄存器X的内容。\n请回答下列问题：\n(1) 该指令系统最多可有多少条指令？该计算机最多有多少个通用寄存器？存储器地址寄存器（MAR）和\n存储器数据寄存器（M DR）至少各需要多少位？\n(2) 转移指令的目标地址范围是多少？\n(3) 若操作码0010B表示加法操作（助记符为add），寄存器R4和R5的编号分别为100B和101B，R4的内容\n为1234H，R5的内容为5678H，地址1234H中的内容为5678H，地址5678H中的内容为1234H，则汇编语言为“add\n（R4），（R5）+”（逗号前为源操作数，逗号后为目的操作数）对应的机器码是什么（用十六进制表示）？该指\n令执行后，哪些寄存器和存储单元中的内容会改变？改变后的内容是什么？","options":[],"hasFigure":false,"source":"curated"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":12,"stem":"（12分）某计算机的主存地址空间大小为256M B，按字节编址。指令Cache和数据Cache分离，均有8\n个Cache行，每个Cache行大小为64B，数据Cache采用直接映射方式。现有两个功能相同的程序A和B，\n其伪代码如下所示：\n假定int 类型数据用32位补码表示，程序编译时i，j，su m均分配在寄存器中，数组a按行优先方式存放，\n其\n首地址为320（十进制数）。 请回答下列问题，要求说明理由或给出计算过程。\n(1) 若不考虑用于cache一致性维护和替换算法的控制位，则数据Cache的总容量为\n多少？\n(2) 数组元素a[0][31]和a [1][1]各自所在的主存块对应的Cache行号分别是多少（Cache行号从0开始）？\n(3) 程序A和B的数据访问命中率各是多少？哪个程序的执行时间更短？","options":[],"hasFigure":false,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":7,"stem":"（7分）假设计算机系统采用CSCAN（循环扫描）磁盘调度策略，使用2KB的内存空间记录16 384个磁\n盘块的空闲状态。\n(1) 请说明在上述条件下如何进行磁盘块空闲状态的管理。\n(2) 设某单面磁盘旋转速度为每分钟6000转，每个磁道有100个扇区，相邻磁道间的平均移动时间为1ms。\n若在某时刻，磁头位于100号磁道处，并沿着磁道号增大的方向移动（如下图所示），磁道号请求队列为50，\n90，30，120，对请求队列中的每个磁道需读取1个随机分布的扇区，则读完这4个扇区点共需要多少时间？要\n求给出计算过程。\n(3) 如果将磁盘替换为随机访问的Flash半导体存储器（如U盘、SSD等），是否有比CSCAN更高效的磁\n盘调度策略？若有，给出磁盘调度策略的名称并说明理由；若无，说明理由。\n程序A：\nint a[256][256]\n„„\nint sum_array1()\n{\nint i, j, sum=0;\nfor(i=0; i<256; i++)\nfor(j=0; j<256; j++)\nsum += a[i][j];\nreturn sum;\n}\n程序B：\nint a[256][256]\n„„\nint sum_array2()\n{\nint i, j, sum=0;\nfor(j=0; j<256; j++)\nfor(i=0; i<256; i++)\nsum += a[i][j];\nreturn sum;\n}\n\n0号磁道\n随机分布的某扇区\n100号磁道\n磁头移动方向","options":[],"hasFigure":true,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"（8分）设某计算机的逻辑地址空间和物理地址空间均为64KB，按字节编址。若某进程最多需要6页(Page)\n数据存储空间，页的大小为1KB，操作系统采用固定分配局部置换策略为此进程分配4个页框(Page Fra me)。\n在时刻260前的该进程访问情况如下表所示（访问位即使用位）。\n页号 页框号 装入时刻 访问位\n0 7 130 1\n1 4 230 1\n2 2 200 1\n3 9 160 1\n当该进程执行到时刻260时，要访问逻辑地址为17CA H的数据。请回答下列问题：\n(1) 该逻辑地址对应的页号是多少？\n(2) 若采用先进先出（FIFO）置换算法，该逻辑地址对应的物理地址是多少?要求给出计算过程。\n(3) 若采用时钟（CLOCK）置换算法，该逻辑地址对应的物理地址是多少？要求给出计算过程 （设\n搜索下一页的指针沿顺时针方向移动，且当前指向2号页框，示意图如下） 。\n图3.15 页框示意图","options":[],"hasFigure":true,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":9,"stem":"（9分）某局域网采用CSMA/CD 协议实现介质访问控制，数据传输速率为10Mbps，主机甲和主机乙之间\n的距离为2 km，信号传播速度是200 000 km/s。请回答下列问题，要求说明理由或写出计算过程。\n(1) 若主机甲和主机乙发送数据时发生冲突，则从开始发送数据时刻起，到两台主机均检测到冲突时刻止，\n最短需经过多长时间？最长需经过多长时间（假设主机甲和主机乙发送数据过程中，其他主机不发送数据）？\n(2) 若网络不存在任何冲突与差错，主机甲总是以标准的最长以太网数据帧（1 518字节）向主机乙发送数\n据，主机乙每成功收到一个数据帧后立即向主机甲发送一个64字节的确认帧，主机甲收到确认帧后方可发送下\n一个数据帧。此时主机甲的有效数据传输速率是多少（不考虑以太网的前导码）？\n0号页\n3号页2号页\n1号页\n9号页框 2号页框\n4号页框\n7号页框","options":[],"hasFigure":false,"source":"curated"}]},{"year":2011,"title":"2011年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"设 n 是描述问题规模的非负整数，下面程序片段的时间复杂度是\nx=2；\nwhile（x<n/2）\nx=2*x；","options":[{"key":"A","text":"O(log\n2\nn)"},{"key":"B","text":"O(n)"},{"key":"C","text":"O(nlog\n2\nn)"},{"key":"D","text":"O(n\n2\n)\n解答：A。程序中，执行频率最高的语句为“x=2*x”。设该语句执行了t次，则2\nt+1\n=n/2，\n故\nt=log\n2\n(n/2)-1=log\n2\nn-2= O(log\n2\nn)。"}],"hasFigure":false,"source":"curated"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"元素a，b，c，d，e依次进入初始为空的栈中，若元素进栈后可停留、可出栈，直到所\n有元素都出栈，则在所有可能的出栈序列中，以元素d开头的序列个数是","options":[{"key":"A","text":"3"},{"key":"B","text":"4"},{"key":"C","text":"5"},{"key":"D","text":"6\n解答：B。出栈顺序必为d_c_b_a_，e的顺序不定，在任意一个“_”上都有可能。"}],"hasFigure":false,"source":"curated"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知循环队列存储在一维数组A[0...n-1]中，且队列非空时front和rear分别指向队头\n元素和队尾元素。若初始时队列为空，且要求第1个进入队列的元素存储在A[0]处，则\n初始时front和rear的值分别是","options":[{"key":"A","text":"0,0"},{"key":"B","text":"0，n-1"},{"key":"C","text":"n-1,0"},{"key":"D","text":"n-1，n-1\n解答：B。\n插入元素时，front不变，rear+1.而插入第一个元素之后，队尾要指向尾元\n素，显然，rear初始应该为n-1,front为0。"}],"hasFigure":false,"source":"curated"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若一棵完全二叉树有768个结点，则该二叉树中叶结点的个数是","options":[{"key":"A","text":"257"},{"key":"B","text":"258"},{"key":"C","text":"384"},{"key":"D","text":"385\n解答：C。叶结点数为n，则度为2的结点数为n-1,度为1的结点数为0或1，本题中为1（总\n结点数为偶数），故而即2n=768。"}],"hasFigure":false,"source":"curated"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若一棵二叉树的前序遍历序列和后序遍历序列分别为1,2,3,4和4,3,2,1，则该二叉树的\n中序遍历序列不会是","options":[{"key":"A","text":"1,2,3,4"},{"key":"B","text":"2,3,4,1"},{"key":"C","text":"3,2,4,1"},{"key":"D","text":"4,3,2,1\n解答：C。由前序和后序遍历序列可知3为根结点，故（1,2）为左子树，（4）为右子树，\nC不可能。或画图即可得出结果。"}],"hasFigure":false,"source":"curated"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知一棵有2011个结点的树，其叶结点个数为116，该树对应的二叉树中无右孩子的结\n点个数是","options":[{"key":"A","text":"115"},{"key":"B","text":"116"},{"key":"C","text":"1895"},{"key":"D","text":"1896\n解答：D。\n本题可采用特殊情况法解。设题意中的树是如下图所示的结构，则对应的二\n叉树中仅有前115个叶结点有右孩子。\n„„\n共116个叶结点\n共\n1895\n个中间结点"}],"hasFigure":false,"source":"curated"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对于下列关键字序列，不可能构成某二叉排序树中一条查找路径的序列是","options":[{"key":"A","text":"95,22,91,24,94,71"},{"key":"B","text":"92,20,91,34,88,35"},{"key":"C","text":"21,89,77,29,36,38"},{"key":"D","text":"12,25,71,68,33,34\n\n解答：A。选项A中，当查到91后再向24查找，说明这一条路径之后查找的数都要比91小，\n后面的94就错了。"}],"hasFigure":false,"source":"curated"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列关于图的叙述中，正确的是\nI. 回路是简单路径\nII．存储稀疏图，用邻接矩阵比邻接表更省空间\nIII．若有向图中存在拓扑序列，则该图不存在回路","options":[{"key":"A","text":"仅II"},{"key":"B","text":"仅I、II"},{"key":"C","text":"仅III"},{"key":"D","text":"仅I、III\n解答：C。I\n.回路对应于路径，简单回路对应于简单路径；II．刚好相反；III．拓扑有\n序的必要条件。故选C。"}],"hasFigure":true,"source":"curated"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"为提高散列（Hash）表的查找效率，可以采取的正确措施是\nI. 增大装填（载）因子\nII．设计冲突（碰撞）少的散列函数\nIII．处理冲突（碰撞）时避免产生聚集（堆积）现象","options":[{"key":"A","text":"仅I"},{"key":"B","text":"仅II"},{"key":"C","text":"仅I、II"},{"key":"D","text":"仅II、III\n解答：B。III错在“避免”二字。"}],"hasFigure":false,"source":"curated"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"为实现快速排序算法，待排序序列宜采用的存储方式是","options":[{"key":"A","text":"顺序存储"},{"key":"B","text":"散列存储"},{"key":"C","text":"链式存储"},{"key":"D","text":"索引存储\n解答：\nA。内部排序采用顺序存储结构。"}],"hasFigure":false,"source":"curated"},{"number":11,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"已知序列25,13,10,12,9是大根堆，在序列尾部插入新元素18，将其再调整为大根堆，\n调整过程中元素之间进行的比较次数是","options":[{"key":"A","text":"1"},{"key":"B","text":"2"},{"key":"C","text":"4"},{"key":"D","text":"5\n解答：B。\n首先与10比较，交换位置，再与25比较，不交换位置。比较了二次。"}],"hasFigure":false,"source":"curated"},{"number":12,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列选项中，描述浮点数操作速度指标的是","options":[{"key":"A","text":"MIPS"},{"key":"B","text":"CPI"},{"key":"C","text":"IPC"},{"key":"D","text":"MFLOPS\n解答：D。\n送分题。"}],"hasFigure":false,"source":"curated"},{"number":13,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"float型数据通常用IEEE 754单精度浮点数格式表示。若编译器将float型变量x分配在\n一个32位浮点寄存器FR1中，且x=-8.25，则FR1的内容是","options":[{"key":"A","text":"C104 0000H"},{"key":"B","text":"C242 0000H"},{"key":"C","text":"C184 0000H"},{"key":"D","text":"C1C2 0000H\n解答：A。x的二进制表示为-1000.01﹦-1.000 01×2\n11\n根据IEEE754标准隐藏最高位的\n“\n1”，又E-127=3，所以E=130=1000 0010\n（2）\n数据存储为1位数符+8位阶码（含阶符）+23位\n尾数。\n故FR1内容为1 10000 0010 0000 10000 0000 0000 0000 000\n即\n1100 0001 0000 0100 0000 0000 0000 0000，即C104000H"}],"hasFigure":false,"source":"curated"},{"number":14,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列各类存储器中，不采用随机存取方式的是","options":[{"key":"A","text":"EPROM"},{"key":"B","text":"CDROM"},{"key":"C","text":"DRAM"},{"key":"D","text":"SRAM\n解答：B。光盘采用顺序存取方式。"}],"hasFigure":false,"source":"curated"},{"number":15,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机存储器按字节编址，主存地址空间大小为64MB，现用4M×8位的RAM芯片组成32MB\n的主存储器，则存储器地址寄存器MAR的位数至少是","options":[{"key":"A","text":"22位"},{"key":"B","text":"23位"},{"key":"C","text":"25位"},{"key":"D","text":"26位\n解答：D。64MB的主存地址空间，故而MAR的寻址范围是64M，故而是26位。而实际的主存\n的空间不能代表MAR的位数。"}],"hasFigure":false,"source":"curated"},{"number":16,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"偏移寻址通过将某个寄存器内容与一个形式地址相加而生成有效地址。下列寻址方式中，\n不\n．\n属于偏移寻址方式的是","options":[{"key":"A","text":"间接寻址"},{"key":"B","text":"基址寻址"},{"key":"C","text":"相对寻址"},{"key":"D","text":"变址寻址\n解答：A。间接寻址不需要寄存器，EA=(A)。基址寻址：EA=A+基址寄存器内同；相对寻\n址：EA﹦A+PC内容；变址寻址：EA﹦A+变址寄存器内容。"}],"hasFigure":false,"source":"curated"},{"number":17,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某机器有一个标志寄存器，其中有进位/借位标志CF、零标志ZF、符号标志SF和溢出标\n志OF，条件转移指令bgt（无符号整数比较大于时转移）的转移条件是","options":[{"key":"A","text":"1CF OF"},{"key":"B","text":"1SF ZF"},{"key":"C","text":"1CF ZF"},{"key":"D","text":"1CF SF\n\n解答：C。无符号整数比较，如A>B，则A-B无进位/借位，也不为0。故而CF和ZF均为0。"}],"hasFigure":false,"source":"curated"},{"number":18,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列给出的指令系统特点中，有利于实现指令流水线的是\nI. 指令格式规整且长度一致 II．指令和数据按边界对齐存放\nIII．\n只有Load/Store指令才能对操作数进行存储访问","options":[{"key":"A","text":"仅I、II"},{"key":"B","text":"仅II、III"},{"key":"C","text":"仅I、III"},{"key":"D","text":"I、II、III\n解答：D。指令定长、对齐、仅Load/Store指令访存，以上三个都是RISC的特征。均能\n够有效的简化流水线的复杂度。"}],"hasFigure":false,"source":"curated"},{"number":19,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"假定不采用Cache和指令预取技术，且机器处于“开中断”状态，则在下列有关指令执\n行的叙述中，\n错误\n．\n．\n的是","options":[{"key":"A","text":"每个指令周期中CPU都至少访问内存一次"},{"key":"B","text":"每个指令周期一定大于或等于一个CPU时钟周期"},{"key":"C","text":"空操作指令的指令周期中任何寄存器的内容都不会被改变"},{"key":"D","text":"当前程序在每条指令执行结束时都可能被外部中断打断\n解答：C。会自动加1，A取指令要访存、B时钟周期对指令不可分割。"}],"hasFigure":false,"source":"curated"},{"number":20,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"在系统总线的数据线上，不\n．\n可能传输的是","options":[{"key":"A","text":"指令"},{"key":"B","text":"操作数"},{"key":"C","text":"握手（应答）信号"},{"key":"D","text":"中断类型号\n解答：C。握手（应答）信号在通信总线上传输。"}],"hasFigure":false,"source":"curated"},{"number":21,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机有五级中断L\n4\n～L\n0\n，中断屏蔽字为M\n4\nM\n3\nM\n2\nM\n1\nM\n0\n，M\ni\n=1（0≤i≤4）表示对L\ni\n级中断\n进行屏蔽。若中断响应优先级从高到低的顺序是L\n4\n→L\n0\n→L\n2\n→L\n1\n→L\n3\n，则L\n1\n的中断处理程\n序中设置的中断屏蔽字是","options":[{"key":"A","text":"11110"},{"key":"B","text":"01101"},{"key":"C","text":"00011"},{"key":"D","text":"01010\n解答：D。高等级置0表示可被中断，比该等级低的置1表示不可被中断。"}],"hasFigure":false,"source":"curated"},{"number":22,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机处理器主频为50MHz，采用定时查询方式控制设备A的I/O，查询程序运行一次\n所用的时钟周期\n数至少为500。在设备A工作期间，为保证数据不丢失，每秒需对其查询\n至少200次，则CPU用于设备A的I/O的时间占整个CPU时间的百分比至少是","options":[{"key":"A","text":"0.02%"},{"key":"B","text":"0.05%"},{"key":"C","text":"0.20%"},{"key":"D","text":"0.50%\n解答：C。每秒200次查询，每次500个周期，则每秒最少\n200×500﹦10 0000个周期，10\n0000÷50M=0.20%。"}],"hasFigure":false,"source":"curated"},{"number":23,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列选项中，满足短任务优先且不会发生饥饿现象的调度算法是","options":[{"key":"A","text":"先来先服务"},{"key":"B","text":"高响应比优先"},{"key":"C","text":"时间片轮转"},{"key":"D","text":"非抢占式短任务优先\n解答：B。响应比=作业响应时间/作业执行时间 =(作业执行时间+作业等待时间)/作业执\n行时间。高响应比算法，在等待时间相同情况下，作业执行时间越少，响应比越高，优先执\n行，满足短任务优先。随着等待时间增加，响应比也会变大，执行机会就增大，所以不会产\n生饥饿现象。先来先服务和时间片轮转不符合短任务优先，非抢占式短任务优先会产生饥饿\n现象。"}],"hasFigure":false,"source":"curated"},{"number":24,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列选项中，在用户态执行的是","options":[{"key":"A","text":"命令解释程序"},{"key":"B","text":"缺页处理程序"},{"key":"C","text":"进程调度程序"},{"key":"D","text":"时钟中断处理程序\n解答：A。缺页处理程序和时钟中断都属于中断，在核心态执行。进程调度属于系统调\n用在核心态执行，命令解释程序属于命令接口，它在用户态执行。"}],"hasFigure":false,"source":"curated"},{"number":25,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"在支持多线程的系统中，进程P创建的若干个线程不能共享的是","options":[{"key":"A","text":"进程P的代码段"},{"key":"B","text":"进程P中打开的文件"},{"key":"C","text":"进程P的全局变量"},{"key":"D","text":"进程P中某线程的栈指针\n解答：D。进程中某线程的栈指针，对其它线程透明，不能与其它线程共享。"}],"hasFigure":false,"source":"curated"},{"number":26,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"用户程序发出磁盘I/O请求后，系统的正确处理流程是","options":[{"key":"A","text":"用户程序→系统调用处理程序→中断处理程序→设备驱动程序"},{"key":"B","text":"用户程序→系统调用处理程序→设备驱动程序→中断处理程序"},{"key":"C","text":"用户程序→设备驱动程序→系统调用处理程序→中断处理程序"},{"key":"D","text":"用户程序→设备驱动程序→中断处理程序→系统调用处理程序\n解答：B。输入／输出软件一般从上到下分为四个层次：用户层、与设备无关软件层、\n设备驱动程序以及中断处理程序。与设备无关软件层也就是系统调用的处理程序。所以争取\n处理流程为B选项。"}],"hasFigure":false,"source":"curated"},{"number":27,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某时刻进程的资源使用情况如下表所示。\n此时的安全序列是","options":[{"key":"A","text":"P1,P2,P3,P4"},{"key":"B","text":"P1,P3,P2,P4"},{"key":"C","text":"P1,P4,P3,P2"},{"key":"D","text":"不存在\n解答：D。使用银行家算法得，不存在安全序列。"}],"hasFigure":true,"source":"curated"},{"number":28,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"在缺页处理过程中，操作系统执行的操作可能是\nI. 修改页表 II．磁盘I/O III．分配页框","options":[{"key":"A","text":"仅I、II"},{"key":"B","text":"仅II"},{"key":"C","text":"仅III"},{"key":"D","text":"I、II和III\n解答：D。缺页中断调入新页面，肯定要修改页表项和分配页框，所以I、ＩＩＩ可能发\n生，同时内存没有页面，需要从外存读入，会发生磁盘I/O。"}],"hasFigure":false,"source":"curated"},{"number":29,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"当系统发生抖动（thrashing）时，可用采取的有效措施是\nI. 撤销部分进程\nII．增加磁盘交换区的容量\nIII．\n提高用户进程的优先级","options":[{"key":"A","text":"仅I"},{"key":"B","text":"仅II"},{"key":"C","text":"仅III"},{"key":"D","text":"仅I、II\n解答：A。在具有对换功能的操作系统中，通常把外存分为文件区和对换区。前者用于\n存放文件，后者用于存放从内存换出的进程。抖动现象是指刚刚被换出的页很快又要被访问\n为此，又要换出其他页，而该页又快被访问，如此频繁的置换页面，以致大部分时间都花在\n页面置换上。撤销部分进程可以减少所要用到的页面数，防止抖动。对换区大小和进程优先\n级都与抖动无关。"}],"hasFigure":false,"source":"curated"},{"number":30,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"在虚拟内存管理中，地址变换机构将逻辑地址变换为物理地址，形成该逻辑地址的阶段\n是","options":[{"key":"A","text":"编辑"},{"key":"B","text":"编译"},{"key":"C","text":"链接"},{"key":"D","text":"装载\n解答：B。编译过程指编译程序将用户源代码编译成目标模块。源地址编译成目标程序\n时，会形成逻辑地址\n。"}],"hasFigure":false,"source":"curated"},{"number":31,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某文件占 10 个磁盘块，现要把该文件磁盘块逐个读入主存缓冲区，并送用户区进行分\n析，假设一个缓冲区与一个磁盘块大小相同，把一个磁盘块读入缓冲区的时间为100us，\n 进\n程\n 已分配资源 尚需分配 可用资源\n R1 R2 R3 R1 R2 R3 R1 R2 R3\nP1 2 0 0 0 0 1\n 0 2 1\n P2 1 2 0 1 3 2\n P3 0 1 1 1 3 1\n P4 0 0 1 2 0 0\n\n将缓冲区的数据传送到用户区的时间是50us，CPU对一块数据进行分析的时间为50us。\n在单缓冲区和双缓冲区结构下，读入并分析完该文件的时间分别是","options":[{"key":"A","text":"1500us、1000us"},{"key":"B","text":"1550us、1100us"},{"key":"C","text":"1550us、1550us"},{"key":"D","text":"2000us、2000us\n解答：B。单缓冲区下当上一个磁盘块从缓冲区读入用户区完成时下一磁盘块才能开始\n读入，也就是当最后一块磁盘块读入用户区完毕时所用时间为１５０×１０＝１５００。加\n上处理最后一个磁盘块的时间５０为１５５０。双缓冲区下，不存在等待磁盘块从缓冲区读\n入用户区的问题，也就是１００×１０＋１００＝１１００。"}],"hasFigure":false,"source":"curated"},{"number":32,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"有两个并发执行的进程P1和P2，共享初值为1的变量x。P1对x加1，P2对x减1。加1和减1\n操作的指令序列分别如下所示。\n// 加1操作 // 减1操作\nload R1，x // 取x到寄存器R1中 load R2，x\ninc R1 dec R2\nstore x\n，R1 // 将R1的内容存入x store x，R2\n 两个操作完成后，x的值","options":[{"key":"A","text":"可能为-1或3"},{"key":"B","text":"只能为1"},{"key":"C","text":"可能为0、1或2"},{"key":"D","text":"可能为-1、0、1或2\n解答：C。将P1\n中3条语句变为1,2,3，P2中3条语句编为4，5，6。则依次执行1,2,3,4,5\n得结果1，依次执行1,2,4,5,6,3得结果2，执行4，5，1，2，3，6得结果0。结果-1不可能得\n出，选\nC。"}],"hasFigure":false,"source":"curated"},{"number":33,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"TCP/IP参考模型的网络层提供的是","options":[{"key":"A","text":"无连接不可靠的数据报服务"},{"key":"B","text":"无连接可靠的数据报服务"},{"key":"C","text":"有连接不可靠的虚电路服务"},{"key":"D","text":"有连接可靠的虚电路服务\n解答：A。TCP/IP的网络层向上只提供简单灵活的、无连接的、尽最大努力交付的数据\n报\n服务。此外考察IP首部，如果是面向连接的，则应有用于建立连接的字段，但是没有；如\n果提供可靠的服务，则至少应有序号和校验和两个字段，但是IP分组头中也没有（IP首部中\n只是首部校验和）。因此网络层提供的无连接不可靠的数据服务。有连接可靠的服务由传输\n层的\nTCP提供。"}],"hasFigure":false,"source":"curated"},{"number":34,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若某通信链路的数据传输速率为2400bps，采用4相位调制，则该链路的波特率是","options":[{"key":"A","text":"600波特"},{"key":"B","text":"1200波特"},{"key":"C","text":"4800波特"},{"key":"D","text":"9600波特\n解答：B。有4种相位，则一个码元需要由log\n2\n4=2个bit表示，则波特率=比特率/2=1200\n波特。"}],"hasFigure":false,"source":"curated"},{"number":35,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"数据链路层采用选择重传协议（SR）传输数据，发送方已发送了0～3号数据帧，现已收\n到1号帧的确认，而0、2号帧依次超时，则此时需要重传的帧数是","options":[{"key":"A","text":"1"},{"key":"B","text":"2"},{"key":"C","text":"3"},{"key":"D","text":"4\n解答：B。选择重传协议中，接收方逐个地确认正确接收的分组，不管接收到的分组是\n否有序，只要正确接收就发送选择ACK分组进行确认。因此选择重传协议中的ACK分组不再具\n有累积确认的作用。这点要特别注意与GBN协议的区别。此题中只收到\n1号帧的确认，0、2\n号帧超时，由于对于1号帧的确认不具累积确认的作用，因此发送方认为接收方没有收到0、\n2号帧，于是重传这两帧。"}],"hasFigure":false,"source":"curated"},{"number":36,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下列选项中，对正确接收到的数据帧进行确认的MAC协议是","options":[{"key":"A","text":"CSMA"},{"key":"B","text":"CDMA"},{"key":"C","text":"CSMA/C"},{"key":"D","text":"D．CSMA/CA\n解答：D。可以用排除法。首先CDMA即码分多址，是物理层的东西；CSMA/CD即带冲突检\n测的载波监听多路访问，这个应该比较熟悉，接收方并不需要确认；CSMA，既然\nCSMA/CD是\n其超集，CSMA/CD没有的东西，CSMA自然也没有。于是排除法选D。CSMA/CA是无线局域网标\n准\n802.11中的协议。CSMA/CA利用ACK信号来避免冲突的发生，也就是说，只有当客户端收到\n\n网络上返回的ACK信号后才确认送出的数据已经正确到达目的地址。"}],"hasFigure":false,"source":"curated"},{"number":37,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"某网络拓扑如下图所示，路由器R1只有到达子网192.168.1.0/24的路由。为使R1可以将\nIP\n分组正确地路由到图中所有子网，则在R1中需要增加的一条路由（目的网络，子网掩\n码，下一跳）是","options":[{"key":"A","text":"192.168.2.0 255.255.255.128 192.168.1.1"},{"key":"B","text":"192.168.2.0 255.255.255.0 192.168.1.1"},{"key":"C","text":"192.168.2.0 255.255.255.128 192.168.1.2"},{"key":"D","text":"192.168.2.0 255.255.255.0 192.168.1.2\n解答：D。此题主要考察路由聚合。要使R1能够正确将分组路由到所有子网，则R1中需\n要有到\n192.168.2.0/25和192.168.2.128/25的路由。观察发现网络192.168.2.0/25和\n192.168.2.128/25的网络号的前24位都相同，于是可以聚合成超网192.168.2.0/24。从图中\n可以看出下一跳地址应该是\n192.168.1.2。"}],"hasFigure":true,"source":"curated"},{"number":38,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"在子网192.168.4.0/30中，能接收目的地址为192.168.4.3的IP分组的最大主机数是","options":[{"key":"A","text":"0"},{"key":"B","text":"1"},{"key":"C","text":"2"},{"key":"D","text":"4\n解答：C。首先分析192.168.4.0/30这个网络。主机号占两位，地址范围192.168.4.0/30~\n192.168.4.3/30\n，即可以容纳（4-2=2）个主机。主机位为全1时，即192.168.4.3，是广播\n地址，因此网内所有主机都能收到，因此选C。"}],"hasFigure":false,"source":"curated"},{"number":39,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"主机甲向主机乙发送一个(SYN＝1，seq＝11220)的TCP段，期望与主机乙建立TCP连接，\n若主机乙接受该连接请求，则主机乙向主机甲发送的正确的TCP段可能是","options":[{"key":"A","text":"(SYN＝0，ACK＝0，seq＝11221，ack＝11221)"},{"key":"B","text":"(SYN＝1，ACK＝1，seq＝11220，ack＝11220)"},{"key":"C","text":"(SYN＝1，ACK＝1，seq＝11221，ack＝11221)"},{"key":"D","text":"(SYN＝0，ACK＝0，seq＝11220，ack＝11220)\n解答：C。主机乙收到连接请求报文后，如同意连接，则向甲发送确认。在确认报文段\n中应把SYN位和ACK位都置1，确认号是甲发送的TCP段的初始序号seq=11220加1，即为ack=\n11221，同时也要选择并消耗一个初始序号seq，seq值由主机乙的TCP进程确定，本题取seq=\n11221与确认号、甲请求报文段的序号没有任何关系。"}],"hasFigure":false,"source":"curated"},{"number":40,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"主机甲与主机乙之间已建立一个TCP连接，主机甲向主机乙发送了3个连续的TCP段，分\n别包含300字节、400字节和500字节的有效载荷，第3个段的序号为900。若主机乙仅正\n确接收到第1和第3个段，则主机乙发送给主机甲的确认序号是","options":[{"key":"A","text":"300"},{"key":"B","text":"500"},{"key":"C","text":"1200"},{"key":"D","text":"1400\n解答：B。TCP段首部中的序号字段是指本报文段所发送的数据的第一个字节的序号。第\n三个段的序号为900，则第二个段的序号为900-400=500。而确认号是期待收到对方下一个报\n文段的第一个字节的序号。现在主机乙期待收到第二个段，故甲的确认号是500。"}],"hasFigure":false,"source":"curated"},{"number":41,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":8,"stem":"（8分）已知有6个顶点（顶点编号为0～\n5）的有向带权图G，其邻接矩阵A为上三角\n\n矩阵，按行为主序（行优先）保存在如下的一维数组中。\n4 6 ∞ ∞ ∞ 5 ∞ ∞ ∞ 4 3 ∞ ∞ 3 3\n要求：\n（1）写出图G的邻接矩阵A。\n（2）画出有向带权图G。\n（3）求图G的关键路径，并计算该关键路径的长度。\n解答：\n（1）图G的邻接矩阵A如下所示。\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n0\n30\n30\n340\n50\n640\nA\n（2）有向带权图G如下图所示。\n52\n3\n4\n0\n1\n6\n4\n5\n4\n3\n3\n3\n（3）关键路径为01235（如下图所示粗线表示），长度为4+5+4+3=16。\n52\n3\n4\n0\n1\n6\n4\n5\n4\n3\n3\n3","options":[],"hasFigure":true,"source":"curated"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"（15分）一个长度为L（L≥1）的升序序列S，处在第\n \n2/L\n个位置的数称为S的中位数。\n例如，若序列S1=（11,13,15,17,19），则S1的中位数是15，两个序列的中位数是含它\n们所有元素的升序序列的中位数。例如，若S2=（2,4,6,8,20），则S1和S2的中位数\n是11\n。现在有两个等长升序序列A和B，试设计一个在时间和空间两方面都尽可能高效\n的算法，找出两个序列A和B的中位数。要求：\n（1）给出算法的基本设计思想。\n（2）根据设计思想，采用C或C++或JAVA语言描述算法，关键之处给出注释。\n（3）说明你所设计算法的时间复杂度和空间复杂度。\n解答：\n（\n1）算法的基本设计思想如下。\n分别求出序列A和B的中位数，设为a和b，求序列A和B的中位数过程如下：\n1）若a=b，则a或b即为所求中位数，算法结束。\n2）若a<b，则舍弃序列A中较小的一半，同时舍弃序列B中较大的一半,要求舍弃的长\n度相等；\n3）\n若a>b，则舍弃序列A中较大的一半，同时舍弃序列B中较小的一半，要求舍弃的\n\n长度相等；\n在保留的两个升序序列中，重复过程1）、2）、3），直到两个序列中只含一个元素时为\n止\n，较小者即为所求的中位数。\n（2）算法的实现如下：\nint M_Search(int A[],int B[],int n){\nint s1=0,d1=n-1,m1,s2=1,d2=n-1,m2;\n//分别表示序列A和B的首位数、末位数和中位数\nwhile(s1!=d1||s2!=d2){\nm1=(s1+d1)/2;\nm2=(s2+d2)/2;\nif(A[m1]==B[m2])\nreturn A[m1]; //满足条件1）\nif(A[m1]<B[m2]){ //满足条件2)\nif((s1+d1)%2==0) { //若元素个数为奇数\ns1=m1; //舍弃A中间点以前的部分且保留中间点\nd2=m2; //舍弃B中间点以后的部分且保留中间点\n}\nelse{ //元素个数为偶数\ns1=m1+1; //舍弃A中间点及中间点以前部分\nd2=m2; //舍弃B中间点以后部分且保留中间点\n}\n}\nelse{ //满足条件3）\nif((s1+d1)%2==0) { //若元素个数为奇数\nd1=m1; //舍弃A中间点以后的部分且保留中间点\ns2=m2; //舍弃B中间点以前的部分且保留中间点\n}\nelse{ //元素个数为偶数\nd1=m1+1; //舍弃A中间点以后部分且保留中间点\ns2=m2; //舍弃B中间点及中间点以前部分\n}\n}\n}\nreturn A[s1]<B[s2]? A[s1]:B[s2];\n}\n（\n3）算法的时间复杂度为O(log\n2\nn)，空间复杂度为O(1)。","options":[],"hasFigure":false,"source":"curated"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":11,"stem":"（11分）假定在一个8位字长的计算机中运行如下类C程序段：\nunsigned int x = 134;\nunsigned int y = 246;\nint m = x;\nint n = y;\n\nunsigned int z1 = x-y;\nunsigned int z2 = x+y;\nint k1 = m-n;\nint k2 = m+n;\n\n若编译器编译时将8个8位寄存器R1～R8分别分配给变量x、y、m、n、z1、z2、k1\n和k2。请回答下列问题。（提示：带符号整数用补码表示）\n（\n1）执行上述程序段后，寄存器R1、R5和R6的内容分别是什么？（用十六进制表示）\n（2）执行上述程序段后，变量m和k1的值分别是多少？（用十进制表示）\n（3）上述程序段涉及带符号整数加/减、无符号整数加/减运算，这四种运算能否利用\n同一个加法器辅助电路实现？简述理由。\n（4）计算机内部如何判断带符号整数加/减运算的结果是否发生溢出？上述程序段中，\n哪些带符号整数运算语句的执行结果会发生溢出？\n解答：\n（\n1） R1=134=86H, R5=90H, R6=7CH；\n134=1000 0110B=86H；x-y=1000 0110B-1111 0110B=1001 0000B=90H；x+y=1000\n0110B+1111 0110B=0111 1100B（溢出）\n（\n2）m=-122,k1=-112\nm=1000 0110B，做高位为符号位，则m的原码为1111 1010B=-122；n=1111 0110B\nn的原码为1000 1001=-10；k1=m-n=-112。\n（3）无符号数和有符号数都是以补码的形式存储，加减运算没有区别（不考虑溢出情况时），\n只是输出的时候若是有符号数的最高位是符号位。\n减法运算求\n[-x]\n补\n的时候，是连同符号位一起按位取反末位加1，但是如果有溢出情况，\n这两者是有区别的，所以可以利用同一个加法器实现，但是溢出判断电路不同。\n（\n4）判断方法是如果最高位进位和符号位的进位不同，则为溢出；“int k2=m+n;”会溢出；\n三种方法可以判断溢出，双符号位、最高位进位、符号相同操作数的运算后与原操作数\n的符号不同则溢出","options":[],"hasFigure":false,"source":"curated"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":12,"stem":"（12分）某计算机存储器按字节编址，虚拟（逻辑）地址空间大小为16MB，主存（物\n理）地址空间大小为1MB，页面大小为4KB；\nCache采用直接映射方式，共8行；主\n存与Cache之间交换的块大小为32B。系统运行到某一时刻时，页表的部分内容和Cache\n的部分内容分别如题44-a图、题44-b图所示，图中页框号及标记字段的内容为十六进\n制形式。\n\n虚页号 有效位 页框号 ... 行 号 有效位 标记 ...\n0\n 00\n1 1 1\n2 22\n3\n 33\n4 44\n5 55\n6 66\n7 77\n 题44-a图 页表的部分内容 题44-b图 Cache的部分内容\n请回答下列问题。\n\n（1）虚拟地址共有几位，哪几位表示虚页号？物理地址共有几位，哪几位表示页框号\n（物理页号）？\n（2）使用物理地址访问Cache时，物理地址应划分成哪几个字段？要求说明每个字段\n的位数及在物理地址中的位置。\n（\n3）虚拟地址001C60H所在的页面是否在主存中？若在主存中，则该虚拟地址对应的\n物理地址是什么？访问该地址时是否Cache命中？要求说明理由。\n 1 06 ...\n 1 04 ...\n 1 15 ...\n 1 02 ...\n 0 - ...\n 1 2B ...\n 0 - ...\n 1 32 ...\n 1 020 ...\n 0 - ...\n 1 01D ...\n 1 105 ...\n 1 064 ...\n 1 14D ...\n 0 - ...\n 1 27A ...\n\n（4）假定为该机配置一个4路组相联的TLB共可存放8个页表项，若其当前内容（十\n六进制）如题44-c图所示，则此时虚拟地址024BACH所在的页面是否存在主存\n中？要求说明理由。\n\n组号 有效位 标记 页框号 有效位 标记 页框号 有效位 标记 页框号 有效位 标记 页框号\n0\n1\n 题44-c图 TLB的部分内容\n解答：\n（1）24位、前12位；20位、前8位。\n16M=224故虚拟地址24位，4K=212，故页内地址12位，所以虚页号为前12位；1M=220\n故物理地址20位，\n20-12=8，故前8位为页框号。\n（2）\n主存字块标记（12bit）、cache字块标记（3bit）、字块内地址（5bit）\n物理地址20位，其中，块大小为32B=25B故块内地址5位；cache共8行，8=23，故\n字块标记为3位；20-5-2=12，故主存字块标记为12位。\n（\n3） 在主存中，04C60H, 不命中，没有04C的标记字段\n001C60H中虚页号为001H=1，查页表知其有效位为1，在内存中；该物理地址对应的也\n表项中，页框号为04H故物理地址为04C60H；物理地址04C60H在直接映射方式下，对应的\n行号为4，有效位为1但是标记位为064H\n≠04CH故不命中。\n（\n4）在，012的那个标记是对的。\n思路： 标记11位组地址1位页内地址12位，前12位为0000 0010 0100，组地址位为\n0，第0组中存在标记为012的页，其页框号为1F，故024BACH所在的页面存在主存中。","options":[],"hasFigure":true,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"（8分）某银行提供1个服务窗口和10个供顾客等待的座位。顾客到达银行时，若有空\n座位，则到取号机上领取一个号，等待叫号。取号机每次仅允许一位顾客使用。当营业\n员空闲时，通过叫号选取一位顾客，并为其服务。顾客和营业员的活动过程描述如下：\ncobegin\n{\nprocess 顾客i\n{\n从取号机获取一个号码；\n等待叫号；\n获取服务；\n}\nprocess 营业员\n{\nwhile（TRUE）\n{\n叫号；\n为客户服务；\n}\n}\n }coend\n请添加必要的信号量和P、V（或wait()、signal()）操作，实现上述过程中的互斥与同步。\n0 - - 1 001 15 0 - - 1 012 1F\n1 013 2D 0 - - 1 008 7E 0 - -\n\n要求写出完整的过程，说明信号量的含义并赋初值。\n解答：\nsemaphore seets = 10, // 有10个坐位的资源信号量\nmutex = 1, // 取号机互斥信号量\nhaveCustom = 0; // 顾客与营业员同步，无顾客时营业员休息\nprocess 顾客\n{\nP(seets); // 等空位\nP(mutex); // 申请使用取号机\n从取号机上取号;\nV(mutex); // 取号完毕\nV(haveCustom); // 通知营业员有新顾客到来\n等待营业员叫号;\nV(seets); // 离开坐位\n 接受服务；\n}\nprocess 营业员\n{\n while(True)\n {\nP(haveCustom); // 没有顾客则休息\n叫号;\n为顾客服务;\n }\n}","options":[],"hasFigure":false,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":7,"stem":"（7分）某文件系统为一级目录结构，文件的数据一次性写入磁盘，已写入的文件不可\n修改，但可多次创建新文件。请回答如下问题。\n（1）在连续、链式、索引三种文件的数据块组织方式中，哪种更合适？要求说明理由。\n为定位文件数据块，需要FCB中设计哪些相关描述字段？\n（2）为快速找到文件，对于FCB，是集中存储好，还是与对应的文件数据块连续存储\n好？要求说明理由。\n解答：\n（1） 连续更合适,因为一次写入不存在插入问题,连续的数据块组织方式完全可以满足一次\n性写入磁盘。同时连续文件组织方式减少了其他不必要的空间开销，而连续的组织方式顺序\n查找读取速度是最快的。\n\n（2）FCB集中存储好。目录是存在磁盘上的，所以检索目录的时候需要访问磁盘，速度很\n慢；集中存储是将文件控制块的一部分数据分解出去，存在另一个数据结构中，而在目录中\n仅留下文件的基本信息和指向该数据结构的指针，这样一来就有效地缩短减少了目录的体\n积，减少了目录在磁盘中的块数，于是检索目录时读取磁盘的次数也减少，于是就加快了检\n索目录的次数。","options":[],"hasFigure":false,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":9,"stem":"（9分）某主机的MAC地址为00-15-C5-C1-5E-28，IP地址为10.2.128.100（私有地址）。\n题47\n-a图是网络拓扑，题47-b图是该主机进行Web请求的1个以太网数据帧前80个\n\n字节的十六进制及ASCII码内容。\n图47-a图 网络拓扑\n0000 00 21 27 21 51 ee 00 15 c5 c1 5e 28 08 00 45 00 .!|!Q... ..^(..E.\n0010 01 ef 11 3b 40 00 80 06 ba 9d 0a 02 80 64 40 aa ...:@... .....d@.\n0020 62 20 04 ff 00 50 e0 e2 00 fa 7b f9 f8 05 50 18 b ...P.. ..{...P.\n0030 fa f0 1a c4 00 00 47 45 54 20 2f 72 66 63 2e 68 ......GE T /rfc.h\n0040 74 6d 6c 20 48 54 54 50 2f 31 2e 31 0d 0a 41 63 tml HTTP /1.1..Ac\n题 47-b图 以太网数据帧（前80字节）\n请参考图中的数据回答以下问题。\n（1）Web服务器的IP地址是什么？该主机的默认网关的MAC地址是什么？\n（2）该主机在构造题47-b图的数据帧时，使用什么协议确定目的MAC地址？封装该\n协议请求报文的以太网帧的目的MAC地址是什么？\n\n（3）假设HTTP/1.1协议以持续的非流水线方式工作，一次请求-响应时间为RTT，\nrfc.html页面引用了5个JPEG小图像，则从发出题47\n-b图中的Web请求开始到\n浏览器收到全部内容为止，需要多少个RTT？\n（4）该帧所封装的IP分组经过路由器R转发时，需修改IP分组头中的哪些字段？\n注：以太网数据帧结构和IP分组头结构分别如题47-c图、题47-d图所示。\n6B 6B 2B 46-1500B 4B\n目的MAC地址 源MAC地址 类型 数 据 CRC\n题47-c图 以太网帧结构\n比特 0 8 16 24 31\n题47-d IP分组头结构\n解答：\n（1）\n64.170.98.32 00-21-27-21-51-ee\n以太网帧头部6+6+2=14字节，IP数据报首部目的IP地址字段前有4*4=16字节，从以\n太网数据帧第一字节开始数14+16=30字节，得目的IP地址40 aa 62 20(十六进制)，转换\n为十进制得64.170.98.32。以太网帧的前六字节00\n-21-27-21-51-ee是目的MAC地址，本\n题中即为主机的默认网关10.2.128.1端口的MAC地址。\n（\n2）\n\nARP FF-FF-FF-FF-FF-FF\nARP协议解决IP地址到MAC地址的映射问题。主机的ARP进程在本以太网以广播的形\n式发送ARP请求分组，在以太网上广播时，以太网帧的目的地址为全1，即FF-FF\n-FF-FF-FF-FF。\n（\n3）\n6\nHTTP/1.1协议以持续的非流水线方式工作时，服务器在发送响应后仍然在一段时间内\n保持这段连接，客户机在收到前一个响应后才能发送下一个请求。第一个RTT用于请求web\n页面，客户机收到第一个请求的响应后(还有\n五个请求未发送)，每访问一次对象就用去一个\nRTT。故共1+5=6个RTT后浏览器收到全部内容。\n（4）\n源IP地址0a 02 80 64 改为65 0c 7b 0f\n生存时间\n(TTL)减1\n校验和字段重新计算\n私有地址和Internet上的主机通信时，须有NAT路由器进行网络地址转换，把IP数据\n报的源IP地址(本题为私有地址10.2.128.100)转换为NAT路由器的一个全球IP地址(本题\n为101.12.123.15)。因此，源IP地址字段0a 02 80 64变为65 0c 7b 0f。IP数据报每经\n过一个路由器，生存时间TTL值就减1，并重新计算首部校验和。若IP分组的长度超过输\n出链路的MTU，则总长度字段、标志字段、片偏移字段也要发生变化。\n注意，图\n 47-b中每行前4bit是数据帧的字节计数，不属于以太网数据帧的内容。","options":[],"hasFigure":true,"source":"curated"}]},{"year":2012,"title":"2012年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"求整数n(n≥0)阶乘的算法如下，其时间复杂度是 。\nint fact(int n){\nif (n<=1) return 1;\nreturn n*fact(n-1);\n}","options":[{"key":"A","text":"O(log\n2\nn)"},{"key":"B","text":"O(n)"},{"key":"C","text":"O(nlog\n2\nn)"},{"key":"D","text":"O(n\n2\n)"}],"hasFigure":false,"source":"curated"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知操作符包括„+‟、„-‟、„*‟、„/‟、„(‟和„)‟。将中缀表达式a+b-a*((c+d)/e-f)+g转换为等价的后\n缀表达式ab+acd+e/f-*-g+时，用栈来存放暂时还不能确定运算次序的操作符，若栈初始时为空，则转换\n过程中同时保存在栈中的操作符的最大个数是 。","options":[{"key":"A","text":"5"},{"key":"B","text":"7"},{"key":"C","text":"8"},{"key":"D","text":"11"}],"hasFigure":false,"source":"curated"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若一棵二叉树的前序遍历序列为a, e, b, d, c，后序遍历序列为b, c, d, e, a，则根结点的孩子结\n点 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。\n用户1\n①\n②③\n用户1的\n邮件服务器\n用户2的\n邮件服务器\n用户2","options":[{"key":"A","text":"SMTP、SMTP、SMTP"},{"key":"B","text":"POP3、SMTP、POP3"},{"key":"C","text":"POP3、SMTP、SMTP"},{"key":"D","text":"SMTP、SMTP、POP3"}],"hasFigure":true,"source":"curated"},{"number":41,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"设有6个有序表A、B、C、D、E、F，分别含有10、35、40、50、60和200个数据元素，各\n表中元素按升序排列。要求通过5次两两合并，将6个表最终合并成1个升序表，并在最坏情况下比较\n的总次数达到最小。请问答下列问题。\n1）给出完整的合并过程，并求出最坏情况下比较的总次数。\n2）根据你的合并过程，描述N（N≥2）个不等长升序表的合并策略，并说明理由。","options":[],"hasFigure":false,"source":"curated"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"假定采用带头结点的单链表保存单词，当两个单词有相同的后缀时，则可共享相同的后缀存储\n空间，例如，“loading”和“being”的存储映像如下图所示。\n设str1和str2分别指向两个单词所在单链表的头结点，链表结点结构为，请设计一个时\n间上尽可能高效的算法，找出由str1和str2所指向两个链表共同后缀的起始位置（如图中字符i所在结\n点的位置p）。要求：\n1）给出算法的基本设计思想。\n2）根据设计思想，采用C或C++或JAVA语音描述算法，关键之处给出注释。\n3）说明你所设计算法的时间复杂度。","options":[],"hasFigure":true,"source":"curated"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"假定某计算机的CPU主频为80MHz，CPI为4，平均每条指令访存1.5次，主存与Cache之间\n\n6\n交换的块大小为16B，Cache的命中率为99%，存储器总线宽带为32位。请回答下列问题。\n1）该计算机的MIPS数是多少？平均每秒Cache缺失的次数是多少？在不考虑DMA传送的情况下，\n主存带宽至少达到多少才能满足CPU的访存要求？\n2）假定在Cache缺失的情况下访问主存时，存在0.0005%的缺页率，则CPU平均每秒产生多少次\n缺页异常？若页面大小为4KB，每次缺页都需要访问磁盘，访问磁盘时DMA传送采用周期挪用方式，\n磁盘I/O接口的数据缓冲寄存器为32位，则磁盘I/O接口平均每秒发出的DMA请求次数至少是多少？\n3）CPU和DMA控制器同时要求使用存储器 总线时，哪个优先级更高？为什么？\n4）为了提高性能， 主存采用4体低位交叉存储模式，工作时 每1/4个存储周期启动一个体。若每个\n体的存储周期为50ns，则该 主存能提供的最大带宽是多少？","options":[],"hasFigure":false,"source":"curated"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"某16位计算机中，带符号整数用补码表示，数据Cache和指令Cache分离。题44表给出了指\n令系统中部分指令格式，其中Rs和Rd表示寄存器，mem表示存储单元地址，（x）表示寄存器x或存储\n单元x的内容。\n表 指令系统中部分指令格式\n名称 指令的汇编格式 指令功能\n加法指令 ADD Rs，Rd (Rs)+(Rd)->Rd\n算术/逻辑左移 SHL Rd 2*(Rd)->Rd\n算术右移 SHR Rd (Rd)/2->Rd\n取数指令 LOAD Rd, mem (mem)->Rd\n存数指令 STORE Rs, mem (Rs)->mem\n该计算机采用5段流水方式执行指令，各流水段分别是取指（IF）、译码/读寄存器（ID）、执行/计\n算有效地址（EX）、访问存储器（M）和结果写回寄存器（WB），流水线采用“按序发射，按序完成”方\n式，没有采用转发技术处理数据相关，并且同一个寄存器的读和写操作不能在同一个时钟周期内进行。\n请回答下列问题：\n1）若int型变量x的值为-513，存放在寄存器R1中，则执行指令“SHL R1”后，R1的内容是多少？\n（用十六进制表示）\n2）若某个时间段中，有连续的4条指令进入流水线，在其执行过程中没有发生任何阻塞，则执行\n这4条指令所需的时钟周期数为多少？\n3）若高级语言程序中某赋值语句为x=a+b，x、a和b均为int型变量，它们的存储单元地址分别表\n示为[x]、[a]和[b]。该语句对应的指令序列及其在指令流水线中的执行过程如下图所示。\nI1 LOAD R1，[a]\nI2 LOAD R2，[b]\nI3 ADD R1，R2\nI4 STORE R2，[x]\n图 指令序列及其执行过程示意图\n则这4条指令执行过程中，I\n3\n的ID段和I\n4\n的IF段被阻塞的原因各是什么？\n4）若高级语言程序中某赋值语句为x=x*2+a，x和a均为unsigned int类型变量，它们的存储单元\n\n7\n地址分别表示为[x]、[a]，则执行这条语句至少需要多少个时钟周期？要求模仿题44图画出这条语句对\n应的指令序列及其在流水线中的执行过程示意图。","options":[],"hasFigure":true,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"某请求分页系统的局部页面置换策略如下：\n系统从0时刻开始扫描，每隔5个时间单位扫描一轮驻留集（扫描时间忽略不计），本轮没有被访\n问过的页框将被系统回收，并放入到空闲页框链尾，其中内容在下一次分配之前不被清空。当发生缺页\n时，如果该页曾被使用过且还在空闲页链表中，则重新放回进程的驻留集中；否则，从空闲页框链表头\n部取出一个页框。\n假设不考虑其它进程的影响和系统开销。初始时进程驻留集为空。目前系统空闲页框链表中页框号\n依次为32、15、21、41。进程P依次访问的<虚拟页号，访问时刻>是：<1,1>、<3,2>、<0,4>、<0,6>、\n<1,11>、<0,13>、<2,14>。请回答下列问题。\n1）访问<0,4>时，对应的页框号是什么？\n2）访问<1,11>时，对应的页框号是什么？说明理由。\n3）访问<2,14>时，对应的页框号是什么？说明理由。\n4）该策略是否适合于时间局部性好的程序？说明理由。","options":[],"hasFigure":false,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"某文件系统空间的最大容量为4TB（1TB=2\n40\n），以磁盘块为基本分配单位。磁盘块大小为1KB。\n文件控制块（FCB）包含一个512B的索引表区。请回答下列问题。\n1）假设索引表区仅采用直接索引结构，索引表区存放文件占用的磁盘块号，索引表项中块号最少占\n多少字节？可支持的单个文件最大长度是多少字节？\n2）假设索引表区采用如下结构：第0~7字节采用<起始块号，块数>格式表示文件创建时预分配的\n连续存储空间，其中起始块号占6B，块数占2B；剩余504字节采用直接索引结构，一个索引项占6B，\n则可支持的单个文件最大长度是多少字节？为了使单个文件的长度达到最大，请指出起始块号和块数分\n别所占字节数的合理值并说明理由。","options":[],"hasFigure":false,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":8,"stem":"主机H通过快速以太网连接Internet，IP地址为192.168.0.8，服务器S的IP地址为211.68.71.80。\nH与S使用TCP通信时，在H上捕获的其中5个IP分组如 题47-a表所示。\n题47-a表\n编号 IP分组的前40字节内容（十六进制）\n1\n45 00 00 30 01 9b 40 00 80 06 1d e8 c0 a8 00 08 d3 44 47 50\n0b d9 13 88 84 6b 41 c5 00 00 00 00 70 02 43 80 5d b0 00 00\n2\n43 00 00 30 00 00 40 00 31 06 6e 83 d3 44 47 50 c0 a8 00 08\n13 88 0b d9 e0 59 9f ef 84 6b 41 c6 70 12 16 d0 37 e1 00 00\n3\n45 00 00 28 01 9c 40 00 80 06 1d ef c0 a8 00 08 d3 44 47 50\n0b d9 13 88 84 6b 41 c6 e0 59 9f f0 50 f0 43 80 2b 32 00 00\n4\n45 00 00 38 01 9d 40 00 80 06 1d de c0 a8 00 08 d3 44 47 50\n0b d9 13 88 84 6b 41 c6 e0 59 9f f0 50 18 43 80 e6 55 00 00\n5\n45 00 00 28 68 11 40 00 31 06 06 7a d3 44 47 50 c0 a8 00 08\n13 88 0b d9 e0 59 9f f0 84 6b 41 d6 50 10 16 d0 57 d2 00 00\n回答下列问题。\n1）题47-a表中的IP分组中，哪几个是由H发送的？哪几个完成了TCP连接建立过程？哪几个在\n通过快速以太网传输时进行了填充？\n2）根据题47-a表中的IP分组，分析S已经收到的应用层数据字节数是多少？\n3）若题47-a表中的某个IP分组在S发出时的前40字节如题47-b表所示，则该IP分组到达H时\n经过了多少个路由器？\n题47-b表\n\n8\n来自S的分组 45 00 00 28 68 11 40 00 40 06 ec ad d3 44 47 50 ca 76 01 06\n13 88 a1 08 e0 59 9f f0 84 6b 41 d6 50 10 16 d0 b7 d6 00 00\n注：IP分组头和TCP段头结构分别如题47-a图，题47-b图所示。\n题47-a图 IP分组头结构\n题47-b图TCP段头结构\n2012年计算机学科专业基础综合试题","options":[],"hasFigure":true,"source":"curated"}]},{"year":2013,"title":"2013年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知两个长度分别为m和n的升序链表，若将它们合并为一个长度为m+n的降序链表，则\n最坏情况下的时间复杂度是","options":[{"key":"A","text":"()On"},{"key":"B","text":"()O m n"},{"key":"C","text":"(min( , ))Om n"},{"key":"D","text":"(max( , ))Om n"}],"hasFigure":false,"source":"curated"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"一个栈的入栈序列为\n1, 2, 3,,n\n，其出栈序列是\n123\n,,,,\nn\np p pp\n。若\n2\n3p\n，则\n3\np\n可能取值\n的个数是","options":[{"key":"A","text":"3n"},{"key":"B","text":"2n"},{"key":"C","text":"1n"},{"key":"D","text":"无法确定"}],"hasFigure":false,"source":"curated"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若将关键字1，2，3，4，5，6，7依次插入到初始为空的平衡二叉树T中，则T中平衡因\n子为0的分支结点的个数是","options":[{"key":"A","text":"0"},{"key":"B","text":"1"},{"key":"C","text":"2"},{"key":"D","text":"3"}],"hasFigure":false,"source":"curated"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知三叉树T中6个叶结点的权分别是2，3，4，5，6，7，T的带权（外部）路径长度最\n小是","options":[{"key":"A","text":"27"},{"key":"B","text":"46"},{"key":"C","text":"54"},{"key":"D","text":"56"}],"hasFigure":false,"source":"curated"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若X是后序线索二叉树中的叶结点，且X存在左兄弟结点Y，则X的右线索指向的是","options":[{"key":"A","text":"X的父结点"},{"key":"B","text":"以Y为根的子树的最左下结点"},{"key":"C","text":"X的左兄弟结点Y"},{"key":"D","text":"以Y为根的子树的最右下结点"}],"hasFigure":false,"source":"curated"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"在任意一棵非空二叉排序树T\n1\n中，删除某结点\nv\n之后形成二叉排序树T\n2\n，再将\nv\n插入T\n2\n形\n成二叉排序树T\n3\n。下列关于T\n1\n与T\n3\n的叙述中，正确的是\n I. 若\nv\n是T\n1\n的叶结点，则T\n1\n与T\n3\n不同\n II. 若\nv\n是T\n1\n的叶结点，则T\n1\n与T\n3\n相同\n III. 若\nv\n不是T\n1\n的叶结点，则T\n1\n与T\n3\n不同\n IV. 若\nv\n不是T\n1\n的叶结点，则T\n1\n与T\n3\n相同","options":[{"key":"A","text":"仅I、III"},{"key":"B","text":"仅I、IV"},{"key":"C","text":"仅II、III"},{"key":"D","text":"仅II、IV"}],"hasFigure":false,"source":"curated"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"设图的邻接矩阵A如下所示。各顶点的度依次是\n0 1 0 1\n0 0 1 1\n0 1 0 0\n1 0 0 0","options":[{"key":"A","text":"\n\n\n\n\n\n\n\nA. 1，2，1，2"},{"key":"B","text":"2，2，1，1"},{"key":"C","text":"3，4，2，3"},{"key":"D","text":"4，4，2，2"}],"hasFigure":true,"source":"curated"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若对如下无向图进行遍历，则下列选项中，不\n．\n是广度优先遍历序列的是","options":[{"key":"A","text":"h，c，a，b，d，e，g，f"},{"key":"B","text":"e，a，f，g，b，h，c，d"},{"key":"C","text":"d，b，c，a，h，e，f，g"},{"key":"D","text":"a，b，c，d，h，e，f，g"}],"hasFigure":true,"source":"curated"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列AOE网表示一项包含8个活动的工程。通过同时加快若干活动的进度可以缩短整个工\n程的工期。下列选项中，加快其进度就可以缩短工程工期的是","options":[{"key":"A","text":"c和e"},{"key":"B","text":"d和e"},{"key":"C","text":"f和d"},{"key":"D","text":"f和h"}],"hasFigure":false,"source":"curated"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"在一株高度为2的5阶B树中，所含关键字的个数最少是","options":[{"key":"A","text":"5"},{"key":"B","text":"7"},{"key":"C","text":"8"},{"key":"D","text":"14"}],"hasFigure":false,"source":"curated"},{"number":11,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"对给定的关键字序列110，119，007，911，114，120，122进行基数排序，则第2趟分配\n收集后得到的关键字序列是","options":[{"key":"A","text":"007，110，119，114，911，120，122"},{"key":"B","text":"007，110，119，114，911，122，120"},{"key":"C","text":"007，110，911，114，119，120，122"},{"key":"D","text":"110，120，911，122，114，007，119"}],"hasFigure":false,"source":"curated"},{"number":12,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机主频为1.2 GHz，其指令分为4类，它们在基准程序中所占比例及CPI如下表所\n示。\n指令类型 所占比例\nCPI","options":[{"key":"A","text":"50% 2"},{"key":"B","text":"20% 3"},{"key":"C","text":"10% 4"},{"key":"D","text":"20% 5\n\n该机的MIPS数是\n A. 100 B. 200 C. 400 D. 600"}],"hasFigure":true,"source":"curated"},{"number":13,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某数采用IEEE 754单精度浮点数格式表示为C640 0000H，则该数的值是\n2\n4\nc=9\n2\n4\n2\n4\ng=6\na=3\nd=4\ne=6\nb=8\nh=9\nf=10\na\nb\nc d\ne\nf g\nh","options":[{"key":"A","text":"-1.5×2\n13"},{"key":"B","text":"-1.5×2\n12"},{"key":"C","text":"-0.5x×2\n13"},{"key":"D","text":"-0.5×2\n12"}],"hasFigure":false,"source":"curated"},{"number":14,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某字长为8位的计算机中，已知整型变量x、y的机器数分别为[x]\n补\n=1 1110100，[y]\n补\n=1\n0110000。若整型变量z=2*x+y/2，则z的机器数为","options":[{"key":"A","text":"1 1000000"},{"key":"B","text":"0 0100100"},{"key":"C","text":"1 0101010"},{"key":"D","text":"溢出"}],"hasFigure":false,"source":"curated"},{"number":15,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"用海明码对长度为8位的数据进行检/纠错时，若能纠正一位错。则校验位数至少为","options":[{"key":"A","text":"2"},{"key":"B","text":"3"},{"key":"C","text":"4"},{"key":"D","text":"5"}],"hasFigure":false,"source":"curated"},{"number":16,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机主存地址空间大小为256 MB，按字节编址。虚拟地址空间大小为4 GB，采用页\n式存储管理，页面大小为4 KB，TLB（快表）采用全相联映射，有4个页表项，内容如下\n表所示。\n有效位 标记 页框号 „\n0 FF180H 0002H\n„\n1 3FFF1H 0035H\n„\n0 02FF3H 0351H\n„\n1 03FFFH 0153H\n„\n\n则对虚拟地址03FF F180H进行虚实地址变换的结果是","options":[{"key":"A","text":"015 3180H"},{"key":"B","text":"003 5180H"},{"key":"C","text":"TLB缺失"},{"key":"D","text":"缺页"}],"hasFigure":false,"source":"curated"},{"number":17,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"假设变址寄存器R的内容为1000H，指令中的形式地址为2000 H；地址1000H中的内容\n为2000H，地址2000H中的内容为3000H，地址3000 H中的内容为4000H，则变址寻址\n方式下访问到的操作数是","options":[{"key":"A","text":"1000H"},{"key":"B","text":"2000H"},{"key":"C","text":"3000H"},{"key":"D","text":"4000 H"}],"hasFigure":false,"source":"curated"},{"number":18,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某CPU主频为1.03 GHz，采用4级指令流水线，每个流水段的执行需要1个时钟周期。\n假定CPU执行了100条指令，在其执行过程中，没有发生任何流水线阻塞，此时流水线\n的吞吐率为","options":[{"key":"A","text":"0.25×10\n9\n条指令/秒"},{"key":"B","text":"0.97×10\n9\n条指令/秒"},{"key":"C","text":"1.0×10\n9\n条指令/秒"},{"key":"D","text":"1.03 ×10\n9\n条指令/秒"}],"hasFigure":false,"source":"curated"},{"number":19,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列选项中，用于设备和设备控制器（I/O接口）之间互连的接口标准是","options":[{"key":"A","text":"PCI"},{"key":"B","text":"USB"},{"key":"C","text":"AGP"},{"key":"D","text":"PCI-Express"}],"hasFigure":false,"source":"curated"},{"number":20,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列选项中，用于提高RAID可靠性的措施有\n I. 磁盘镜像 II. 条带化 III. 奇偶校验 IV. 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15，p4=0.35。将S保存在一个长度为4的顺序\n表中，采用折半查找法，查找成功时的平均查找长度为2.2。请回答：\n （1）若采用顺序存储结构保存S，且要求平均查找长度更短，则元素应如何排列？应使用\n何种查找方法？查找成功时的平均查找长度是多少？\n （2）若采用链式存储结构保存S，且要求平均查找长度更短，则元素应如何排列？应使用\n何种查找方法？查找成功时的平均查找长度是多少？","options":[],"hasFigure":false,"source":"curated"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":9,"stem":"（9分）某32位计算机，CPU主频为800MHz，Cache命中时的CPI为4，Cache块大小为\n32字节；主存采用8体交叉存储方式，每个体的存储字长为32位、存储周期为40 ns；\n存储器总线宽度为32位，总线时钟频率为200 MHz，支持突发传送总线事务。每次读突\n发传送总线事务的过程包括：送首地址和命令、存储器准备数据、传送数据。每次突发传\n送32字节，传送地址或32位数据均需要一个总线时钟周期。请回答下列问题，要求给出\n理由或计算过程。\n （1）CPU和总线的时钟周期各为多少？总线的带宽（即最大数据传输率）为多少？\n （2）Cache缺失时，需要用几个读突发传送总线事务来完成一个主存块的读取？\n（3）存储器总线完成一次读突发传送总线事务所需的时间是多少？\n（4）若程序BP执行过程中，共执行了100条指令，平均每条指令需进行1.2次访存，\nCache缺失率为5%，不考虑替换等开销，则BP的CPU执行时间是多少？","options":[],"hasFigure":false,"source":"curated"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":14,"stem":"（14分）某计算机采用16位定长指令字格式，其CPU中有一个标志寄存器，其中包含进\n位/借位标志CF、零标志ZF和符号标志NF。假定为该机设计了条件转移指令，其格式如\n\n下：\n\n其中，00000为操作码OP；C、Z和N分别为CF、ZF和NF的对应检测位，某检测位为\n1时表示需检测对应标志，需检测的标志位中只要有一个为1就转移，否则不转移，例\n如，若C=1，Z=0，N=1，则需检测CF和NF的值，当CF=1或NF=1时发生转移；\nOFFSET是相对偏移量，用补码表示。转移执行时，转移目标地址为（PC）+2+2×\nOFFSET；顺序执行时，下条指令地址为（PC）+2。请回答下列问题。\n（1）该计算机存储器按字节编址还是按字编址？该条件转移指令向后（反向）最多可跳转多\n少条指令？\n（2）某条件转移指令的地址为200CH，指令内容如下图所示，若该指令执行时CF=0，\nZF=0，NF=1，则该指令执行后PC的值是多少？若该指令执行时CF=1，ZF=0，NF=0，\n则该指令执行后PC的值又是多少？请给出计算过程。\n\n（3）实现“无符号数比较小于等于时转移”功能的指令中，C、Z和N应各是什么？\n（4）以下是该指令对应的数据通路示意图，要求给出图中部件①~③的名称或功能说明。","options":[],"hasFigure":true,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":7,"stem":"（7分）某博物馆最多可容纳500人同时参观，有一个出入口，该出入口一次仅允许一个人\n通过。参观者的活动描述如下：\n cobegin\n参观者进程i：\n15 11 10 9 8 7 0\n0 0 0 0 0 0 1 1 1 1 1 0 0 0 1 1\n\n15 11 10 9 8 7 0\n0 0 0 0 0 C Z N OFFSET\n\n标志寄存器\n①\nOP C Z N OFFSET\nPC\n符号扩展器\n②\n③\n多路选择器\n加法器\n2\n\n{\n„\n进门；\n„\n参观；\n„\n出门；\n„\n}\ncoend\n请添加必要的信号量和P、V（或wait（）、signal（ ））操作，以实现上述过程中的互斥\n与同步。要求写出完整的过程，说明信号量的含义并赋初值。","options":[],"hasFigure":false,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"（8分）某计算机主存按字节编址，逻辑地址和物理地址都是32位，页表项大小为4字\n节。请回答下列问题。\n（1）若使用一级页表的分页存储管理方式，逻辑地址结构为：\n页号（20位） 页内偏移量（12位）\n\n则页的大小是多少字节？页表最大占用多少字节？\n（2）若使用二级页表的分页存储管理方式，逻辑地址结构为：\n页目录号（10位） 页表索引（10位） 页内偏移量（12位）\n\n设逻辑地址为LA，请分别给出其对应的页目录号和页表索引的表达式。\n（3）采用（1）中的分页存储管理方式，一个代码段起始逻辑地址为0000 8000H，其长度\n为8 KB，被装载到从物理地址0090 0000H开始的连续主存空间中。页表从主存\n0020 0000H开始的物理地址处连续存放，如下图所示（地址大小自下向上递增）。请\n计算出该代码段对应的两个页表项的物理地址、这两个页表项中的页框号以及代码页\n面2的起始物理地址。","options":[],"hasFigure":true,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":9,"stem":"（9分）假设Internet的两个自治系统构成的网络如题47图所示，自治系统ASI由路由器\nR1连接两个子网构成；自治系统AS2由路由器R2、R3互联并连接3个子网构成。各子\n页表\n\n页框号2\n页框号1\n\n代码页面2\n代码页面1\n\n物理地址3\n0090 0000H\n物理地址2\n物理地址1\n\n0020 0000H\n\n网地址、R2的接口名、R1与R3的部分接口IP地址如题47图所示。\n\n题47图 网络拓扑结构\n请回答下列问题。\n（1）假设路由表结构如下表所示。请利用路由聚合技术，给出R2的路由表，要求包括\n到达题47图中所有子网的路由，且路由表中的路由项尽可能少。\n目的网络 下一跳 接口\n\n（2）若R2收到一个目的IP地址为194.17.20.200的IP分组，R2会通过哪个接口转发该\nIP分组？\n（3）R1与R2之间利用哪个路由协议交换路由信息？该路由协议的报文被封装到哪个协\n议的分组中进行传输？\n153.14.5.0/25\n153.14.5.128/25\nAS1\nR1\n153.14.3.2\n194.17.20.0/25\n194.17.20.128/25\nAS2\nR2\n153.14.3.2\n194.17.21.0/24\nR3\nSO\nEO\nS1\n194.17.24.2\n\n计算机学科专业基础综合试题","options":[],"hasFigure":true,"source":"curated"}]},{"year":2014,"title":"2014年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列程序段的时间复杂度是 。\ncount=0;\nfor(k=1;k<=n;k*=2)\nfor(j=1;j<=n;j++)\ncount++;","options":[{"key":"A","text":"O(log\n2\nn)"},{"key":"B","text":"O(n)"},{"key":"C","text":"O(nlog\n2\nn)"},{"key":"D","text":"O(n\n2\n)"}],"hasFigure":false,"source":"curated"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"假设栈初始为空，将中缀表达式a/b+(c*d-e*f)/g转换为等价的后缀表达式的过程中，\n当扫描到f时，栈中的元素依次是 。","options":[{"key":"A","text":"+\n( * -"},{"key":"B","text":"+ ( - *"},{"key":"C","text":"/ + ( * - *"},{"key":"D","text":"/ + - *"}],"hasFigure":false,"source":"curated"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"循环 队列放在一维数组A[0...M-1]中，end1指向队头元素，end2指向队尾元素的后\n一个位置。假设队列两端均可进行入队和出队操作，队列中最多能容纳M-1个元素。初始\n时为空。\n下列判断队空和队满的条件中，正确\n．．\n的是。","options":[{"key":"A","text":"队空：end1 == end2； 队满：end1 == (end2+1)mod M"},{"key":"B","text":"队空：end1 == end2； 队满：end2 == (end1+1)mod (M-1)"},{"key":"C","text":"队空：end2 == (end1+1)mod M； 队满：end1 == (end2+1)mod M"},{"key":"D","text":"队空：end1 == (end2+1)mod M；\n 队满：end2 == (end1+1)mod (M-1)"}],"hasFigure":false,"source":"curated"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若对如下的二叉树进行中序线索化，则结点x的左、右线索指向的结点分别是 。\nx\nb\ne\nc\na\nd","options":[{"key":"A","text":"e、c"},{"key":"B","text":"e、a"},{"key":"C","text":"d、c"},{"key":"D","text":"b、a"}],"hasFigure":false,"source":"curated"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"将森林F转换为对应的二叉树T，F中叶结点的个数等于 。","options":[{"key":"A","text":"T中叶结点的个数"},{"key":"B","text":"T中度为1的结点个数"},{"key":"C","text":"T中左孩子指针为空的结点个数"},{"key":"D","text":"T中右孩子指针为空的结点个数"}],"hasFigure":false,"source":"curated"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"5个字符有如下4种编码方案，不是\n．\n．\n前缀编码的是\n。","options":[{"key":"A","text":"01,0000,0001,001,1"},{"key":"B","text":"011,000,001,010,1"},{"key":"C","text":"000,001,010,011,100"},{"key":"D","text":"0,100,110,1110,1100"}],"hasFigure":false,"source":"curated"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对如下所示的有向图进行拓扑排序，得到的拓扑序列可能是 。","options":[{"key":"A","text":"3,1,2,4,5,6"},{"key":"B","text":"3,1,2,4,6,5"},{"key":"C","text":"3,1,4,2,5,6"},{"key":"D","text":"3,1,4,2,6,5"}],"hasFigure":true,"source":"curated"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"用哈希（散列）方法处理冲突（碰撞）时可能出现堆积（聚集）现象，下列选项中，\n会受堆积现象直接影响的是 。","options":[{"key":"A","text":"存储效率"},{"key":"B","text":"散列函数"},{"key":"C","text":"装填(装载)因子"},{"key":"D","text":"平均查找长度"}],"hasFigure":false,"source":"curated"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"在一棵具有15个关键字的4阶B树中，含关键字的结点个数最多是 。","options":[{"key":"A","text":"5"},{"key":"B","text":"6"},{"key":"C","text":"10"},{"key":"D","text":"15"}],"hasFigure":false,"source":"curated"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"用希尔排序方法对一个数据序列进行排序时，若第1趟排序结果为\n9,1,4,13,7,8,20,23,15，则该 趟\n排序采用的增量（间隔）可能是 。","options":[{"key":"A","text":"2"},{"key":"B","text":"3"},{"key":"C","text":"4"},{"key":"D","text":"5"}],"hasFigure":false,"source":"curated"},{"number":11,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列选项中，不可能是快速排序第2趟排序结果的是 。","options":[{"key":"A","text":"2,3,5,4,6,7,9"},{"key":"B","text":"2,7,5,6,4,3,9"},{"key":"C","text":"3,2,5,4,7,6,9"},{"key":"D","text":"4,2,3,5,7,6,9"}],"hasFigure":false,"source":"curated"},{"number":12,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"程序P在机器M上的执行时间是20秒，编译优化后，P执行的指令数减少到原来\n的70%，而CPI增加到原来的1.2倍，则P在M上的执行时间是\n 。","options":[{"key":"A","text":"8.4秒"},{"key":"B","text":"11.7秒"},{"key":"C","text":"14秒"},{"key":"D","text":"16.8秒"}],"hasFigure":false,"source":"curated"},{"number":13,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"若x=103，y=-25，则下列表达式采用8位定点补码运算实现时，会发生溢出的\n是\n 。","options":[{"key":"A","text":"x+y"},{"key":"B","text":"-x+y"},{"key":"C","text":"x-y"},{"key":"D","text":"-x-y"}],"hasFigure":false,"source":"curated"},{"number":14,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"float型数据据常用IEEE754单精度浮点格式表示。假设两个float型变量x和y分\n别存放 在32位寄存器f\n1\n和f\n2\n中，若(f\n1\n)=CC90 0000H，\n(f\n2\n)=B0C0 0000H，则x和y之间的\n关系为 。","options":[{"key":"A","text":"x<y且符号相同"},{"key":"B","text":"x<y且符号不同"},{"key":"C","text":"x>y且符号相同"},{"key":"D","text":"x>y且符号不同"}],"hasFigure":false,"source":"curated"},{"number":15,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某容量为256MB的存储器由若干4M×8位的DRAM芯片构成，该DRAM芯片的\n地址引脚和数据引脚总数是 。","options":[{"key":"A","text":"19"},{"key":"B","text":"22"},{"key":"C","text":"30"},{"key":"D","text":"36"}],"hasFigure":false,"source":"curated"},{"number":16,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"采用指令Cache与数据Cache分离的主要目的是 。","options":[{"key":"A","text":"降低Cache的缺失损失"},{"key":"B","text":"提高Cache的命中率"},{"key":"C","text":"降低CPU平均访 存时间"},{"key":"D","text":"减少指令流水线资源冲突"}],"hasFigure":false,"source":"curated"},{"number":17,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机有16个通用寄 存器，采用32位定长指令字，操作码字段（含寻址方式位）\n为8位，Store指令的源操作数和目的操作数分别采用寄存器直接寻址和基址寻址方式。若\n基址寄存器可使用任一通用寄存器，且偏移量用补码表示，则Store指令中偏移量的取值范\n围是\n 。","options":[{"key":"A","text":"-32768 ~ +32767"},{"key":"B","text":"-32767 ~ +32768"},{"key":"C","text":"-65536 ~ +65535"},{"key":"D","text":"-65535 ~ +65536"}],"hasFigure":false,"source":"curated"},{"number":18,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机采用微程序控制器，共有32条指令，公共的取指令微程序包 含2条微指\n令，各指令对应的微程序平均由4条微指令组成，采用断定法（下地址字段法）确定下条微\n\n指令地址，则微指令中下址字段的位数至少是 。","options":[{"key":"A","text":"5"},{"key":"B","text":"6"},{"key":"C","text":"8"},{"key":"D","text":"9"}],"hasFigure":false,"source":"curated"},{"number":19,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某同步总线采用数据线和地址线复用方式，其中地址/数据线有32根，总线时钟频\n率为66MHz，每个时钟周期传送两次数据(上升沿和下降沿各传送一次数据)，该总线的最大\n数据传输率(总线带宽)是\n 。","options":[{"key":"A","text":"132 MB/s"},{"key":"B","text":"264 MB/s"},{"key":"C","text":"528 MB/s"},{"key":"D","text":"1056 MB/s"}],"hasFigure":false,"source":"curated"},{"number":20,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"一次总线事务中，主设备只需给出一个首地址，从设备就能从首地址开始的若干连\n续单元读出或写入多个数据。这种总线事务方式称为 。","options":[{"key":"A","text":"并行传输"},{"key":"B","text":"串行传输"},{"key":"C","text":"突发传输"},{"key":"D","text":"同步传输"}],"hasFigure":false,"source":"curated"},{"number":21,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列有关I/O接口的叙述中，错误\n．．\n的是。","options":[{"key":"A","text":"状态端口和控制端口可以合用同一个寄存器"},{"key":"B","text":"I/O接口中CPU可访问的寄存器称为I/O端口"},{"key":"C","text":"采用独立编址方式时，I/O端口地址和主存地址可能相同"},{"key":"D","text":"采用统一编址方式时，CPU不能用访存指令访问I/O端口"}],"hasFigure":false,"source":"curated"},{"number":22,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"若某设备中断请求的响应和处理时间为100ns，每400ns发出一次中断请求，中断\n响应所 允许的最长延迟时间为50ns，则在该设备持续工作过程中，CPU用于该设备的I/O\n时间占整个CPU时间的百分比至少是 。","options":[{"key":"A","text":"12.5%"},{"key":"B","text":"25%"},{"key":"C","text":"37.5%"},{"key":"D","text":"50%"}],"hasFigure":false,"source":"curated"},{"number":23,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列调度算法中，不可能导致饥饿现象的是 。","options":[{"key":"A","text":"时间片轮转"},{"key":"B","text":"静态优先数调度"},{"key":"C","text":"非抢占式短作业优先"},{"key":"D","text":"抢占式短作业优先"}],"hasFigure":false,"source":"curated"},{"number":24,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某系统有n台互斥使用的同类设备，三个并发进程分别需要3、4、5台设备，可确\n保系统不\n．\n发生\n．．\n死锁的设备数n最小为。","options":[{"key":"A","text":"9"},{"key":"B","text":"10"},{"key":"C","text":"11"},{"key":"D","text":"12"}],"hasFigure":false,"source":"curated"},{"number":25,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列指令中，不能\n．\n．\n在用户态执行的是\n。","options":[{"key":"A","text":"trap指令"},{"key":"B","text":"跳转指令"},{"key":"C","text":"压栈指令"},{"key":"D","text":"关中断指令"}],"hasFigure":false,"source":"curated"},{"number":26,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"一个进程 的读磁盘操作完成后，操作系统针对该进程必做的是 。","options":[{"key":"A","text":"修改进程状态为就绪态"},{"key":"B","text":"降低进程优先级"},{"key":"C","text":"给进程分配用户内存空间"},{"key":"D","text":"增加进程时间片大小"}],"hasFigure":false,"source":"curated"},{"number":27,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"现有一个容量为10GB的磁盘分区，磁盘空间以簇(Cluster)为单位进行分配，簇的\n大小为4KB，若采用位图法管理该分区的空闲空间，即用一位(bit)标识一个簇是否被分配，\n则存放该位图所需簇的个数为 。","options":[{"key":"A","text":"80"},{"key":"B","text":"320"},{"key":"C","text":"80K"},{"key":"D","text":"320K"}],"hasFigure":true,"source":"curated"},{"number":28,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列措施中，能加快虚实地址转换的是 。\nI．增大快表(TLB)容量 II．让页表常驻内存 III．增大交换区(swap)","options":[{"key":"A","text":"仅I"},{"key":"B","text":"仅II"},{"key":"C","text":"仅I、II"},{"key":"D","text":"仅II、III"}],"hasFigure":false,"source":"curated"},{"number":29,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"在一个文件被用户进程首次打开的过程中，操作系统需做的是 。","options":[{"key":"A","text":"将文件内容读到内存中"},{"key":"B","text":"将文件控制块读到内存中"},{"key":"C","text":"修改文件控制块中的读写权限"},{"key":"D","text":"将文件的数据缓冲区首指针返回给用户进程"}],"hasFigure":false,"source":"curated"},{"number":30,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"在页式 虚拟存储管理系统中，采用某些页面置换算法，会出现Belady异常现象，\n即进程的缺页次数会随着分配给该进程的页框个数的增加而增加。下列算法中，可能出现\nBelady异常现象的是\n 。\n\nI．LRU算法 II．FIFO算法 III．OPT算法","options":[{"key":"A","text":"仅II"},{"key":"B","text":"仅I、II"},{"key":"C","text":"仅I、III"},{"key":"D","text":"仅II、III"}],"hasFigure":false,"source":"curated"},{"number":31,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列关于管道(Pipe)通信的叙述中，正确\n．．\n的是。","options":[{"key":"A","text":"一个管道可实现双向数据传输"},{"key":"B","text":"管道的容量仅受磁盘容量大小限制"},{"key":"C","text":"进程对管道进行读操作和写操作都可能被阻塞"},{"key":"D","text":"一个管道只能有一个读进程或一个写进程对其操作"}],"hasFigure":false,"source":"curated"},{"number":32,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列选项中，属于多级页表优点的是 。","options":[{"key":"A","text":"加快地址变换速度"},{"key":"B","text":"减少缺页中断次数"},{"key":"C","text":"减少页表项所占字节数"},{"key":"D","text":"减少页表所占的连续内存空间"}],"hasFigure":false,"source":"curated"},{"number":33,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"在OSI参考模型中，直接为会话层提供服务的是 。","options":[{"key":"A","text":"应用层"},{"key":"B","text":"表示层"},{"key":"C","text":"传输层"},{"key":"D","text":"网络层"}],"hasFigure":false,"source":"curated"},{"number":34,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"某以太网拓扑及交换机当前转发表如下图所示，主机00-e1-d5-00-23-a1向主机\n00-e1-d\n5-00-23-c1发送1个数据帧，主机00-e1-d5-00-23-c1收到该帧后，向主机\n00-e1-d5-00-23-a1发送1个确认帧，交换机对这两个帧的转发端口分别是（ ）。","options":[{"key":"A","text":"{3}和{1}"},{"key":"B","text":"{2,3}和{1}"},{"key":"C","text":"{2,3}和{1,2}"},{"key":"D","text":"{1,2,3}和{1}"}],"hasFigure":true,"source":"curated"},{"number":35,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下列因素中，不会影响信道数据传输速率的是 。","options":[{"key":"A","text":"信噪比"},{"key":"B","text":"频率宽带"},{"key":"C","text":"调制速率"},{"key":"D","text":"信号传播速度"}],"hasFigure":false,"source":"curated"},{"number":36,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"主机甲与主机乙之间使用后退N帧协议(GBN)传输数据，甲的发送窗口尺寸为1000，\n数据帧长为1000字节，信道带宽为100Mbps，乙每收到一个数据帧立即利用一个短帧(忽略\n其传输延迟)进行确认，若甲乙之间的单向传播延迟是50ms，则甲可以达到的最大平均数据\n传输速率约为\n 。","options":[{"key":"A","text":"10Mbps"},{"key":"B","text":"20Mbps"},{"key":"C","text":"80Mbps"},{"key":"D","text":"100Mbps"}],"hasFigure":false,"source":"curated"},{"number":37,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"站点","options":[{"key":"A","text":""},{"key":"B","text":"C通过CDMA共享链路，A、B、C的码片序列(chipping sequence)分\n别是(1,1,1,1)、\n(1,-1,1,-1)和(1,1,-1,-1)。若C从链路 上收到的序列是(2,0,2,0,0,-2,0,-2,0,2,0,2)，\n则C收到A发送的数据是 。\nA．000 B．\n101"},{"key":"C","text":"110"},{"key":"D","text":"111"}],"hasFigure":false,"source":"curated"},{"number":38,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"主机甲和 主机乙已建立 了TCP连接，甲始终以MSS=1KB大小的段发送数据，并\n一直有数据发送；乙每收到一个数据段都会发出一个接收窗口为10KB的确认段。若甲在t\n时刻发生超时时拥塞窗口为8KB，则从t时刻起，不再发生超时的情况下，经过10个RTT\n后，甲的发送窗口是\n 。","options":[{"key":"A","text":"10K"},{"key":"B","text":"B．12KB"},{"key":"C","text":"14KB"},{"key":"D","text":"15KB"}],"hasFigure":false,"source":"curated"},{"number":39,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下列关于UDP协议的叙述中，正确\n．．\n的是。\nI．提供无连接服务\nII．提供复用/分用服务\nIII．通过差错校验，保障可靠数据传输","options":[{"key":"A","text":"仅I"},{"key":"B","text":"仅I、II"},{"key":"C","text":"仅II、III"},{"key":"D","text":"I、II、III"}],"hasFigure":false,"source":"curated"},{"number":40,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"使用浏览器访问某大学Web网站主页时，不可能\n．．\n．\n使用到\n的协议是。","options":[{"key":"A","text":"PPP"},{"key":"B","text":"ARP"},{"key":"C","text":"UDP"},{"key":"D","text":"SMTP"}],"hasFigure":false,"source":"curated"},{"number":41,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":13,"stem":"(13分)二叉树的带权路径长度(WPL)是二叉树中所有叶结点的带权路径长度之和。给\n定一棵 二叉树T，采用二叉链表存储，结点结构为：\n其中叶结点的weight域保存该结点的非负权值。设root为指向T的根结点 的指针，请\n设计求T的WPL的算法，要求：\n1\n）给出算法的基本设计思想；\n2）使用C或C++语言，给出二叉树结点的数据类型定义；\n3）根据设计思想，采用C或C++语言描述算法，关键之处给出注释。","options":[],"hasFigure":false,"source":"curated"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":10,"stem":"(10分)某网络中的路由器运行OSPF路由协议，题42表是路由器R1维护的主要链\n路状态信息(LSI)，题42图是根据题42表及R1的接口名构造出来的网络拓扑。\n题42表 R1所维护的LSI\nR1的LSI R2的LSI R3的LSI R4的LSI 备 注\nRouter ID 10.1.1.1 10.1.1.2 10.1.1.5 10.1.1.6 标识路由器的IP地址\nLink1\nID 10.1.1.2 10.1.1.1 10.1.1.6 10.1.1.5 所连路由器的Router ID\nIP 10.1.1.1 10.1.1.2 10.1.1.5 10.1.1.6 Link1的本地IP地址\nMetric 3 3 6 6 Link1的费用\nLink2\nID 10.1.1.5 10.1.1.6 10.1.1.1 10.1.1.2 所连路由器的Router ID\nIP 10.1.1.9 10.1.1.13 10.1.1.10 10.1.1.14 Link2的本地IP地址\nMetric 2 4 2 4 Link2的费用\nNet1\nPrefix 192.1.1.0/24 192.1.6.0/24 192.1.5.0/24 192.1.7.0/24 直连网络Net1的网络前缀\nMetric 1 1 1 1 到达直连网络Net1的费用\n题42图 R1构造的网络拓扑\n请回答下列问题。\n1）本题中的网络可抽象为数据结构中的哪种逻辑结构？\n2）针对题42表中的内容，设计合理的链式存储结构，以保存题42表中的链路状态信\n息(LSI)。要求给出链式存储结构的数据类型定义，并画出对应题42表的链式存储结构示意\n图(示意图中可仅以ID标识结点)。\n3\n）按照迪杰斯特拉(Dijikstra)算法的策略，依次给出R1到达题42图中子网192.1.x.x\n的最短路径及费用。","options":[],"hasFigure":true,"source":"curated"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":9,"stem":"（9分）请根据题42描述的网络，继续回答下列问题。\n1\n）假设路由表结构如下表所示，请给出题42图中R1的路由表，要求包括到达题42\nleft weight right\n\n图中子网192.1.x.x的路由，且路由表中的路由项尽可能少。\n2）当主机192.1.1.130向主机192.1.7.211发送一个TTL=64的IP分组时，R1通过哪个\n接口转发该IP分组？主机192.1.7.211收到的IP分组TTL是多少？\n3）若R1增加一条Metric为10的链路连接Internet，则题42表中R1的LSI需要增加\n哪些信息？","options":[],"hasFigure":true,"source":"curated"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":12,"stem":"（12分）某程序中有如下循环代码段p：:”for(int i = 0; i < N; i++) sum+=A[i];”。假\n设编译时变量sum和i分别分配在寄存器R1和R2中。常量N在寄存器R6中，数组A的\n首地址在寄存器R3中。程序段P起始地址为0804 8100H，对应的汇编代码和机器代码如下\n表所示 。\n编号 地址 机器代码 汇编代码 注释\n1 08048100H 00022080H loop: sll R4,R2,2\n(R2)<<2  R4\n2 08048104H 00083020H add R4,R4,R3\n(R4)+(R3)  R4\n3 08048108H 8C850000H load R5,0(R4)\n((R4)+0)  R5\n4 0804810CH 00250820H add R1,R1,R5\n(R1)+(R5)  R1\n5 08048110H 20420001H add R2,R2,1\n(R2)+1  R2\n6 08048114H 1446FFFAH bne R2,R6,loop if(R2)!=(R6) goto loop\n执行上述代码的计算机M采用32位定长指令字，其中分支指令bne采用如下格式：\n31 26 25 21 20 16 15 0\nOP Rs Rd OFFSET\nOP为操作码;；Rs和Rd为寄存器编号；OFFSET为偏移量，用补码表示。请回答下列\n问题，并说明理由。\n1）M的存储器编址单位是什么？\n2\n）已知sll指令实现左移功能，数组A中每个元素占多少位？\n3）题44表中bne指令的OFFSET字段的值是多少？已知bne指令采用相对寻址方式，\n当前PC内容为bne指令地址，通过分析题44表中指令地址和bne指令内容，推断出bne\n指令的转移目标地址计算公式。\n4\n）若M采用如下“按序发射、按序完成”的5级指令流水线：IF（取值）、ID（译码\n及取数）、EXE（执行）、MEM（访存）、WB（写回寄存器），且硬件不采取任何转发措施，\n分支指令 的执行均引起3个时钟周期的\n阻塞，则P中哪些指令的执行会由于数据相关而发\n生流水线阻塞？哪条指令的执行会发生控制冒险？为什么指令1的执行不会因为与指令5\n的数据相关而发生阻塞？","options":[],"hasFigure":false,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"假设对于44题中的计算机M和程序P的机器代码，M采用页式虚拟存储管理；P\n开始执行时，(R1)=(R2)=0，(R6)=1000，其机器代码已调入主存但不在Cache中；数组A未\n调入主存，且所有\n数组元素在同一页，并存储在磁盘同一个扇区。请回答下列问题并说明理\n由。\n1）P执行结束时，R2的内容是多少？\n2）M的指令Cache和数据Cache分离。若指令Cache共有16行，Cache和主存交换的\n块大小为32字节，则其数据区的容量是多少？若仅考虑程序段\nP的执行，则指令Cache的\n命中率为多少？\n3\n）P在执行过程中，哪条指令的执行可能发生溢出异常？哪条指令的执行可能产生缺\n页异常？对于数组A的访问，需要读磁盘和TLB至少各多少次？\n目的网络 下一条 接口","options":[],"hasFigure":false,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"文件F由200条记录组成，记录从1开始编号 。用户打开文件后，欲将内存中的一\n条记录插入到文件F中，作为其第30条记录 。请回答下列问题，并说明理由。\n1）若文件系统采用连续 分配方式，每个磁盘块存放一条记录，文件F存储区域前后均\n有足够的\n空闲磁盘空间，则完成上述插入操作最少 需要访问多少次磁盘 块？F的文件控制块\n内容会发生哪些改变？\n2）若文件系统采用链接分配方式，每个磁盘块存放一条记录和一个链接指针，则完成\n上述插入 操作需要访问多少 次磁盘块？若每个存储块大小为1KB，其中4个字节存放链接\n指针，则该文件系统支持的文件最大长度是多少？","options":[],"hasFigure":false,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":8,"stem":"系统中有 多个生产者进程和多个消费者进程，共享一个能存放1000件产品的环形\n缓冲区（初始为空）。当缓冲区未满时，生产者进程可以放入其生产的一件产品，否则等待；\n当缓冲区未空时，消费者进程可以从缓冲区 取走一件产品，否则等待。要求一个消费者进程\n从缓冲区连续取出10件产品后，其他消费者进程才可以取产品。请使用信号量P，V(wait()，\nsignal())操作实现进程间的互斥与同步，要求写出完整的过程，并说明所用信号量的含义和\n初值。\n\n2014年计算机学科专业基础综合试题","options":[],"hasFigure":false,"source":"curated"}]},{"year":2015,"title":"2015年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知程序如下：\nint S(int n)\n{ return (n<=0)?0:s(n-1)+n;}\nvoid main()\n{ cout<< S(1);}\n程序运行时使用栈来保存调用过程的信息，自栈底到栈顶保存的信息依次对应的是 。\nA．main()→S(1)→S(0) B．S(0)→S(1)→main()\nB．main()→S(0)→S(1) D．S(1)→S(0)→main()","options":[{"key":"A","text":"选项 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。","options":[{"key":"A","text":"根结点的度一定为2"},{"key":"B","text":"树中最小元素一定是叶结点"},{"key":"C","text":"最后插入的元素一定是叶结点"},{"key":"D","text":"树中最大元素一定是无左子树"}],"hasFigure":false,"source":"curated"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"设有向图G=(V,E)，顶点集V={V\n0\n,V\n1\n,V\n2\n,V\n3\n}，边集E={<v\n0\n,v\n1\n>，<v\n0\n,v\n2\n>，<v\n0\n,v\n3\n>，<v\n1\n,v\n3\n>}。若\n从顶点V\n0\n开始对图进行深度优先遍历，则可能得到的不同遍历序列个数是 。","options":[{"key":"A","text":"2"},{"key":"B","text":"3"},{"key":"C","text":"4"},{"key":"D","text":"5"}],"hasFigure":true,"source":"curated"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"求下面带权图的最小（代价）生成树时，可能是克鲁斯卡（Kruskal）算法第2次选中但不是普\n里姆（Prim）算法（从V\n4\n开始）第2次选中的边是 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4GB，字长为32位，按字节编址，采用32位字长指令字格式。\n若指令按字边界对齐存放，则程序计数器（PC）和指令寄存器（IR）的位数至少分别是","options":[{"key":"A","text":"30、30"},{"key":"B","text":"30、32"},{"key":"C","text":"32、30"},{"key":"D","text":"32、32"}],"hasFigure":false,"source":"ocr"},{"number":19,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"在无转发机制的五段基本流水线（取指、译码/读寄存器、运算、访写回寄存器）中，\n下列指令序列存在数据冒险的指令对是\nI1: add R1, R2,R3; (R2)+ (R3)→R1\nI2: add R5,R2,R4; (R2) + (R4)→R5\n13: add\n1R4,R5,R3; (R5) + (R3)→R4\nI4: add R5,R2,R6; (R2)+ 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R2。若系统出现死\n锁，则处于死锁状态的进程数至少是","options":[{"key":"A","text":"1"},{"key":"B","text":"2"},{"key":"C","text":"3"},{"key":"D","text":"4"}],"hasFigure":false,"source":"ocr"},{"number":26,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某系统采用改进型CLOCK置换算法，页表项中字段A为访问位，M为修改位。A=0\n表示页最近没有被访问，A=1表示页最近被访问过。M=0表示页没有被修改过，M=1表示\n页被修改过。按(A,M)所有可能的取值，将页分为四类：(0,0),(1,0),(0,1)和(1,1)，则该算法淘\n汰页的次序为","options":[{"key":"A","text":"(0, 0), (0, 1), (1, 0), (1, 1)"},{"key":"B","text":"(0, 0), (1,0), (0, 1), (1, 1)"},{"key":"C","text":"(0, 0), (0, 1), (1, 1), (1, 0)"},{"key":"D","text":"(0, 0), (1, 1), (0, 1), (1,0)"}],"hasFigure":false,"source":"ocr"},{"number":27,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"使用TSL（Test and SetLock）指令实现进程互斥的伪代码如下所示。\ndo{\nwhile(TSL(&lock)）;\ncritical section;\nlock=FALSE;\n}while(TRUE);\n下列与该实现机制相关的叙述中，正确的是","options":[{"key":"A","text":"退出临界区的进程负责唤醒阻塞态进程"},{"key":"B","text":"等待进入临界区的进程不会主动放弃CPU"},{"key":"C","text":"上述伪代码满足“让权等待”的同步准则"},{"key":"D","text":"while(TSL(&lock))语句应在关中断状态下执行"}],"hasFigure":false,"source":"ocr"},{"number":28,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某进程的段表内容如下所示。\n各甜\n段长\n内存起始地址\n权限\n状态\n0\n100\n6000\n只读\n在内存\n1\n200\n...\n读写\n不在内存\n2\n300\n4000\n读写\n在内存\n当访问段号为2、段内地址为400的逻辑地址时，进行地址转换的结果是","options":[{"key":"A","text":"段缺失异常"},{"key":"B","text":"得到内存地址4400"},{"key":"C","text":"越权异常"},{"key":"D","text":"越界异常"}],"hasFigure":false,"source":"ocr"},{"number":29,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某进程访问页面的序列如下所示。\n,1,3,4,5,6,0,3,2,3,2,A0,4,0,3,2,9,2,1，··\n时间\n若工作集的窗口大小为6，则在时刻的工作集为","options":[{"key":"A","text":"{6, 0, 3,2}"},{"key":"B","text":"{2,3,0,4}"},{"key":"C","text":"{0, 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SPOOLing技术的叙述中，错误的是","options":[{"key":"A","text":"需要外存的支持"},{"key":"B","text":"需要多道程序设计技术的支持"},{"key":"C","text":"可以让多个作业共享一台独占设备"},{"key":"D","text":"E\n由用户作业控制设备与输入/输出井之间的数据传送"}],"hasFigure":false,"source":"ocr"},{"number":32,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列关于管程的叙述中，错误的是","options":[{"key":"A","text":"管程只能用于实现进程的互斥"},{"key":"B","text":"管程是由编程语言支持的进程同步机制"},{"key":"C","text":"任何时候只能有一个进程在管程中执行"},{"key":"D","text":"管程中定义的变量只能被管程内的过程访问\n题33~41均依据题33~41图回签。"}],"hasFigure":false,"source":"ocr"},{"number":33,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"在OSI参考模型中，R1、Switch、Hub实现的最高功能层分别是","options":[{"key":"A","text":"2、2、1"},{"key":"B","text":"2、2、2"},{"key":"C","text":"3、2、1"},{"key":"D","text":"3、2、2"}],"hasFigure":false,"source":"ocr"},{"number":34,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若连接R2和R3链路的频率带宽为8kHz，信噪比为30dB，该链路实际数据传输速率\n约为理论最大数据传输速率的50%，则该链路的实际数据传输速率约是","options":[{"key":"A","text":"8kbps"},{"key":"B","text":"20kbps"},{"key":"C","text":"40kbps"},{"key":"D","text":"80kbps\n图中：\nR1~R3为路由器；\nSwitch为100Base-T交换机；\n201.1.3.9\nHub为100Base-T集线器；\n主机H1~H4的默认域名服务\n器均配置为201.1.1:1。\nNATLO\nEOLI\n201.1.3.1\n20\nR3\nE1192.168.3.254\nSwitch\nHub\nH4\n192.168.3.252\nDNS服务器\n201.1.1.1\n192.168.3.251\n192.168.3.2\n192.168.3.3\n题33~41图\n除H4外，从物理层上能够收到该确认帧的主机还有\n°"}],"hasFigure":false,"source":"ocr"},{"number":35,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"主机 H1 向 H3 发送数据帧，H3 返回确认帧。除 H4 外，从物理层上能够收到该确认帧的主机还有（ ）。","options":[{"key":"A","text":"仅 H2"},{"key":"B","text":"仅 H3"},{"key":"C","text":"仅 H1、H2"},{"key":"D","text":"仅 H2、H3"}],"hasFigure":false,"source":"manual"},{"number":36,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若Hub再生比特流过程中，会产生1.535us 延时，信号传播速度为200m/us，不考虑\n以太网帧的前导码，则H3与H4之间理论上可以相距的最远距离是","options":[{"key":"A","text":"200m"},{"key":"B","text":"205m"},{"key":"C","text":"359m"},{"key":"D","text":"512m"}],"hasFigure":false,"source":"ocr"},{"number":37,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"假设R1、R2、R3采用RIP协议交换路由信息，且均已收敛。若R3检测到网络201.1.2.0/25\n不可达，并向R2通告一次新的距离向量，则R2更新后，其到达该网络的距离是","options":[{"key":"A","text":"2"},{"key":"B","text":"3"},{"key":"C","text":"16"},{"key":"D","text":"17"}],"hasFigure":false,"source":"ocr"},{"number":38,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"假设连接R1、R2和R3之间的点对点链路使用 201.1.3.x/30地址，当H3访问Web服\n务器S时，R2转发出去的封装 HTTP请求报文的IP分组的源IP 地址和目的IP 地址分别\n是","options":[{"key":"A","text":"192.168.3.251, 130.18.10.1"},{"key":"B","text":"192.168.3.251,201.1.3.9"},{"key":"C","text":"201.1.3.8, 130.18.10.1"},{"key":"D","text":"201.1.3.10, 130.18.10.1"}],"hasFigure":false,"source":"ocr"},{"number":39,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若H1与H2的默认网关和子网掩码均分别配置为192.168.3.1和255.255.255.128，H3\n和H4的默认网关和子网掩码均分别配置为192.168.3.254和255.255.255.128，则下列现象中可\n能发生的是","options":[{"key":"A","text":"H1不能与H2进行正常IP通信"},{"key":"B","text":"H2 与 H4 均不能访问 Internet"},{"key":"C","text":"H1不能与H3进行正常IP通信"},{"key":"D","text":"H3不能与H4进行正常IP通信"}],"hasFigure":false,"source":"ocr"},{"number":40,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"假设所有域名服务器均采用迭代查询方式进行域名解析。当H4访问规范域名为\nwww.abc.xyz.com的网站时，域名服务器201.1.1.1在完成该域名解析过程中，可能发出DNS查\n询的最少和最多次数分别是","options":[{"key":"A","text":"0,3"},{"key":"B","text":"1,3"},{"key":"C","text":"0,4"},{"key":"D","text":"1,4\n二、综合应用题（第41～47小题，共70分）"}],"hasFigure":false,"source":"ocr"},{"number":41,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"假设题33～41图中的H3访问Web服务器S时，S为新建的TCP连接分配了20KB\n（K=1024）的接收缓存，最大段长MSS=1KB，平均往返时间RTT.=200ms。H3建立连接时\n的初始序号为100，且持续以MSS大小的段向S发送数据，拥塞窗口初始阈值为32KB；S对\n收到的每个段进行确认，并通告新的接收窗口。假定TCP连接建立完成后，S端的TCP接收缓\n存仅有数据存入而无数据取出。请回答下列问题。\n（1）在TCP连接建立过程中，H3收到的S发送过来的第二次握手TCP段的SYN和ACK\n标志位的值分别是多少？确认序号是多少？\n的发送窗口变为多少？\n（3）当H3的发送窗口等于0时，下一个待发送的数据段序号是多少？H3从发送第1个数\n（4）若H3与S之间通信已经结束，在t时刻H3请求断开该连接，则从t时刻起，S释放\n该连接的最短时间是多少？\n请回答下列问题并给出推导过程。\n（1）若T有m个非叶结点，则T中的叶结点有多少个？\n（2）若T的高度为h（单结点的树h=1)，则T的结点数最多为多少个？最少为多少个？","options":[],"hasFigure":true,"source":"ocr"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"设 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完\n工作\n完\n外设D\n成\n成\nCPU\n启！\n启！\n动\nY\n动\nY\n启\n请响“返\n请响”返\n请响\n动\n求应回\n求应回\n求应\nI/O端口每收到一个字符申请一次中断，中断响应需10个时钟周期，中断服务程序共有20\n条指令，其中第15条指令启动D工作。若CPU需从D读取1000个字符，则完成这一任务所\n响应阶段CPU进行了哪些操作？","options":[],"hasFigure":true,"source":"ocr"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"某计算机采用页式虚拟存储管理方式，按字节编址，虚拟地址为32位，物理地址为\n24位，页大小为8KB；TLB采用全相联映射；Cache数据区大小为64KB，按2路组相联方式\n组织，主存块大小为64B。存储访问过程的示意图如下。\n虚拟地址\nA\n物理地址\nC\nD\n标记页框号\nE\nF\nG\n比较器\nTLB\n标记\n数据\n标记\n数据\n比较器\nB\n存在位页框号\nCache\nH\n页表\n比较器\n比较器\n请回答下列问题。\n（1）图中字段A～G的位数各是多少？TLB标记字段B中存放的是什么信息？\n（2）将块号为4099的主存块装入到Cache 中时，所映射的Cache 组号是多少？对应的H\n字段内容是什么？\n（3）Cache缺失处理的时间开销大还是缺页处理的时间开销大？为什么？\n（4）为什么Cache可以采用直写（WriteThrough）策略，而修改页面内容时总是采用回写\n（WriteBack）策略。","options":[],"hasFigure":true,"source":"ocr"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"某进程调度程序采用基于优先数（priority）的调度策略，即选择优先数最小的进程运行，\n进程创建时由用户指定一个nice 作为静态优先数。为了动态调整优先数，引入运行时间cpuTime\n和等待时间waitTime，初值均为0。进程处于执行态时，cpuTime定时加1，且waitTime置0；进\n程处于就绪态时，cpuTime置0，waitTime定时加1。请回答下列问题。\n（1）若调度程序只将 nice 的值作为进程的优先数，即 priority=nice，则可能会出现饥饿现\n象，为什么？\n（2）使用nice、cpuTime和waitTime 设计一种动态优先数计算方法，以避免产生饥饿现象，\n并说明waitTime的作用。","options":[],"hasFigure":false,"source":"ocr"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":8,"stem":"某磁盘文件系统使用链接分配方式组织文件，簇大小为4KB。目录文件的每个目录项\n包括文件名和文件的第一个簇号，其他簇号存放在文件分配表FAT中。\n（1）假定目录树如下图所示，各文件占用的簇号及顺序如下表所示，其中dir、dir1是目录，\nfilel、file2是用户文件。请给出所有目录文件的内容。\n文件名\n簇号\nI!\n1\ndirl\n48\nfilel\nfilel\n100、106、108\ni1e2\nfile2\n200、201、202\n（2）若FAT的每个表项仅存放簇号，占2字节，则FAT的最大长度为多少字节？该文件系\n统支持的文件长度最大是多少？\n（3）系统通过目录文件和FAT实现对文件的按名存取，说明file1的106、108两个簇号分\n别存放在FAT的哪个表项中。\n（4）假设仅FAT和dir目录文件已读入内存，若需将文件dir/dir1/file的第5000个字节读\n入内存，则要访问哪几个簇？","options":[],"hasFigure":true,"source":"ocr"}]},{"year":2017,"title":"2017年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列函数的时间复杂度是 。\nint func(int n){\n int i=0, sum=0;\n while(sum < n) sum += ++i;\n return i;\n}","options":[{"key":"A","text":"O(logn)"},{"key":"B","text":"O(n\n1/2\n)"},{"key":"C","text":"O(n)"},{"key":"D","text":"O(nlogn)"}],"hasFigure":false,"source":"curated"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列关于栈的叙述中，错误的是 。\nI．采用非递归方式重写递归程序时必须使用栈\nII．函数调用时，系统要用栈保存必要的信息\nIII．只要确定了入桟次序，即可确定出栈次序\nIV．栈是一种受限的线性表，允许在其两端进行操作","options":[{"key":"A","text":"仅 I"},{"key":"B","text":"仅I、II、III"},{"key":"C","text":"仅I、III、IV"},{"key":"D","text":"仅II、III、IV"}],"hasFigure":false,"source":"curated"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"适用于压缩存储稀疏矩阵的两种存储结构是 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a g b b"},{"key":"C","text":"a f b e a g d"},{"key":"D","text":"a f e e f g d"}],"hasFigure":false,"source":"curated"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知无向图G含有16条边，其中度为4的顶点个数为3，度为3的顶点个数为4，其他顶点的度均小于3。图\nG所含的顶点个数至少是 。","options":[{"key":"A","text":"10"},{"key":"B","text":"11"},{"key":"C","text":"13"},{"key":"D","text":"15"}],"hasFigure":true,"source":"curated"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列二叉树中，可能成为折半查找判定树（不含外部结点）的是 。\n\n王道论坛（www.cskaoyan.com）友情分享！","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":false,"source":"curated"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列应用中，适合使用B+树的是 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GHz。在M1和M2上\n运行某基准程序P，平均CPI分别为2和1，则程序P在M1和M2上运行时间的比值是 。","options":[{"key":"A","text":"0.4"},{"key":"B","text":"0.625"},{"key":"C","text":"1.6"},{"key":"D","text":"2.5"}],"hasFigure":false,"source":"curated"},{"number":13,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机主存按字节编址，由4个64M×8位的DRAM芯片采用交叉编址方式构成，并与宽度为32位的存\n储器总线相连，主存每次最多读写32位数据。若double型变量x的主存地址为804 001AH，则读取x需要的存储周期\n数是 。","options":[{"key":"A","text":"1"},{"key":"B","text":"2"},{"key":"C","text":"3"},{"key":"D","text":"4"}],"hasFigure":false,"source":"curated"},{"number":14,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某C语言程序段如下：\nfor(i=0;i<=9;i++){\ntemp = 1;\nfor(j=0;j<=i;j++) temp *= a[j];\nsum += temp；\n}\n下列关于数组a的访问局部性的描述中，正确的是 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IV．I/O设备利用率高","options":[{"key":"A","text":"仅I、III"},{"key":"B","text":"仅I、IV"},{"key":"C","text":"仅II、III"},{"key":"D","text":"仅I、III、IV"}],"hasFigure":false,"source":"curated"},{"number":29,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列选项中，磁盘逻辑格式化程序所做的工作是 。\nI．对磁盘进行分区\nII．建立文件系统的根目录\nIII．确定磁盘扇区校验码所占位数\nIV．对保存空闲磁盘块信息的数据结构进行初始化","options":[{"key":"A","text":"仅II"},{"key":"B","text":"仅II、IV"},{"key":"C","text":"仅III、IV"},{"key":"D","text":"仅I、II、IV"}],"hasFigure":false,"source":"curated"},{"number":30,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某文件系统中，针对每个文件，用户类别分为4类：安全管理员、文件主、文件主的伙伴、其他用户；访问\n权限分为5种：完全控制、执行、修改、读取、写入。若文件控制块中用二进制位串表示文件权限，为表示不同类别\n用户对一个文件的访问权限，则描述文件权限的位数至少应为 。","options":[{"key":"A","text":"5"},{"key":"B","text":"9"},{"key":"C","text":"12"},{"key":"D","text":"20"}],"hasFigure":false,"source":"curated"},{"number":31,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"若文件f1的硬链接为f2，两个进程分别打开f1和f2，获得对应的文件描述符为fd1和fd2，则下列叙述中，\n正确的是 。\nI．f1和f2的读写指针位置保持相同\nII．f1和f2共享同一个内存索引结点\nIII．fd1和fd2分别指向各自的用户打开文件表中的一项","options":[{"key":"A","text":"仅I"},{"key":"B","text":"仅II、III"},{"key":"C","text":"仅I、II"},{"key":"D","text":"I、II和III"}],"hasFigure":false,"source":"curated"},{"number":32,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"系统将数据从磁盘读到内存的过程包括以下操作：\n①DMA控制器发出中断请求\n②初始化DMA控制器并启动磁盘\n③从磁盘传输一块数据到内存缓冲区\n④执行“DMA结束”中断服务程序\n正确的执行顺序是 。","options":[{"key":"A","text":"③->①->②->④"},{"key":"B","text":"②->③->①->④"},{"key":"C","text":"②->①->③->④"},{"key":"D","text":"①->②->④->③"}],"hasFigure":false,"source":"curated"},{"number":33,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"假设OSI参考模型的应用层欲发送400 B的数据（无拆分），除物理层和应用层之外，其他各层在封装PDU\n时均引人20 B的额外开销，则应用层数据传输效率约为 。","options":[{"key":"A","text":"80%"},{"key":"B","text":"83%"},{"key":"C","text":"87%"},{"key":"D","text":"91%"}],"hasFigure":false,"source":"curated"},{"number":34,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若信道在无噪声情况下的极限数据传输速率不小于信噪比为30dB条件下的极限数据传输速率，则信号状态数\n至少是 。","options":[{"key":"A","text":"4"},{"key":"B","text":"8"},{"key":"C","text":"16"},{"key":"D","text":"32"}],"hasFigure":false,"source":"curated"},{"number":35,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"在下图所示的网络中,若主机H发送一个封装访问Internet的IP分组的IEEE 802.11数据帧F,则帧F的地址1、\n地址2和地址3分别是 。\n\n王道论坛（www.cskaoyan.com）友情分享！","options":[{"key":"A","text":"00-12-34-56-78-9a，00-12-34-56-78-9b，00-12-34-56-78-9c"},{"key":"B","text":"00-12-34-56-78-9b，00-12-34-56-78-9a，00-12-34-56-78-9c"},{"key":"C","text":"00-12-34-56-78-9b，00-12-34-56-78-9c，00-12-34-56-78-9a"},{"key":"D","text":"00-12-34-56-78-9a，00-12-34-56-78-9c，00-12-34-56-78-9b"}],"hasFigure":true,"source":"curated"},{"number":36,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下列IP地址中，只能作为IP分组的源IP地址但不能作为目的IP地址的是 。","options":[{"key":"A","text":"0.0.0.0"},{"key":"B","text":"127.0.0.1"},{"key":"C","text":"200.10.10.3"},{"key":"D","text":"255.255.255.255"}],"hasFigure":false,"source":"curated"},{"number":37,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"直接封装RIP、OSPF、BGP报文的协议分别是 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。","options":[{"key":"A","text":"数据连接在每次数据传输完毕后就关闭"},{"key":"B","text":"控制连接在整个会话期间保持打开状态"},{"key":"C","text":"服务器与客户端的TCP 20端口建立数据连接"},{"key":"D","text":"客户端与服务器的TCP 21端口建立控制连接"}],"hasFigure":false,"source":"curated"},{"number":41,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"(15分）请设计一个算法，将给定的表达式树（二叉树）转换为等价的中缀表达式（通过括号反映操作符的\n计算次序）并输出。例如，当下列两棵表达式树作为算法的输人时：\n\n输出的等价中缀表达式分别为(a+b)*(c*(-d))和(a*b)+(-(c-d))。\n二叉树结点定义如下:\ntypedef struct node{\nchar data[10]; //存储操作数或操作符\nstruct node *left, *right;\n}BTree;\n要求：\n(1)给出算法的基本设计思想。\n(2)根据设计思想，采用C或C++语言描述算法，关键之处给出注释。","options":[],"hasFigure":false,"source":"curated"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":8,"stem":"(8分）使用Prim(普里姆）算法求带权连通图的最小（代价）生成树(MST)。请回答下列问题。\n(1)对下列图G，从顶点A开始求G的MST，依次给出按算法选出的边。\n(2)图G的MST是唯一的吗？\n\n王道论坛（www.cskaoyan.com）友情分享！\n(3)对任意的带权连通图，满足什么条件时，其MST是唯一的？","options":[],"hasFigure":true,"source":"curated"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"(13分）已知，计算f(n)的C语言函数f1如下：\nint f1(unsigned n){\nint sum=1, power=1;\nfor(unsigned i=0;i<=n-1;i++){\n power *= 2;\n sum += power;\n}\nreturn sum;\n}\n将f1中的int都改为float，可得到计算f(n)的另一个函数f2。假设unsigned和int型数据都占32位，float采用IEEE\n754单精度标准。请回答下列问题。\n(1)当n=0时，f1会出现死循环，为什么？若将f1中的变量i和n都定义为int型，则f1是否还会出现死循环？为\n什么？\n(2)f1(23)和f2(23)的返回值是否相等？机器数各是什么（用十六进制表示）？\n(3)f1(24)和f2(24)的返回值分别为33 554 431和33 554 432.0，为什么不相等？\n(4)f(31)=232-1，而f1(31)的返回值却为-1,为什么？若使f1(n)的返回值与f(n)相等，则最大的n是多少？\n(5)f2(127)的机器数为7F80 0000H，对应的值是什么？若使f2(n）的结果不溢出，则最大的n是多少？若使f2(n)\n的结果精确（无舍人），则最大的n是多少？","options":[],"hasFigure":false,"source":"curated"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":10,"stem":"(10分）在按字节编址的计算机M上，题43中f1的部分源程序(阴影部分）与对应的机器级代码（包括指令的\n虚拟地址）如下：\n\n其中，机器级代码行包括行号、虚拟地址、机器指令和汇编指令。请回答下列问题。\n(1)计算机M是RISC还是CISC？为什么？\n\n王道论坛（www.cskaoyan.com）友情分享！\n(2)f1的机器指令代码共占多少字节？要求给出计算过程。\n(3)第20条指令cmp通过i减n-1实现对i和n-1的比较。执行f1(0)过程中当i=0时，cmp指令执行后，进/借位标\n志CF的内容是什么？要求给出计算过程。\n(4)第23条指令shl通过左移操作实现了power *2运算，在f2中能否也用shl指令实现power *2？为什么？","options":[],"hasFigure":false,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":7,"stem":"(7分）假定题44给出的计算机M采用二级分页虚拟存储管理方式，虚拟地址格式如下：\n页目录号（10位） 页表索引（10位） 页内偏移量（12位）\n请针对题43的函数f1和题44中的机器指令代码，回答下列问题。\n(1)函数f1的机器指令代码占多少页？\n(2)取第1条指令（push ebp)时，若在进行地址变换的过程中需要访问内存中的页目录和页表，则会分别访问它们\n各自的第几个表项（编号从0开始）？\n(3)M的I/O采用中断控制方式。若进程P在调用f1之前通过scanf()获取n的值，则在执行scanf()的过程中，进程\nP的状态会如何变化？ CPU是否会进入内核态？","options":[],"hasFigure":false,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"(8分）某进程中有3个并发执行的线程thread1、thread2和thread3，其伪代码如下所示。\n\n请添加必要的信号量和P、V(或wait()、signal())操作，要求确保线程互斥访问临界资源，并且最大程度地并发执行。","options":[],"hasFigure":false,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":9,"stem":"(9分）甲乙双方均采用后退N帧协议（GBN)进行持续的双向数据传输，且双方始终采用捎带确认，帧长均为\n1000 B。S\nx,y\n和R\nx,y\n分别表示甲方和乙方发送的数据帧，其中：x是发送序号；y是确认序号（表示希望接收对方的下一\n帧序号）；数据帧的发送序号和确认序号字段均为3比特。信道传输速率为100Mbps，RTT=0.96ms。下图给出了甲方发\n送数据帧和接收数据帧的两种场景，其中t\n0\n为初始时刻，此时甲方的发送和确认序号均为0，t\n1\n时刻甲方有足够多的数\n据待发送。\n\n王道论坛（www.cskaoyan.com）友情分享！\n\n请回答下列问题。\n(1)对于图(a)，t0时刻到t1时刻期间，甲方可以断定乙方已正确接收的数据帧数是多少？正确接收的是哪儿个帧（请\n用Sx,y形式给出）？\n(2)对于图(a)，从t1时刻起，甲方在不出现超时且未收到乙方新的数据帧之前，最多还可以发送多少个数据帧？其\n中第一个帧和最后一个帧分别是哪个（请用Sx,y形式给出）？\n(3)对于图(b)，从t1时刻起，甲方在不出现新的超时且未收到乙方新的数据帧之前，需要重发多少个数据帧？重发\n的第一个帧是哪个（请用Sx,y形式给出）？\n(4)甲方可以达到的最大信道利用率是多少？\n\n2016年计算机学科专业基础综合试题","options":[],"hasFigure":true,"source":"curated"}]},{"year":2018,"title":"2018年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若栈S\n1\n中保存整数，栈S\n2\n中保存运算符，函数F()依次执行下述各步操作：\n （1）从S\n1\n中依次弹出两个操作数a和b；\n （2）从S\n2\n中弹出一个运算符op；\n （3）执行相应的运算b op a；\n （4）将运算结果压人S\n1\n中。\n假定S\n1\n中的操作数依次是5, 8, 3, 2（2在栈顶），S\n2\n中的运算符依次是*, - , +（+在栈顶）。调\n用3次F()后，S\n1\n栈顶保存的值是 。","options":[{"key":"A","text":"-15"},{"key":"B","text":"15"},{"key":"C","text":"-20"},{"key":"D","text":"20"}],"hasFigure":false,"source":"curated"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"现有队列Q与栈S，初始时Q中的元素依次是1, 2, 3, 4, 5, 6（1在队头），S为空。若仅允\n许下列3种操作：①出队并输出出队元素；②出队并将出队元素人栈；③出栈并输出出栈元素，\n则不能得到的输出序列是 。","options":[{"key":"A","text":"1, 2, 5, 6, 4, 3"},{"key":"B","text":"2, 3, 4, 5, 6, 1"},{"key":"C","text":"3, 4, 5, 6, 1, 2"},{"key":"D","text":"6, 5, 4, 3, 2, 1"}],"hasFigure":false,"source":"curated"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"设有一个12×12的对称矩阵M，将其上三角部分的元素m\ni, j\n（1≤i≤j≤12）按行优先存人C\n语言的一维数组N中，元素m\n6, 6\n在N中的下标是 。","options":[{"key":"A","text":"50"},{"key":"B","text":"51"},{"key":"C","text":"55"},{"key":"D","text":"66"}],"hasFigure":false,"source":"curated"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"设一棵非空完全二叉树T的所有叶结点均位于同一层，且每个非叶结点都有2个子结点。\n若T有k个叶结点，则T的结点总数是 。","options":[{"key":"A","text":"2k-1"},{"key":"B","text":"2k"},{"key":"C","text":"k\n2"},{"key":"D","text":"2\nk\n-1"}],"hasFigure":false,"source":"curated"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知字符集{a, b, c, d, e, f}，若各字符出现的次数分别为6, 3, 8, 2, 10, 4，则对应字符集中\n各字符的哈夫曼编码可能是 。","options":[{"key":"A","text":"00, 1011, 01, 1010, 11, 100"},{"key":"B","text":"00, 100, 110, 000, 0010, 01"},{"key":"C","text":"10, 1011, 11, 0011, 00, 010"},{"key":"D","text":"0011, 10, 11, 0010, 01, 000"}],"hasFigure":false,"source":"curated"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知二叉排序树如下图所示，元素之间应满足的大小关系是 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。","options":[{"key":"A","text":"1.5"},{"key":"B","text":"1.6"},{"key":"C","text":"2"},{"key":"D","text":"3"}],"hasFigure":false,"source":"curated"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对初始数据序列（8, 3, 9, 11, 2, 1, 4, 7, 5, 10, 6）进行希尔排序。若第一趟排序结果为（1,\n3, 7, 5, 2, 6, 4, 9, 11, 10, 8），第二趟排序结果为（1, 2, 6, 4, 3, 7, 5, 8, 11, 10, 9），则两趟排序采用的\n增量（间隔）依次是 。","options":[{"key":"A","text":"3, 1"},{"key":"B","text":"3,2"},{"key":"C","text":"5,2"},{"key":"D","text":"5,3"}],"hasFigure":false,"source":"curated"},{"number":11,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"在将数据序列（6, 1, 5, 9, 8, 4, 7)建成大根堆时，正确的序列变化过程是 。","options":[{"key":"A","text":"6,1,7,9,8,4,5 → 6,9,7,1,8,4,5 → 9,6,7,1,8,4,5 → 9,8,7,1,6,4,5"},{"key":"B","text":"6,9,5,1,8,4,7 → 6,9,7,1,8,4,5 → 9,6,7,1,8,4,5 → 9,8,7,1,6,4,5"},{"key":"C","text":"6,9,5,1,8,4,7 → 9,6,5,1,8,4,7 → 9,6,7,1,8,4,5 → 9,8,7,1,6,4,5"},{"key":"D","text":"6,1,7,9,8,4,5 → 7,1,6,9,8,4,5 → 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（3）Cache采用什么映射方式？若 Cache采用LRU替换算法和回写（Write Back）策略，\n则Cache每行中除数据（Data）、Tag和有效位外，还应有哪些附加位？Cache总容量是多少？Cache\n\n中有效位的作用是什么？\n （4）若CPU给出的虚拟地址为0008 C040H，则对应的物理地址是多少？是否在Cache中命\n中？说明理由，若CPU给出的虚拟地址为0007 C260H，则该地址所在主存块映射到的Cache组\n号是多少？","options":[],"hasFigure":true,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"(8分)请根据题44图给出的虚拟储管理方式，回答下列问题。\n （1）某虚拟地址对应的页目录号为6，在相应的页表中对应的页号为6，页内偏移量为8，\n该虚拟地址的十六进制表示是什么？\n （2）寄存器PDBR用于保存当前进程的页目录起始地址，该地址是物理地址还是虚拟地址？\n进程切换时，PDBR的内容是否会变化？说明理由。同一进程的线程切换时，PDBR的内容是否\n会变化？说明理由。\n （3）为了支持改进型 CLOCK置换算法，需要在页表项中设置哪些字段？","options":[],"hasFigure":true,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":7,"stem":"(7分)某文件系统采用索引节点存放文件的属性和地址信息，簇大小为4KB。每个文件索\n引节点占64B，有11个地址项，其中直接地址项8个，一级、二级和三级间接地址项各1个，每\n个地址项长度为4B。请回答下列问题。\n （1）该文件系统能支持的最大文件长度是多少？（给出计算表达式即可）\n （2）文件系统用1M（1M=2\n20\n）个簇存放文件索引节点，用512M个簇存放文件数据。若一\n个图像文件的大小为5600B，则该文件系统最多能存放多少个这样的图像文件？\n 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磁盘有300个柱面，每个柱面有10个磁道，每个磁道有200\n个扇区，扇区大小为512B。文件系统的每个簇包含2个扇区。请回答下列问题：\n（1）磁盘的容量是多少？\n（2）假设磁头在85号柱面上，此时有4个磁盘访问请求，簇号分别为100260、60005、\n101660和110560。若采用最短寻道时间优先（SSTF）调度算法，则系统访问簇的先后次序是\n什么？\n（3）第100530簇在磁盘上的物理地址是什么？将簇号转换成磁盘物理地址的过程是由I/O\n系统的什么程序完成的？","options":[],"hasFigure":false,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":16,"stem":"（16分）已知\n()!(1)(2)21fnnnnn\n，计算f(n)的C语言函数f1的源程\n序（阴影部分）及其在32位计算机M上的部分机器级代码如下：\nintf1(intn){\n10040100055pushebp\n.........\nif(n>1)\n1100401018837D0801cmpdwordptr[ebp+8],1\n120040101C7E17jlef1+35h(00401035)\nreturnn*f1(n-1);\n130040101E8B4508moveax,dwordptr[ebp+8]\n140040102183E801subeax,1\n150040102450pusheax\n1600401025E8D6FFFFFFcallf1(00401000)\n.........\n19004010300FAFC1imuleax,ecx\n2000401033EB05jmpf1+3Ah(0040103a)\n\n·7·\n2019年全国硕士研究生入学统一考试计算机科学与技术学科联考计算机学科专业基础综合试题\nelsereturn1;\n2100401035B801000000moveax,1\n}\n.........\n26004010403BECcmpebp,esp\n.........\n300040104AC3ret\n其中，机器级代码行包括行号、虚拟地址、机器指令和汇编指令，计算机M按字节编址，int\n型数据占32位。请回答下列问题：\n（1）计算f(10)需要调用函数f1多少次？执行哪条指令会递归调用f1？\n（2）上述代码中，哪条指令是条件转移指令？哪几条指令一定会使程序跳转执行？\n（3）根据第16行的call指令，第17行指令的虚拟地址应是多少？已知第16行的call指令\n采用相对寻址方式，该指令中的偏移量应是多少（给出计算过程）？已知第16行的call指令的\n后4字节为偏移量，M是采用大端方式还是采用小端方式？\n（4）f(13)=6227020800，但f1(13)的返回值为1932053504，为什么两者不相等？要使\nf1(13)能返回正确的结果，应如何修改f1的源程序？\n（5）第19行的imul指令（带符号整数乘）的功能是R[eax]←R[eax]×R[ecx]，当乘法器输\n出的高、低32位乘积之间满足什么条件时，溢出标志OF=1？要使CPU在发生溢出时转异常\n处理，编译器应在imul指令后应加一条什么指令？","options":[],"hasFigure":false,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":7,"stem":"（7分）对于题45，若计算机M的主存地址为32位，釆用分页存储管理方式，页大小\n为4KB，则第1行的push指令和第30行的ret指令是否在同一页中（说明理由）？若指令Cache\n有64行，采用4路组相联映射方式，主存块大小为64B，则32位主存地址中，哪几位表示块\n内地址？哪几位表示Cache组号？哪几位表示标记（tag）信息？读取第16行的call指令时，\n只可能在指令Cache的哪一组中命中（说明理由）？","options":[],"hasFigure":false,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":9,"stem":"（9分）某网络拓扑如题47图所示，其中R为路由器，主机H1～H4的IP地址配置以\n及R的各接口IP地址配置如图中所示。现有若干以太网交换机（无VLAN功能）和路由器两\n类网络互连设备可供选择。\n题\n47\n图\n\n·8·\n请回答下列问题：\n（1）设备1、设备2和设备3分别应选择什么类型的网络设备？\n（2）设备1、设备2和设备3中，哪几个设备的接口需要配置IP地址？为对应的接口配置\n正确的IP地址。\n（3）为确保主机H1～H4能够访问Internet，R需要提供什么服务？\n（4）若主机H3发送一个目的地址为192.168.1.127的IP数据报，网络中哪几个主机会接收\n该数据报？\n2019年计算机学科专业基础综合试题","options":[],"hasFigure":true,"source":"curated"}]},{"year":2020,"title":"2020年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"将一个10 * 10对称矩阵M的上三角部分的元素素푚\n푖푗\n (1≤i≤j≤10) 按列优先存\n入 C 语言的一维数组 N 中，元素푚\n7,2\n在 N 中的下标是：","options":[{"key":"A","text":"15"},{"key":"B","text":"16"},{"key":"C","text":"22"},{"key":"D","text":"23"}],"hasFigure":false,"source":"curated"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对空栈 S 进行Push与Pop操作，入栈序列 a, b, c, d, e 经过Push，Push，Pop，\nPush，Pop，Push，Push，Pop 操作后得到的出栈序列是","options":[{"key":"A","text":"b, a, c"},{"key":"B","text":"b, a, e"},{"key":"C","text":"b, c, a"},{"key":"D","text":"b, c, e"}],"hasFigure":false,"source":"curated"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对于任意一棵高度为 5 且有 10 个节点的二叉树，若采用顺序存储结构保存，每个结\n点占 1 个存储单元（仅存放结点的数据信息），则存放该二叉树需要的存储单元数量\n至少是：","options":[{"key":"A","text":"31"},{"key":"B","text":"16"},{"key":"C","text":"15"},{"key":"D","text":"10\n2020年全国硕士研究生招生考试\n计算机科学与技术学科联考\n计算机学科专业基础综合试题"}],"hasFigure":false,"source":"curated"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知森林 F 及与之对应的二叉树 T，若 F 的先根遍历序列是 a, b, c, d, e, f，中根遍\n历序列是 b, a, d, f, e, c 则 T 的后根遍历序列是：","options":[{"key":"A","text":"b, a, d, f, e, c"},{"key":"B","text":"b, d, f, e, c, a"},{"key":"C","text":"b, f, e, d,\n c, a"},{"key":"D","text":"f, e, d, c, b, a"}],"hasFigure":false,"source":"curated"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列给定的关键字输入序列中，不能生成如下二叉排序树的是：","options":[{"key":"A","text":"4，5，2，1，3"},{"key":"B","text":"4，5，1，2，3"},{"key":"C","text":"4，2，5，3，1"},{"key":"D","text":"4，2，1，3，5"}],"hasFigure":false,"source":"curated"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"修改递归方式实现的图的深度优先搜索（DFS） 算\n法， 将输出（访问）定点信息的语句\n移到退出递归前（即执行输出语句后立刻退出递归）。 采用修改后的算法遍历有向无环\n图G，若输出结果中包含G中的全部顶点，则输出的顶点序列是G的：\nA、 拓扑有序序列\nC、 广度优先搜索序列\nB、 逆拓扑有序序列\nD、 深度优先搜索序列","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":true,"source":"curated"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知无向图G如下所示，使用克鲁斯卡尔（K『uskal）算法求图G的最小生成树，加入\n到最小生成树中的边依次是：\n20","options":[{"key":"A","text":"（b,f)(b,d)(a,e)( c,e )(b,e)"},{"key":"B","text":"（b刀（b,d)(b,e)(a,e)( e,c)\n（不确定最后\n一\n个括号的内容）"},{"key":"C","text":"（a,e)(b,e)( c,e)(b,d)(b\n乃"},{"key":"D","text":"（a,e )( c,e )(b,e )(b,f)(b,d)"}],"hasFigure":true,"source":"curated"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若使\n用 AOE 网估算工程进度，则下列叙述中正确的是：","options":[{"key":"A","text":"关键路径是从原点到汇点边数最多的一条路径"},{"key":"B","text":"关键路径是从原点到汇点路径长度最长的路径"},{"key":"C","text":"增加任一关键活动的时间不会延长工程的工期"},{"key":"D","text":"缩短任一关键活动的时间将会缩短工程的工期"}],"hasFigure":false,"source":"curated"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列关于大根堆（至少含 2 个元素）的叙述中正确的是：\nI．\nII．\nIII．\nIV．\n可以将堆看成一棵完全二叉树\n可采用顺序\n存储方式保存堆；\n可以将堆看成一棵二叉排序树；\n堆中的次大值一定在根的下一层。","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":false,"source":"curated"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"依次将关键字 5，6，9，13，8，2，12，15 插入初始为空的 4 阶 B 树后，根节点中\n包含的关键字是：","options":[{"key":"A","text":"I, II"},{"key":"B","text":"I, II, IV"},{"key":"C","text":"II, III"},{"key":"D","text":"II,\n III, IV\nA、8B、6, 9 C、8, 13 D、9, 12"}],"hasFigure":false,"source":"curated"},{"number":11,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"对大部分元素已有序的数组进行排序时，直接插入排序比简单选择排序效率更高，其原\n因是：\n直接插入排序过程中元素之间的比较次数更少\n直接插入排序过程中所需要的辅助空间更少\n直接插入排序过程中元素的移动次数更少\nI、\nII、\nIII\n、","options":[{"key":"A","text":"I"},{"key":"B","text":"III"},{"key":"C","text":"I,II"},{"key":"D","text":"I,II,III"}],"hasFigure":false,"source":"curated"},{"number":12,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列给出的部件中其位数（宽度）一定与机器字长相同的是：\nI、ALU；II\n、指令寄存器； III、通用寄存器； IV、浮点寄存器","options":[{"key":"A","text":"I, II"},{"key":"B","text":"I, III"},{"key":"C","text":"II, III"},{"key":"D","text":"II, III, IV\n\n14.在按字节编址，采用小端方式的 32 位计算机中，按边界对齐方式为以下 C 语言结构\n型变量 a 分配存储空间。\nStruct record{\nshort x1;\nint x2;\n} a;\n若 a 的首地址为 2020 FE00H，a 的成员变量 x2 的机器数为 1234 0000H，则其中\n34H 所在存储单元的地址是：\nA、2020 FE03H\nB、2020 FE04H C、2020 FE05H D、2020 FE06H\n15.下列关于 TLB 和 Cache 的叙述中错误的是：\nA、命中率与程序局部性有关；\nB\n、缺失后都需要去访问主存；\nC、缺失处理都可以由硬件实现；\nD、都由 DRAM 存储器组成。\n16.某计算机采用 16 位定长指令字格式，操作码位数和寻址方式位数固定，指令系统有\n48条指令，支持直接、\n间接、立即、相对 4 种寻址方式，单地址指令中直接寻址方式\n可寻址范围是：\nA、0~225； B、0~1023； C、-128~127； D、-512~511；"}],"hasFigure":false,"source":"curated"},{"number":13,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"已知带符号整数用补码表示，float型数据用 IEEE 754 标准表示，假定变量 x 的类型只\n能是 int 或 float。当 x 的机器数为\n C800 0000H 时， x 的值可能是：","options":[{"key":"A","text":"-7×2\n27"},{"key":"B","text":"-2\n16"},{"key":"C","text":"2\n17"},{"key":"D","text":"25×2\n27\n17.下列给出的\n处理器类型中理想情况下 CPI 为 1 的是\n ：\nII、多周期 CPU ；\n IV 超标量流水线 CPU\nC、II,IV; D、III,IV；\nI、单周期 CPU；\nIII、基本流水线 CPU；\nA、I，II； B、I,III;\n18.下列关于“自陷”（Trap，也称陷阱）的叙述中错误的是：\nA、自陷是通过陷阱指令预先设定的一类外部中断事件；\nB\n、自陷可用于实现程序调试时的断点设置和单步跟踪；\nC、自陷发生后 CPU 将转去执行操作系统内核相应程序；\nD、自陷处理完成后返回到陷阱指令的下一条指令执行。\n19.QPI 总线是一种点对点全工双周同步串行总线，总线上的设备可同时接收和发送信息，\n每个方向可同时传输 20 位信息（16 位数据+4 位校验位），每个 QPI 数据包有 80 位\n信息，分 2 个时钟周期传送，每个时钟周期传递\n2 次，因此 QPI 总线带宽为每秒传\n送次数*2B*2。若 QPI 时钟频率为\n 2.4GHz，则总线带宽为：\nA、4.8 B、9.6 C、19.2 D、38.4 （单位 GB/s）\n\n22.若设备采用周期挪用 DMA 方式进行输入输出，每次 DMA 传送的数据块大小为 512\n字节，相应的 I/O 接\n 口中有一个 32 位数数据缓冲寄存器，对于数据输入过程，下列叙\n述中错误的是：\nA、每准备好 32 位数据，DMA 控制器就发出一次总线请求；\nB、相对于 CPU，\nDMA 控制器的总线使用权的优先级更高；\nC、在整个数据块的传送过过程中，CPU 不可以访问主存储器；\nD、数据块传送结束时，会产生“DMA 传送结束”的中断请求。\n23.若多个进程共享同一个文件 F，则下列叙述中正确的是：\nA、个进程只能用“读”方式打开文件 F；\nB、在系统打开文件表中仅有一个表项包含 F 的属性；\nC、各进程的用户打开文件表中关于 F 的表项内容相同；\nD、进程关闭 F 时系统删除 F 在系统打开文件表中的表\n项。\n24.下列选项中支持文件长度可变，随机访问的磁盘存储空间分配方式是：\n C、连续分配； D、动态分区分配。 A、索引分配； B、链接分配；\n25.下列与中断相关的操作中，由操作系统完成的是：\nI、保存被中断程序的中断点 II、提供中断服务\n20.下列事件中属于外部中断事件的是：\n I\nII、网络数据包到达 I、访存时缺页； II、定时器延时（不确定） ；\n21.外部中断包\n括不可屏蔽中断（NMI）和可屏蔽中断，下列关于外部中断的叙述中错误的\n是：\nA、CPU 处于关中断状态时也能响应 NMI 请求；\nB、一旦可屏蔽中断请求信号有效，CPU 将立即响应；\nC、不可屏蔽中断的优先级比可屏蔽中断的优先级高；\nD、可通过中断屏蔽字改变可屏蔽中断的处理优先级。\n A、I,II;\nB、I,II,IV; C II,III; D II,III,IV.\nIII、初始化中断向量表 IV、保存中断屏蔽字\n A\n、I,II; B、I,II,IV;\nC III,IV; D II,III,IV.\n26.下列与进程调度有关的因素中在设计多级反馈队列调度算法时需要考虑的是：\nI 就绪队列的数量\nIII 各就绪队列的调度算法\n C、II,III,\nII 就绪队列的优先级\nIV 进程在就绪队列间的迁移条件\nIV; D I,II,III,IV A、I,II; B、III,IV；\n\n27.某系统中有 A,B 两类资源各 6 个，t 时刻资源分配及需求情况如下表所示\n B、存在安全序列 P2,P1,P3;\n D、不存在安全序列。\nt 时刻安全检测结果是：\nA\n、存在安全序列 P1,P2,P3;\nC\n、存在安全序列 P2,P3,P1;\n28.下列因素影响请求分页系统有效（平均）访存时间的是：\nI、 缺页率\n ；\nII、 磁盘读写时间；\nIII、内存访问时间； IV 执行缺页处理程序的 CPU 时间；\nA、II,III B、I,IV C、I\n,III,IV D、I,II,III,IV\n29.下列关于父进程与子进程的叙述中错误的是：\nA、父进程与子进程可以并发执行\nB\n、父进程与子进程共享虚拟地址空间\nC、父进程与子进程有不同的进程控制块\nD、 父进程与子进程不能同时使用同一临界资源\n30.对于具备设备独立性的系统下列叙述中错误的是：\nA、可以使用文件名访问物理设备；\nB、用户程序使用逻辑设备与物理设备之间的映射关系\nD、更换物理设备后必须修改访问该设备的应用程序。（缺一个选项）\n31.某文件系统的目录由文件名和索引节点号构成。若每个目录项长度为 64 字节，其中\n4\n个字节存放索引节点号，60 个字节存放文件名。文件名由小写英文字母构成，则该文\n件系统能创建的文件数量的上限为：\nA、2\n26\n B、2\n32\n C、2\n60\n D、2\n64\n32.下列准则中实现临界区互斥机制必须遵循的是：\nI、 两个进\n 程不能同时进入临界区\nII、 允许进程访问空闲的临界资源\nIII、 进程等待进入临界区的时间是有限的\nIV、 不能进入临界区的执行态进程立即放弃CPU\nD、I,III,IV A、I,IV B、II,III\n C、I,II,III\n\n33.下图描述的协议要素是:\nI、语法 II、语义 III、时序\nA． I\n\nB． II\nC． III\nD．\n I，II，III\n34.下列关于虚电路网络的叙述中错误的是：\nA、可以确保数据分组传输顺序\nB、需要为每条虚电路预分配带宽\nC\n、建立虚电路时需要进行路由选择\nD、依据虚电路号（VCID）进行数据分组转发\n35.下图所示的网络冲突域和广播域的个数分别\n是：\u0001\nA、2，2； B、2，4； C、4，2； D、4，\n4；\n36.假设主机采用停-等协议向主机乙发送数据帧，数据帧长与确认帧长均为1000B。数 据传\n输速率是 10kbps，单项\n传播延时是 200ms。 则甲的最大信道利用率：\nA、80%； B、66.7%； C、44.4%；\n D、40%\n\n37.某 IEEE 802.11 无线局域网中主机 H 与 AP 之间发送或接收 CSMA/CA 帧的过程如\n下图所示，在 H 或 AP 发送帧前所等待的帧间间隔时间（IFS）中最长的是：\nA、IFS1\nB、IF\nS2\nC、\nIFS3\nD、IFS4\n38.若主机甲与主机乙已建立一条 TCP 连接，最大段长（MSS）为 1KB，往返时间（RTT）为\n2ms，则在不出现拥塞的前提下，拥塞窗口从 8kB 增长到 32KB 所需的最长时间是：\nA\n、4ms B、8ms C、24ms D、48ms\n39.若主机甲与主机乙建立 TCP 连接时发送的\n SYN 段中的序号为 1000，在断开连接时，\n甲发送给乙的 FIN 段中的序号为 5001，则在无任何重传的情况下，甲向乙已经发送的应用\n层数据的字节数为：\u0001\n A、\n4002 B、4001 C、4000 D、3999\n40.假设下图所示网络中的本地域名服务器只提供递归查询服务，其他域名的服务器均只提\n供迭代查询服务；局域网内主机访问 Internet 上各服务器的往返时间（RTT）均为10ms，\n忽\n略\n其他各种时延，若主机H 通过 超链接http://www.abc.com/index.html，请求浏览纯\n文本\n Web 页 index.html，则从点击超链接开始到浏览器接收到 index.html 页面为止，\n所需最短、最长时间分别是：\nA、\n10ms，40ms B、10ms,50ms C、20ms,40ms D、20ms,50ms"}],"hasFigure":false,"source":"curated"},{"number":14,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"在按字节编址，采用小端方式的 32 位计算机中，按边界对齐方式为以下 C 语言结构\n型变量 a 分配存储空间。\nStruct record{\nshort x1;\nint x2;\n} a;\n若 a 的首地址为 2020 FE00H，a 的成员变量 x2 的机器数为 1234 0000H，则其中\n34H 所在存储单元的地址是：","options":[{"key":"A","text":"2020 FE03H"},{"key":"B","text":"2020 FE04H"},{"key":"C","text":"2020 FE05H"},{"key":"D","text":"2020 FE06H"}],"hasFigure":false,"source":"curated"},{"number":15,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列关于 TLB 和 Cache 的叙述中错误的是：","options":[{"key":"A","text":"命中率与程序局部性有关；"},{"key":"B","text":"、缺失后都需要去访问主存；"},{"key":"C","text":"缺失处理都可以由硬件实现；"},{"key":"D","text":"都由 DRAM 存储器组成。"}],"hasFigure":false,"source":"curated"},{"number":16,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机采用 16 位定长指令字格式，操作码位数和寻址方式位数固定，指令系统有\n48条指令，支持直接、\n间接、立即、相对 4 种寻址方式，单地址指令中直接寻址方式\n可寻址范围是：","options":[{"key":"A","text":"0~225；"},{"key":"B","text":"0~1023；"},{"key":"C","text":"-128~127；"},{"key":"D","text":"-512~511；\n13.已知带符号整数用补码表示，float型数据用 IEEE 754 标准表示，假定变量 x 的类型只\n能是 int 或 float。当 x 的机器数为\n C800 0000H 时， x 的值可能是：\nA、-7×2\n27\n B、\n-2\n16\n C、2\n17\n D、25×2\n27"}],"hasFigure":false,"source":"curated"},{"number":17,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列给出的\n处理器类型中理想情况下 CPI 为 1 的是\n ：\nII、多周期 CPU ；\n IV 超标量流水线 CPU\nC、II,IV; D、III,IV；\nI、单周期 CPU；\nIII、基本流水线 CPU；\nA、I，II； B、I,III;","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":false,"source":"curated"},{"number":18,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列关于“自陷”（Trap，也称陷阱）的叙述中错误的是：","options":[{"key":"A","text":"自陷是通过陷阱指令预先设定的一类外部中断事件；"},{"key":"B","text":"、自陷可用于实现程序调试时的断点设置和单步跟踪；"},{"key":"C","text":"自陷发生后 CPU 将转去执行操作系统内核相应程序；"},{"key":"D","text":"自陷处理完成后返回到陷阱指令的下一条指令执行。"}],"hasFigure":false,"source":"curated"},{"number":19,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"QPI 总线是一种点对点全工双周同步串行总线，总线上的设备可同时接收和发送信息，\n每个方向可同时传输 20 位信息（16 位数据+4 位校验位），每个 QPI 数据包有 80 位\n信息，分 2 个时钟周期传送，每个时钟周期传递\n2 次，因此 QPI 总线带宽为每秒传\n送次数*2B*2。若 QPI 时钟频率为\n 2.4GHz，则总线带宽为：","options":[{"key":"A","text":"4.8"},{"key":"B","text":"9.6"},{"key":"C","text":"19.2"},{"key":"D","text":"38.4 （单位 GB/s）\n\n22.若设备采用周期挪用 DMA 方式进行输入输出，每次 DMA 传送的数据块大小为 512\n字节，相应的 I/O 接\n 口中有一个 32 位数数据缓冲寄存器，对于数据输入过程，下列叙\n述中错误的是：\nA、每准备好 32 位数据，DMA 控制器就发出一次总线请求；\nB、相对于 CPU，\nDMA 控制器的总线使用权的优先级更高；\nC、在整个数据块的传送过过程中，CPU 不可以访问主存储器；\nD、数据块传送结束时，会产生“DMA 传送结束”的中断请求。\n23.若多个进程共享同一个文件 F，则下列叙述中正确的是：\nA、个进程只能用“读”方式打开文件 F；\nB、在系统打开文件表中仅有一个表项包含 F 的属性；\nC、各进程的用户打开文件表中关于 F 的表项内容相同；\nD、进程关闭 F 时系统删除 F 在系统打开文件表中的表\n项。\n24.下列选项中支持文件长度可变，随机访问的磁盘存储空间分配方式是：\n C、连续分配； D、动态分区分配。 A、索引分配； B、链接分配；\n25.下列与中断相关的操作中，由操作系统完成的是：\nI、保存被中断程序的中断点 II、提供中断服务"}],"hasFigure":false,"source":"curated"},{"number":20,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列事件中属于外部中断事件的是：\n I\nII、网络数据包到达 I、访存时缺页； II、定时器延时（不确定） ；","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":false,"source":"curated"},{"number":21,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"外部中断包\n括不可屏蔽中断（NMI）和可屏蔽中断，下列关于外部中断的叙述中错误的\n是：","options":[{"key":"A","text":"CPU 处于关中断状态时也能响应 NMI 请求；"},{"key":"B","text":"一旦可屏蔽中断请求信号有效，CPU 将立即响应；"},{"key":"C","text":"不可屏蔽中断的优先级比可屏蔽中断的优先级高；"},{"key":"D","text":"可通过中断屏蔽字改变可屏蔽中断的处理优先级。\n A、I,II;\nB、I,II,IV; C II,III; D II,III,IV.\nIII、初始化中断向量表 IV、保存中断屏蔽字\n A\n、I,II; B、I,II,IV;\nC III,IV; D II,III,IV.\n26.下列与进程调度有关的因素中在设计多级反馈队列调度算法时需要考虑的是：\nI 就绪队列的数量\nIII 各就绪队列的调度算法\n C、II,III,\nII 就绪队列的优先级\nIV 进程在就绪队列间的迁移条件\nIV; D I,II,III,IV A、I,II; B、III,IV；\n\n27.某系统中有 A,B 两类资源各 6 个，t 时刻资源分配及需求情况如下表所示\n B、存在安全序列 P2,P1,P3;\n D、不存在安全序列。\nt 时刻安全检测结果是：\nA\n、存在安全序列 P1,P2,P3;\nC\n、存在安全序列 P2,P3,P1;\n28.下列因素影响请求分页系统有效（平均）访存时间的是：\nI、 缺页率\n ；\nII、 磁盘读写时间；\nIII、内存访问时间； IV 执行缺页处理程序的 CPU 时间；\nA、II,III B、I,IV C、I\n,III,IV D、I,II,III,IV\n29.下列关于父进程与子进程的叙述中错误的是：\nA、父进程与子进程可以并发执行\nB\n、父进程与子进程共享虚拟地址空间\nC、父进程与子进程有不同的进程控制块\nD、 父进程与子进程不能同时使用同一临界资源\n30.对于具备设备独立性的系统下列叙述中错误的是：\nA、可以使用文件名访问物理设备；\nB、用户程序使用逻辑设备与物理设备之间的映射关系\nD、更换物理设备后必须修改访问该设备的应用程序。（缺一个选项）\n31.某文件系统的目录由文件名和索引节点号构成。若每个目录项长度为 64 字节，其中\n4\n个字节存放索引节点号，60 个字节存放文件名。文件名由小写英文字母构成，则该文\n件系统能创建的文件数量的上限为：\nA、2\n26\n B、2\n32\n C、2\n60\n D、2\n64\n32.下列准则中实现临界区互斥机制必须遵循的是：\nI、 两个进\n 程不能同时进入临界区\nII、 允许进程访问空闲的临界资源\nIII、 进程等待进入临界区的时间是有限的\nIV、 不能进入临界区的执行态进程立即放弃CPU\nD、I,III,IV A、I,IV B、II,III\n C、I,II,III\n\n33.下图描述的协议要素是:\nI、语法 II、语义 III、时序\nA． I\n\nB． II\nC． III\nD．\n I，II，III\n34.下列关于虚电路网络的叙述中错误的是：\nA、可以确保数据分组传输顺序\nB、需要为每条虚电路预分配带宽\nC\n、建立虚电路时需要进行路由选择\nD、依据虚电路号（VCID）进行数据分组转发\n35.下图所示的网络冲突域和广播域的个数分别\n是：\u0001\nA、2，2； B、2，4； C、4，2； D、4，\n4；\n36.假设主机采用停-等协议向主机乙发送数据帧，数据帧长与确认帧长均为1000B。数 据传\n输速率是 10kbps，单项\n传播延时是 200ms。 则甲的最大信道利用率：\nA、80%； B、66.7%； C、44.4%；\n D、40%\n\n37.某 IEEE 802.11 无线局域网中主机 H 与 AP 之间发送或接收 CSMA/CA 帧的过程如\n下图所示，在 H 或 AP 发送帧前所等待的帧间间隔时间（IFS）中最长的是：\nA、IFS1\nB、IF\nS2\nC、\nIFS3\nD、IFS4\n38.若主机甲与主机乙已建立一条 TCP 连接，最大段长（MSS）为 1KB，往返时间（RTT）为\n2ms，则在不出现拥塞的前提下，拥塞窗口从 8kB 增长到 32KB 所需的最长时间是：\nA\n、4ms B、8ms C、24ms D、48ms\n39.若主机甲与主机乙建立 TCP 连接时发送的\n SYN 段中的序号为 1000，在断开连接时，\n甲发送给乙的 FIN 段中的序号为 5001，则在无任何重传的情况下，甲向乙已经发送的应用\n层数据的字节数为：\u0001\n A、\n4002 B、4001 C、4000 D、3999\n40.假设下图所示网络中的本地域名服务器只提供递归查询服务，其他域名的服务器均只提\n供迭代查询服务；局域网内主机访问 Internet 上各服务器的往返时间（RTT）均为10ms，\n忽\n略\n其他各种时延，若主机H 通过 超链接http://www.abc.com/index.html，请求浏览纯\n文本\n Web 页 index.html，则从点击超链接开始到浏览器接收到 index.html 页面为止，\n所需最短、最长时间分别是：\nA、\n10ms，40ms B、10ms,50ms C、20ms,40ms D、20ms,50ms"}],"hasFigure":false,"source":"curated"},{"number":22,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"若设备采用周期挪用 DM","options":[{"key":"A","text":"方式进行输入输出，每次 DMA 传送的数据块大小为 512\n字节，相应的 I/O 接\n 口中有一个 32 位数数据缓冲寄存器，对于数据输入过程，下列叙\n述中错误的是：\nA、每准备好 32 位数据，DMA 控制器就发出一次总线请求；"},{"key":"B","text":"相对于 CPU，\nDMA 控制器的总线使用权的优先级更高；"},{"key":"C","text":"在整个数据块的传送过过程中，CPU 不可以访问主存储器；"},{"key":"D","text":"数据块传送结束时，会产生“DMA 传送结束”的中断请求。"}],"hasFigure":false,"source":"curated"},{"number":23,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"若多个进程共享同一个文件 F，则下列叙述中正确的是：","options":[{"key":"A","text":"个进程只能用“读”方式打开文件 F；"},{"key":"B","text":"在系统打开文件表中仅有一个表项包含 F 的属性；"},{"key":"C","text":"各进程的用户打开文件表中关于 F 的表项内容相同；"},{"key":"D","text":"进程关闭 F 时系统删除 F 在系统打开文件表中的表\n项。"}],"hasFigure":false,"source":"curated"},{"number":24,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列选项中支持文件长度可变，随机访问的磁盘存储空间分配方式是：\n C、连续分配； D、动态分区分配。 A、索引分配； B、链接分配；","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":false,"source":"curated"},{"number":25,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列与中断相关的操作中，由操作系统完成的是：\nI、保存被中断程序的中断点 II、提供中断服务\n20.下列事件中属于外部中断事件的是：\n I\nII、网络数据包到达 I、访存时缺页； II、定时器延时（不确定） ；\n21.外部中断包\n括不可屏蔽中断（NMI）和可屏蔽中断，下列关于外部中断的叙述中错误的\n是：","options":[{"key":"A","text":"CPU 处于关中断状态时也能响应 NMI 请求；"},{"key":"B","text":"一旦可屏蔽中断请求信号有效，CPU 将立即响应；"},{"key":"C","text":"不可屏蔽中断的优先级比可屏蔽中断的优先级高；"},{"key":"D","text":"可通过中断屏蔽字改变可屏蔽中断的处理优先级。\n A、I,II;\nB、I,II,IV; C II,III; D II,III,IV.\nIII、初始化中断向量表 IV、保存中断屏蔽字\n A\n、I,II; B、I,II,IV;\nC III,IV; D II,III,IV."}],"hasFigure":false,"source":"curated"},{"number":26,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列与进程调度有关的因素中在设计多级反馈队列调度算法时需要考虑的是：\nI 就绪队列的数量\nIII 各就绪队列的调度算法\n C、II,III,\nII 就绪队列的优先级\nIV 进程在就绪队列间的迁移条件\nIV; D I,II,III,IV A、I,II; B、III,IV；","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":false,"source":"curated"},{"number":27,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某系统中有 A,B 两类资源各 6 个，t 时刻资源分配及需求情况如下表所示\n B、存在安全序列 P2,P1,P3;\n D、不存在安全序列。\nt 时刻安全检测结果是：\nA\n、存在安全序列 P1,P2,P3;\nC\n、存在安全序列 P2,P3,P1;","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":true,"source":"curated"},{"number":28,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列因素影响请求分页系统有效（平均）访存时间的是：\nI、 缺页率\n ；\nII、 磁盘读写时间；\nIII、内存访问时间； IV 执行缺页处理程序的 CPU 时间；","options":[{"key":"A","text":"II,III"},{"key":"B","text":"I,IV"},{"key":"C","text":"I\n,III,IV"},{"key":"D","text":"I,II,III,IV"}],"hasFigure":false,"source":"curated"},{"number":29,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列关于父进程与子进程的叙述中错误的是：","options":[{"key":"A","text":"父进程与子进程可以并发执行"},{"key":"B","text":"、父进程与子进程共享虚拟地址空间"},{"key":"C","text":"父进程与子进程有不同的进程控制块"},{"key":"D","text":"父进程与子进程不能同时使用同一临界资源"}],"hasFigure":false,"source":"curated"},{"number":30,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"对于具备设备独立性的系统下列叙述中错误的是：\nA、可以使用文件名访问物理设备；\nB、用户程序使用逻辑设备与物理设备之间的映射关系\nD、更换物理设备后必须修改访问该设备的应用程序。（缺一个选项）","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":false,"source":"curated"},{"number":31,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"某文件系统的目录由文件名和索引节点号构成。若每个目录项长度为 64 字节，其中\n4\n个字节存放索引节点号，60 个字节存放文件名。文件名由小写英文字母构成，则该文\n件系统能创建的文件数量的上限为：","options":[{"key":"A","text":"2\n26"},{"key":"B","text":"2\n32"},{"key":"C","text":"2\n60"},{"key":"D","text":"2\n64"}],"hasFigure":false,"source":"curated"},{"number":32,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"下列准则中实现临界区互斥机制必须遵循的是：\nI、 两个进\n 程不能同时进入临界区\nII、 允许进程访问空闲的临界资源\nIII、 进程等待进入临界区的时间是有限的\nIV、 不能进入临界区的执行态进程立即放弃CPU\nD、I,III,IV A、I,IV B、II,III\n C、I,II,III","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":false,"source":"curated"},{"number":33,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下图描述的协议要素是:\nI、语法 II、语义 III、时序","options":[{"key":"A","text":"I"},{"key":"B","text":"II"},{"key":"C","text":"III"},{"key":"D","text":"I，II，III"}],"hasFigure":true,"source":"curated"},{"number":34,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下列关于虚电路网络的叙述中错误的是：","options":[{"key":"A","text":"可以确保数据分组传输顺序"},{"key":"B","text":"需要为每条虚电路预分配带宽"},{"key":"C","text":"、建立虚电路时需要进行路由选择"},{"key":"D","text":"依据虚电路号（VCID）进行数据分组转发"}],"hasFigure":false,"source":"curated"},{"number":35,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"下图所示的网络冲突域和广播域的个数分别\n是：\u0001","options":[{"key":"A","text":"2，2；"},{"key":"B","text":"2，4；"},{"key":"C","text":"4，2；"},{"key":"D","text":"4，\n4；"}],"hasFigure":true,"source":"curated"},{"number":36,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"假设主机采用停-等协议向主机乙发送数据帧，数据帧长与确认帧长均为1000B。数 据传\n输速率是 10kbps，单项\n传播延时是 200ms。 则甲的最大信道利用率：","options":[{"key":"A","text":"80%；"},{"key":"B","text":"66.7%；"},{"key":"C","text":"44.4%；"},{"key":"D","text":"40%"}],"hasFigure":false,"source":"curated"},{"number":37,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"某 IEEE 802.11 无线局域网中主机 H 与 AP 之间发送或接收 CSMA/C","options":[{"key":"A","text":"帧的过程如\n下图所示，在 H 或 AP 发送帧前所等待的帧间间隔时间（IFS）中最长的是：\nA、IFS1"},{"key":"B","text":"IF\nS2"},{"key":"C","text":"IFS3"},{"key":"D","text":"IFS4"}],"hasFigure":false,"source":"curated"},{"number":38,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若主机甲与主机乙已建立一条 TCP 连接，最大段长（MSS）为 1KB，往返时间（RTT）为\n2ms，则在不出现拥塞的前提下，拥塞窗口从 8kB 增长到 32KB 所需的最长时间是：","options":[{"key":"A","text":"、4ms"},{"key":"B","text":"8ms"},{"key":"C","text":"24ms"},{"key":"D","text":"48ms"}],"hasFigure":false,"source":"curated"},{"number":39,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若主机甲与主机乙建立 TCP 连接时发送的\n SYN 段中的序号为 1000，在断开连接时，\n甲发送给乙的 FIN 段中的序号为 5001，则在无任何重传的情况下，甲向乙已经发送的应用\n层数据的字节数为：\u0001","options":[{"key":"A","text":"4002"},{"key":"B","text":"4001"},{"key":"C","text":"4000"},{"key":"D","text":"3999"}],"hasFigure":false,"source":"curated"},{"number":40,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"假设下图所示网络中的本地域名服务器只提供递归查询服务，其他域名的服务器均只提\n供迭代查询服务；局域网内主机访问 Internet 上各服务器的往返时间（RTT）均为10ms，\n忽\n略\n其他各种时延，若主机H 通过 超链接http://www.abc.com/index.html，请求浏览纯\n文本\n Web 页 index.html，则从点击超链接开始到浏览器接收到 index.html 页面为止，\n所需最短、最长时间分别是：","options":[{"key":"A","text":"10ms，40ms"},{"key":"B","text":"10ms,50ms"},{"key":"C","text":"20ms,40ms"},{"key":"D","text":"20ms,50ms"}],"hasFigure":true,"source":"curated"},{"number":41,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"定义三元组（a, b, c）（a,b,c\n均为正数）的距离 D=|a-b|+|b-c|+|c-a|. 给定 3 个非空整\n数集合 S1, S2 ,S3, 按升序分别存储在 3 个数组中。请设计一个尽可能高效的算法，计\n算并输出所有可能的三元组（a, b, c）（a∈S1,b∈S2,c∈S3）中的最小距离。例如 S1={-\n1, 0, 9}, S2=｛-\n25，-10，10，11｝，S3=｛2，9，17，30，41｝则最小距离为 2，相应\n的三元组为（9，\n10，9）要求：\n(1)给出算法的基本设计思想；\n(2)根据设计思想，采用 C 或 C++语言描述算法，关键之处给出注\n释；\n(3)说明你所设计算法的时间复杂度和空间复杂度。\n\u0001","options":[],"hasFigure":false,"source":"curated"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"若任一个字符的编码都不是其他字符编码的前缀，则称这种编码具有前缀特性。现有某\n字\n符集（字符个数≥2）的不等长编码，每个字符的编码均为二进制的\n0，1 序列，最长\n为\n L 位，且具有前缀特性。请回答下列问题：\n（\n1）哪种数据结构适宜保存上述具有前缀特性的不等长编码？\n（\n2）基于你所设计的数据结构，简述从 0/1 串到字符串的译码过程\n（3）简述判定某字符集的不等长编码是否具有前缀特性的过程","options":[],"hasFigure":false,"source":"curated"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"有实现 x*y 的两个 C 语\n 言函数如下：\nunsigned umul ( unsigned x , unsigned y)\n{ return x*y; }\nint imul ( int x, int y )\n{ return x * y; }\n假定某计算机 M 中 ALU 只能进行加\n减运算和逻辑运算。请回答：\n（1）若 M 的指令系统中没有乘法指令，但有加法、减法和位移等指令，则在 M 上也\n能实现上述两个函数中的乘法运算，为什么？\n（2）若 M 的指令系统中有乘法指令，则基于 ALU、\n位移器、寄存器以及相应控制逻\n辑实现乘法指令时，控制逻辑的作用是什么？\n（3）\n针对以下 3 种情况：（a）没有乘法指令；（b）有使用 ALU 和位移器实现的乘法\n指令；（c）有使用阵列乘法器实现的乘法指令，函数 umul()在哪种情况下执行时间最长？\n哪种情况下执行的时间最短？说明理由\n（\n4）n 位整数乘法指令可保存 2n 位乘积，当仅取低 n 位作为乘积时，其结果可能会\n发生溢出。当 n=32, x=2\n31\n-1，y=2 时，带符号整数乘法指令和无符号整数乘法指令得\n到的\n x*y 的 2n 位乘积分别是什么（用十六进制表示）？此时函数 umul()和 imul()的\n返回结果是否溢出？对于无符号整数乘法运算，\n当仅取乘积的低 n 位作为乘法结果时，\n如何用 2n 位乘积进行溢出判断？","options":[],"hasFigure":false,"source":"curated"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"假定主存地址为 32 位\n ，按字节编址，指令 Cache 和数据 Cache 与主存之间均采用 8\n路组相联映射方式，直写（Write Through）写策略和 LRU 替换算法，主存块大小为 64B，\n数据区容量各为 32KB。开始时 Cache 均为空，请回答下列问题：\n（1）\nCache 每一行中标记（Tag）、LRU 位各占几位？是否有修改位？\n（2）\n有如下 C 语言程序段：\nfor ( k = 0 ; k < 1024 ; k++ )\nS[k] = 2 * s[k];\n若数组 S 及其变量 k 均为 i\n nt 型，int 型数据占 4B，变量k分配在寄存器中，数\n组 s 在主存\n中的起始地址为 0080 00C0H，则该程序段执行过程中，访问数组 S 的数\n据 Cache 缺失次数为多少？\n（3）若 CPU 最先开始的访问操作是读取主存单元 0001 003H中的指令，简要说明从\nCache 中访问该指令的过程，包括 Cache 缺失处理过程。","options":[],"hasFigure":false,"source":"curated"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"现有\n 5 个操作 A、B、C、D 和 E，操作 C 必须在 A 和 B 完成后执行，操作 E 必须\n在 C 和 D 完成后执行，\n请使用信号量的 wait(), signal(),操作（P、 V 操作） 描述上述\n操作之间的同步关系，并说明所用信号量及其初值。","options":[],"hasFigure":false,"source":"curated"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"某 32 位系统采\n用基于二级页表的请求分页存储管理方式，按字节编址，页目录项和页\n表项长度均为 4 字节，虚拟地址结构如下：\n页目录号（10位） 页号（10位） 页内偏移量（12位）\n某 C 程序中数组 a[1024][1024]的起始虚\n拟地址为 1080 0000H，数组元素占 4 字节，\n该程序运行时，其进程的页目录起始物理地址为 0020 1000H，请回答下列问题：\n（1）数组元素 a[1][2]的虚拟地址是什么？对应的页目录号和页号分别是什么？ 对应的\n页目录项的物理地址是什么？若该目录项中存放的页框号为 00301H，则 a[1][2]所在页\n对应的页表项的物理地址是什么？\n（2）\n数组 a 在虚拟地址空间中所占区域是否必须连续？在物理地址空间中所占区域是\n否必须连续？\n（3）已知数组 a 按行优先方式存放，若对数组 a 分别按行遍历和按列遍历，则哪一种\n遍历方式的局部性更好？","options":[],"hasFigure":false,"source":"curated"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":8,"stem":"某校园网有两个局域网，通过路由器 R1、\nR2 和 R3 互联后接入 Internet， S1 和 S2\n为以太网交换机，局域网采用静态 IP 地址配置，路由器部分接口以及各主机的 IP 地\n址如图所示：\n假设 NAT 转换表结\n构为：\n外网 内网\nIP地址 端口号 IP地址 端口号\n请回答下列问题：\n（1）为使 H2 和\n H3 能够访问 Web 服务器（使用默认端口号），需要进行什么配置？\n（2）若 H2 主动访问 Web 服 务器时，将 HTTP 请求报文封装到 IP 数据 报 P 中发送，\n则 H2 发送 P 的源 IP 地 址和目的 IP 地址分别是？经过 R3 转发后，P 的源 IP 地\n址和目的 IP 地址分别是？经过 R2 转发后，P 的源 IP 地址和目的 IP 地址分别是？\n\n选择题：\n1.将一个10 * 10对称矩阵M的上三角部分的元素素푚\n푖푗\n (1≤i≤j≤10) 按列优先存\n入 C 语言的一维数组 N 中，元素푚\n7,2\n在 N 中的下标是：\nA、15 B、16 C、22 D、23\n【答案】C\n【解析】\n上三角矩阵列优先的存储模式：先存储具有一个元素第一列，再存储具有两个元素\n的第二列，以此类推\n푚\n7,2\n 说明1-6列均已存满，，故此元素是第1+2+3+4+5+6+2个被存储单元\n【注意!】C语言数组的下标从0开始\n故푚\n7,2\n在N中的下标为23-1=22，即N[22]\n2.对空栈 S 进行Push与Pop操作，入栈序列 a, b, c, d, e 经过Push，Push，Pop，\nPush，Pop，Push，Push，Pop 操作后得到的出栈序列是\nA、b,\n a, c B、b, a, e C、b, c, a D、b, c, e\n【\n答案】D\n【解析】\n操作 执行该操作后的栈(左侧为栈底) 出栈元素\nPush a\nPush ab\nPop a b\nPush ac\nPop a c\nPush ad\nPush ade\nPop ad e\n3.对于任意一棵高度为 5 且有 10 个节点的二叉树，若采用顺序存储结构保存，每个结\n点占 1 个存储单元（仅存放结点的数据信息），则存放该二叉树需要的存储单元数量\n至少是：\nA、\n31 B、16 C、15 D、10\n【答案】A\n【解析】\n2020年计算机学科专业基础综合试题","options":[],"hasFigure":true,"source":"curated"}]},{"year":2021,"title":"2021年全国硕士研究生入学统一考试 计算机学科专业基础综合 (408) 真题","totalScore":150,"timeLimit":180,"questionCount":47,"choiceCount":40,"subjectiveCount":7,"hasPdf":true,"questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知头指针h 指向一个带头结点的非空单循环链表，结点结构为\ndata\nnext\n其中next是指向直接后继结点的指针，P 是尾指针，q 是临时指针。现要删除该链表的第\n一个元素，正确的语句序列是(\n)o","options":[{"key":"A","text":"h -> next = h -> next -> next; q = h-> next; free(q);"},{"key":"B","text":"q = h -> next; h -> next = h -> next -> next; free(q);"},{"key":"C","text":"q = h-> next; h -> next = q -> next; if(p != q)p = h; free(q);"},{"key":"D","text":"q = h-> next; h -> next = q-> next; if(p == q)p = h; free(q);"}],"hasFigure":false,"source":"ocr"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知初始为空的队列Q 的一端仅能进行入队操作，另外一端既能进行入队操作又能进行出\n队操作。若Q 的入队序列是1,2, 3, 4, 5 , 则不能得到的出队序列是(\n)0","options":[{"key":"A","text":"5,4,3, 1,2"},{"key":"B","text":"5,3, 1,2,4"},{"key":"C","text":"4, 2, 1,3,5"},{"key":"D","text":"4, 1,3, 2, 5"}],"hasFigure":false,"source":"ocr"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知二维数组A 按行优先方式存储，每个元素占用1 个存储单元。若元素A[0][0]的存储地\n址是100, A[3][3]的存储地址是2 2 0 ,则元素A[5][5]的存储地址是（\n）0","options":[{"key":"A","text":"295"},{"key":"B","text":"300"},{"key":"C","text":"301"},{"key":"D","text":"306"}],"hasFigure":false,"source":"ocr"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"某森林厂对应的二叉树为T , 若T 的先序遍历序列是a, b, d, c, e, g, f , 中序遍历序列是b, d,\na, e, g, c, f , 则尸中树的棵数是（\n）o","options":[{"key":"A","text":"1"},{"key":"B","text":"2"},{"key":"C","text":"3"},{"key":"D","text":"4"}],"hasFigure":false,"source":"ocr"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若某二叉树有5 个叶结点，其权值分别为10, 12, 16, 21, 3 0 ,则其最小的带权路径长度（WPL）\n是（\n）。","options":[{"key":"A","text":"89"},{"key":"B","text":"200"},{"key":"C","text":"208"},{"key":"D","text":"289"}],"hasFigure":false,"source":"ocr"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"给定平衡二叉树如下图所示，插入关键字23后，根中的关键字是（\n）。\n（20）\n16\n30\n25\n40","options":[{"key":"A","text":"16"},{"key":"B","text":"20"},{"key":"C","text":"23"},{"key":"D","text":"25"}],"hasFigure":true,"source":"ocr"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"给定如下有向图，该图的拓扑有序序列的个数是（\n）。","options":[{"key":"A","text":"1"},{"key":"B","text":"2"},{"key":"C","text":"3"},{"key":"D","text":"4"}],"hasFigure":true,"source":"ocr"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"使用Dijkstra算法求下图中从顶点1 到其余各顶点的最短路径，将当前找到的从顶点1 到\n顶点2, 3, 4, 5 的最短路径长度保存在数组dist中，求出第二条最短路径后，dist中的内容更\n新为（\n）o","options":[{"key":"A","text":"26,3,14,6"},{"key":"B","text":"25, 3, 14, 6"},{"key":"C","text":"21,3, 14,6"},{"key":"D","text":"15,3, 14,6"}],"hasFigure":true,"source":"ocr"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"在一棵高度为3 的3 阶B 树中，根为第1 层，若第2 层中有4 个关键字，则该树的结点个\n数最多是（\n）。","options":[{"key":"A","text":"11"},{"key":"B","text":"10"},{"key":"C","text":"9"},{"key":"D","text":"8"}],"hasFigure":false,"source":"ocr"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"设数组 S[] = {93, 946, 372, 9, 146,151, 301, 485, 236, 327, 43, 892）, 采用最低位优先（LSD）\n基数排序将S 排列成升序序列。第1 趟分配、收集后，元素372之前、之后紧邻的元素分\n别是（\n）o","options":[{"key":"A","text":"43,892"},{"key":"B","text":"236,301"},{"key":"C","text":"301,892"},{"key":"D","text":"485,301"}],"hasFigure":false,"source":"ocr"},{"number":11,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"将关键字6, 9, 1,5, 8, 4, 7 依次插入到初始为空的大根堆H 中，得到的H 是（\n）。","options":[{"key":"A","text":"9, 8, 7, 6, 5, 4, 1"},{"key":"B","text":"9, 8, 7,5,6, 1,4"},{"key":"C","text":"9, 8, 7, 5, 6, 4, 1"},{"key":"D","text":"9, 6, 7, 5, 8, 4, 1"}],"hasFigure":false,"source":"ocr"},{"number":12,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"2017年公布的全球超级计算机TOP 500排名中，我国“神威•太湖之光”超级计算机蝉联\n第一，其浮点运算速度为93.0146 PFLOPS,说明该计算机每秒钟内完成的浮点操作次数约\n为（\n）0\nA. 9.3x1013 次\nB. 9.3X10” 次\nc . 9.3 千万亿次\nD. 9.3 亿亿次\n・ 002 •","options":[{"key":"A","text":"9.3x\n10\n13\n次"},{"key":"B","text":".\n9.3xJ0\n1\n5次"},{"key":"C","text":"9\n.3千万亿次"},{"key":"D","text":". 9.3亿亿次\nI\n3.\n已知带符号整数川补码表示，变队\n．｀、\ny\n、z的机器数分别为\nFFFDH\n、\nFFDFH、7FFCH,下列结论中，正确的是\nA. 若\nx\n、y和z为无符号整数，则z<x<y\nB. 若\nx\n、\ny\n和z为无符号祁数，则.'.\\\"\n< '}\n孕\n<\nz\nC. 若\nx\n、\ny和\nz\n为带符号整数，则x\n<y<\nz\nD\n.\n若\nx\n、y和z为带符号整数，则y<x<z\n14\n.\n下列数伯中，不能川\nIEEE 754浮点格式粘确表示的是\n皂一附录\nA. 1.2\n0. 1.25\n\n58-}芝》\nI\n2022\n年\n全国\n硕\n士研\n究\n生\n招\n生考试计算\n机学\n科专业基础考试大纲\nc.\n2.0\n1\n5\n. 某计算机的存储器总线中有\n2\n4\n位地\n址\n线和\n32\n位数据线，按字编\n址\n，\n字长为32位。\n若00\n0000\nH\n-3 F\nFFFFH\n为RAM\n区\n，\n则需要\n5\n1\n2Kx8位的R\nAM芯片数为\nD\n.\n2.5\nA. 8\nC.\n32\n64\n16\n．\n．\nBD\n1\n6\n.\n若计货机主存地址为3\n2\n位，按字节编址，Cache\n数据区大小为\n32 KB.\n主存块大小为\n3\n2\nB, 采川直桵映射方式和回写(W百te\nB\nack)策略\n，\n则Cache行的位数至少是\nA.\n2\n75\nC.\n258\nB.\n2\n7\n4\nD. 257\n17.\n下列寄存器中，汇编语言程序员可见的是\nI .\n指令寄存器\nII\n.\n微指令寄存器\nm.\n基址寄存器\nN.\n标志／状态寄存器\nA.\n仅I、II\nB. 仅I、W\nC. 仅II、N\nD. 仅皿、W\n1\n8\n.\n下列关于数据通路的叙述中，错误的是\nA.\n数据通路包含\nA\nLU等组合逻辑（操作）元件\nB\n.\n数\n据通路包含寄存器等时序逻辑（状态）元件\nC. 数据通路不包含用于异楷串件检测及响应的电路\nD. 数机通路中的\n数\n据流动路径山，控制伈号进行控制\n19.\n下列关于总线的叙述中，估误的是\nA.\n总线是在两个或多个部件之间进行数趴交换的传愉介质\nB\n.\n同步总线山时钟估\n勺定\n时，时钟\n肋冲不\n一定等于工\n作频率\nC\n.\n异步总\n线\n由腥手伈号定\n时，一次\nlht\n手过和\n完成一位数据交换\nD\n.\n突发(Burst)传送总线串务可以在总线上迕纹传送多个数剿\n2\n0. 下列选项中，不屈于\n1/0拔口的是\nA. 磁盘驱动器\n0.\n打\n印机适配器\n\nc.\n网络控制器\nD.\n可\n编程中断控制器\n59\n21.\n异常事件在当前指令执行过程中进行检测，中断诮求则在当前指\n入\n执行\n后\n进行\n检测。\n下列\n事件中\n，相\n应处理程序执\n行\n后\n，必\n须\n匝\n到当前指令重新执行的是\nA.\n系\n统调用\nB.\n页缺失\nC.\nDMA传送结束\nD.\n打印机\n缺纸\n22.\n下列是关于多重中断系\n统中\nC\nPU\n响应中断的叙述，其中错误\n的是\nA.\n仅在用户态（执行用户程序）下，\nC\nPU才能检测和响应中断\nB.\nC\nP\nU\n只有在检测到中断请求信号后，才会进入中断响应周期\nc.\n进入中断响应周期时，\nC\nPU\n一\n定处于中断允许（开中断）状态\nD.\n若C\nP\nU\n检\n测到中断请求信号，则\n一\n定存在未被屏蔽的中断源\n请求信号\n23.\n下列指令中，只能在内核态执行的是\nA.\ntrap指令\nB.\nI/0指令\nC.\n数据传送指令\nD.\n设\n置断点指令\n2\n4\n.\n下列操作中，操作系统在创建新进程时，必须完成的是\nI\n.\n申请空白的进程控制块\nII\n. 初始化进程控制块\n皿设置进程状态为执行态\nA.\n{又I\nB\n.\n仅I、II\nC.\n仅I、皿\nD\n. 仅11、\nm\n25.\n下列内核的数据结构或程序中，分时系统实现时间片轮转调度需\n要使用的是\n皂\n一附录\nI .\n进程控制块\nm\n.\n进程就绪队列\nA.\n仅1I、\nm\nC.\n仅I、\nIl、\nm\nn.\n时钟中断处理程序\nIV.\n进程阻塞队列\nIl.\n仅\nI\n、\nIV\nD\n.\n仅I、I\nl、W\n26\n.\n某系统中磁盘的磁道数为\n200\n(0\n- 199)\n,\n磁头当前在184\n号磁道\n\n60\n一\n志\n芒\n2022\n年\n全国硕\n士\n研究\n生\n招生考试计算机学科\n专\n业\n基\n础考试大纲\n上\n。 川户进程捉出的\n磁\n盘访问诮求对应\n的磁迫号依次为\n1\n8\n4\n、\n1\n8\n7\n、\n176、1\n8\n2、\n199。 若采川服短寻\n迫\n时间优先册度符法(SSTF)\n宅成磁盘访问，则磁头移动的卧商（磁迫数）是\nA. 37\nc.\n4\n1\nB. 38\nD.\n42\n2\n7.\n下\n列咑件中，可能引起进程调度和序执行的是\nI .\n中断处理结束\nm.\n进程执行结束\nII\n.\n进程阳塞\nN.进程的时间片用兀\nA. 仅\n1\n、\nm\nC. 仅川、W\n28\n. 某诘求分页存储系统的页大小为\n4\nKB, 按字节编址。\n系统给进\n程\nP\n分配\n2\n个固定的页框，并采用改进型\nClock\n置换算法，进程\nP\n页表的部分内容如下表所示。\nB. 仅II , N\nD.\nI\n、II、\nm\n和W\n页号\n234\n存在位\n访问位修改位\n页框号\nl : 修改，0:未修改\nI\n: 存在，0:不存在\nI : 访问，0:未访问\n...\n...\n．．．\n．．．\n20 H\n。\n。\n。\n60 H\nl\nI\n。\n80 H\nI\nI\nl\n．．．\n．．．\n...\n...\n若P访问虚拟地址为\n02\nAO\nI\nH的存储t)t元，则经地址变换后得到\n的物理地址见\nA. OOAOI JI\nC. 6\n0\nAOIH\nB. 20AOI I\nI\nD. 80AO 111\n29\n.\n在采川二级页表的分页系统中，CPU\n页表拈址寄存监中的内容是\nA.\n当\n前进程的一级页表的起始f.l�拟地址\n\nB\n. 当前进程的一级页表的起始物理地址\nc.\n当前进程的\n二级页表的起始虚拟地址\nD. 当前\n进\n程的二\n级页表的起始物理地址\n录dir下有文件file\n1\n, 则为删除该文件内核\n不\n必完成的工\n30. 若\n作\n是\nA\n.\n删除file\n1\n的快捷方寸\nB\n. 释放file1的文件控制块\n61－辜翠〉－附录\nC. 释放file1\n占用的磁盘空间\nD. 删除目录dir中与\nfi1e1\n对应的目录项\n3\n1\n. 若系统中有\n11(11�2)\n个进程，每个进程均需要使用某类临界资源\n2个\n，\n则系统\n不\n会发生死锁所需的该类资源总数至少是\nA.2\nC. n+I\nB. n\nD. 2n\n32.\n下列选项中，通过系统调用完成的操作是\nB.\n进程\n涸\n度\nD.\n生\n成随机整数\n33. 在T\nC\nP/IP参考模型中，由传输层相邻的下一层实现的主要功\nA.\n页置换\nC. 创建新进\n程\n能是\nA.\n对话管\n理\nB.\n路由选\n择\nC.\n端\n到端报文段传输\nD\n.\n结\n点到结点流狱控制\n34.\n若\n下图为一段差分曼彻斯特编码估号波形，则其编码的二进制位\n串是\nA\n.\nl O I 1\n1001\nB. 110 I 000 l\n\n62\n＿辜患〉一\nN\n022\n年\n全\n国硕\n士研究生招\n生\n考试计算机学科专业基础考试大纲\nC. 00 I\nO\n11 I 0\nD. 1011 0110\n35\n.\n现将\n一\n个JP网络划\n分为3个子\n网，若其中\n一\n个子网是\n192.168.9.\n128/26,\n则下列网络中，不可能是另外两\n个子\n网之\n一\n的\n是\nA. 192.168.9.0/2\n5\nC. 192.168.9.192/26\nB\n. 192.168.9.0/26\nD. 192.168.9.192/27\n3\n6.\n若路由器向MTU =\n800\nB\n的\n链路转发一个总\n长\n度为\n1\n5\n80\nB的\nI\nP数据报（首部长度为\n20\nB)时，进行了分片，且每个分片尽可能\n大，则第\n2\n个分片的总长度字段和\nM\nF标志位的值分别是\nA. 796, 0\nB. 796, I\nC. 800, 0\nD\n. 800, 1\n3\n7.\n某网络中的\n所有路由器均采用距离向批路由算法计算路由。若\n路由器E与邻居路由器\nA\n、B、\nC\n和\nD\n之间的直接链路距离分别是\n8\n、\nI\nO\n、1\n2\n和\n6,\n且E收到邻居路由器的距离向量如下表所示，则路\n由器E更新后的到达目的网络\nN\nell -Net4的距离分别是\n目的网络\nA的距离向盘\nB的距离向耳\nC的距离向扯\nD的距离向扭\nNetl\nNet2\nNet3\nNet4\nl\n23\n20\n22\n12\n35\n30\n28\n24\n18\n16\n36\n36\n30\n8\n24\nA.\n9, IO, 12,\n6\nB. 9, IO, 28, 20\nC. 9,20, 12,20\nD. 9,20,28,20\n3\n8.\n若客户首先向服务器发送\nF\nI\nN段沽求断开\nT\nCP迕接\n，\n则当客户\n收到服务器发送的FIN段并向服务器发送了\nA\nCK段后，客户的\nTCP状态转换\n为\nA. CLOSE_WAIT\nI\nJ. T\nIM\nE_ \\Y./ A lT\nC. FI\nN\n_ WAIT _l\nD. FIN_ WAIT_2\n3\n9.\n若大小为\n12\nB的应用层数据分别通过\n1\n个\nUDP数据报和\n1\n个\n\nTC\nP\n段传\n输\n，则该U\nDP\n数据报和TCP段实现的有效载荷（应用\n云数据）最大传\n输\n效率分别是\n63\nA. 37.5%.\n16.7%\nB. 37.5%\n,37.5%\nC. 60. 0%, 16.7%\nD\n. 60.0% 37.5%\n4\n0.\n假设主机甲通过\nT\nCP向主机乙发\n送数据，部分过和如下\n图所7\n八\no\n甲在I。时刻发送了一个序号se\nq=\n501\n、封装2\n00\nB数据的段，在tI\n时刻收到乙发送的序\n号s\neq=\n60\n1\n、确认序号ack_seq=\n50\nl、按\n收\n窗\nrcvwnd\n= 500 B的段，则甲在未收到新的确认段之前可以继续\n向乙发送的数据序号范围是\n附录\n拿\nI。三B数据\n1\n1\n时间\nA. 501 -1000\nC.701-1000\nseq\n==6\n01,\na\nck\n_\nse\nq\n=\n50\n1,r\nc\nvw\nn\nd\n今\nOO\nB\n乙\nca\nB. 601 -1100\nD.\n801-1100\n二\n、"}],"hasFigure":false,"source":"ocr"},{"number":13,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"已知带符号整数用补码表示，变量x ,y ,z 的机器数分别为FFFDH,FFDFH,7FFCH,下列结\n论中，正确的是（\n）o","options":[{"key":"A","text":"若x j 和z 为无符号整数，贝Ijz v x v y"},{"key":"B","text":"若x j 和z 为无符号整数，贝UxVyVz"},{"key":"C","text":"若x j 和z 为带符号整数，贝Ijx v y v z"},{"key":"D","text":"若x j 和z 为带符号整数，贝仃v x 〈z"}],"hasFigure":false,"source":"ocr"},{"number":14,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列数值中，不能用IEEE 754浮点格式精确表示的是（\n）。","options":[{"key":"A","text":"1.2"},{"key":"B","text":"1.25"},{"key":"C","text":"2.0"},{"key":"D","text":"2.5"}],"hasFigure":false,"source":"ocr"},{"number":15,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某计算机的存储器总线中有2 4 位地址线和3 2 位数据线，按字编址，字长为3 2 位。如果\n00 0000H〜3FFFFFH为RAM区，那么需要512Kx8 位的RAM芯片数为（\n）。","options":[{"key":"A","text":"8"},{"key":"B","text":"16"},{"key":"C","text":"32"},{"key":"D","text":"64"}],"hasFigure":false,"source":"ocr"},{"number":16,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"若计算机主存地址为3 2 位，按字节编址，Cache数据区大小为3 2 K B ,主存块大小为32B,\n采用直接映射方式和回写（Write Back）策略，则Cache行的位数至少是（\n）。","options":[{"key":"A","text":"275"},{"key":"B","text":"274"},{"key":"C","text":"258"},{"key":"D","text":"257"}],"hasFigure":false,"source":"ocr"},{"number":17,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列寄存器中，汇编语言程序员可见的是（\n）o\nI.指令寄存器\nI I . 微指令寄存器\nI I I .基址寄存器\nA. 仅 I、II\nB. 仅 I、IV\nC. 仅 n 、IV","options":[{"key":"A","text":"仅I、II"},{"key":"B","text":"仅I、W"},{"key":"C","text":"仅II、N"},{"key":"D","text":"仅皿、W\n1\n8\n.\n下列关于数据通路的叙述中，错误的是\nA.\n数据通路包含\nA\nLU等组合逻辑（操作）元件\nB\n.\n数\n据通路包含寄存器等时序逻辑（状态）元件\nC. 数据通路不包含用于异楷串件检测及响应的电路\nD. 数机通路中的\n数\n据流动路径山，控制伈号进行控制\n19.\n下列关于总线的叙述中，估误的是\nA.\n总线是在两个或多个部件之间进行数趴交换的传愉介质\nB\n.\n同步总线山时钟估\n勺定\n时，时钟\n肋冲不\n一定等于工\n作频率\nC\n.\n异步总\n线\n由腥手伈号定\n时，一次\nlht\n手过和\n完成一位数据交换\nD\n.\n突发(Burst)传送总线串务可以在总线上迕纹传送多个数剿\n2\n0. 下列选项中，不屈于\n1/0拔口的是\nA. 磁盘驱动器\n0.\n打\n印机适配器\n\nc.\n网络控制器\nD.\n可\n编程中断控制器\n59\n21.\n异常事件在当前指令执行过程中进行检测，中断诮求则在当前指\n入\n执行\n后\n进行\n检测。\n下列\n事件中\n，相\n应处理程序执\n行\n后\n，必\n须\n匝\n到当前指令重新执行的是\nA.\n系\n统调用\nB.\n页缺失\nC.\nDMA传送结束\nD.\n打印机\n缺纸\n22.\n下列是关于多重中断系\n统中\nC\nPU\n响应中断的叙述，其中错误\n的是\nA.\n仅在用户态（执行用户程序）下，\nC\nPU才能检测和响应中断\nB.\nC\nP\nU\n只有在检测到中断请求信号后，才会进入中断响应周期\nc.\n进入中断响应周期时，\nC\nPU\n一\n定处于中断允许（开中断）状态\nD.\n若C\nP\nU\n检\n测到中断请求信号，则\n一\n定存在未被屏蔽的中断源\n请求信号\n23.\n下列指令中，只能在内核态执行的是\nA.\ntrap指令\nB.\nI/0指令\nC.\n数据传送指令\nD.\n设\n置断点指令\n2\n4\n.\n下列操作中，操作系统在创建新进程时，必须完成的是\nI\n.\n申请空白的进程控制块\nII\n. 初始化进程控制块\n皿设置进程状态为执行态\nA.\n{又I\nB\n.\n仅I、II\nC.\n仅I、皿\nD\n. 仅11、\nm\n25.\n下列内核的数据结构或程序中，分时系统实现时间片轮转调度需\n要使用的是\n皂\n一附录\nI .\n进程控制块\nm\n.\n进程就绪队列\nA.\n仅1I、\nm\nC.\n仅I、\nIl、\nm\nn.\n时钟中断处理程序\nIV.\n进程阻塞队列\nIl.\n仅\nI\n、\nIV\nD\n.\n仅I、I\nl、W\n26\n.\n某系统中磁盘的磁道数为\n200\n(0\n- 199)\n,\n磁头当前在184\n号磁道\n\n60\n一\n志\n芒\n2022\n年\n全国硕\n士\n研究\n生\n招生考试计算机学科\n专\n业\n基\n础考试大纲\n上\n。 川户进程捉出的\n磁\n盘访问诮求对应\n的磁迫号依次为\n1\n8\n4\n、\n1\n8\n7\n、\n176、1\n8\n2、\n199。 若采川服短寻\n迫\n时间优先册度符法(SSTF)\n宅成磁盘访问，则磁头移动的卧商（磁迫数）是\nA. 37\nc.\n4\n1\nB. 38\nD.\n42\n2\n7.\n下\n列咑件中，可能引起进程调度和序执行的是\nI .\n中断处理结束\nm.\n进程执行结束\nII\n.\n进程阳塞\nN.进程的时间片用兀\nA. 仅\n1\n、\nm\nC. 仅川、W\n28\n. 某诘求分页存储系统的页大小为\n4\nKB, 按字节编址。\n系统给进\n程\nP\n分配\n2\n个固定的页框，并采用改进型\nClock\n置换算法，进程\nP\n页表的部分内容如下表所示。\nB. 仅II , N\nD.\nI\n、II、\nm\n和W\n页号\n234\n存在位\n访问位修改位\n页框号\nl : 修改，0:未修改\nI\n: 存在，0:不存在\nI : 访问，0:未访问\n...\n...\n．．．\n．．．\n20 H\n。\n。\n。\n60 H\nl\nI\n。\n80 H\nI\nI\nl\n．．．\n．．．\n...\n...\n若P访问虚拟地址为\n02\nAO\nI\nH的存储t)t元，则经地址变换后得到\n的物理地址见\nA. OOAOI JI\nC. 6\n0\nAOIH\nB. 20AOI I\nI\nD. 80AO 111\n29\n.\n在采川二级页表的分页系统中，CPU\n页表拈址寄存监中的内容是\nA.\n当\n前进程的一级页表的起始f.l�拟地址\n\nB\n. 当前进程的一级页表的起始物理地址\nc.\n当前进程的\n二级页表的起始虚拟地址\nD. 当前\n进\n程的二\n级页表的起始物理地址\n录dir下有文件file\n1\n, 则为删除该文件内核\n不\n必完成的工\n30. 若\n作\n是\nA\n.\n删除file\n1\n的快捷方寸\nB\n. 释放file1的文件控制块\n61－辜翠〉－附录\nC. 释放file1\n占用的磁盘空间\nD. 删除目录dir中与\nfi1e1\n对应的目录项\n3\n1\n. 若系统中有\n11(11�2)\n个进程，每个进程均需要使用某类临界资源\n2个\n，\n则系统\n不\n会发生死锁所需的该类资源总数至少是\nA.2\nC. n+I\nB. n\nD. 2n\n32.\n下列选项中，通过系统调用完成的操作是\nB.\n进程\n涸\n度\nD.\n生\n成随机整数\n33. 在T\nC\nP/IP参考模型中，由传输层相邻的下一层实现的主要功\nA.\n页置换\nC. 创建新进\n程\n能是\nA.\n对话管\n理\nB.\n路由选\n择\nC.\n端\n到端报文段传输\nD\n.\n结\n点到结点流狱控制\n34.\n若\n下图为一段差分曼彻斯特编码估号波形，则其编码的二进制位\n串是\nA\n.\nl O I 1\n1001\nB. 110 I 000 l\n\n62\n＿辜患〉一\nN\n022\n年\n全\n国硕\n士研究生招\n生\n考试计算机学科专业基础考试大纲\nC. 00 I\nO\n11 I 0\nD. 1011 0110\n35\n.\n现将\n一\n个JP网络划\n分为3个子\n网，若其中\n一\n个子网是\n192.168.9.\n128/26,\n则下列网络中，不可能是另外两\n个子\n网之\n一\n的\n是\nA. 192.168.9.0/2\n5\nC. 192.168.9.192/26\nB\n. 192.168.9.0/26\nD. 192.168.9.192/27\n3\n6.\n若路由器向MTU =\n800\nB\n的\n链路转发一个总\n长\n度为\n1\n5\n80\nB的\nI\nP数据报（首部长度为\n20\nB)时，进行了分片，且每个分片尽可能\n大，则第\n2\n个分片的总长度字段和\nM\nF标志位的值分别是\nA. 796, 0\nB. 796, I\nC. 800, 0\nD\n. 800, 1\n3\n7.\n某网络中的\n所有路由器均采用距离向批路由算法计算路由。若\n路由器E与邻居路由器\nA\n、B、\nC\n和\nD\n之间的直接链路距离分别是\n8\n、\nI\nO\n、1\n2\n和\n6,\n且E收到邻居路由器的距离向量如下表所示，则路\n由器E更新后的到达目的网络\nN\nell -Net4的距离分别是\n目的网络\nA的距离向盘\nB的距离向耳\nC的距离向扯\nD的距离向扭\nNetl\nNet2\nNet3\nNet4\nl\n23\n20\n22\n12\n35\n30\n28\n24\n18\n16\n36\n36\n30\n8\n24\nA.\n9, IO, 12,\n6\nB. 9, IO, 28, 20\nC. 9,20, 12,20\nD. 9,20,28,20\n3\n8.\n若客户首先向服务器发送\nF\nI\nN段沽求断开\nT\nCP迕接\n，\n则当客户\n收到服务器发送的FIN段并向服务器发送了\nA\nCK段后，客户的\nTCP状态转换\n为\nA. CLOSE_WAIT\nI\nJ. T\nIM\nE_ \\Y./ A lT\nC. FI\nN\n_ WAIT _l\nD. FIN_ WAIT_2\n3\n9.\n若大小为\n12\nB的应用层数据分别通过\n1\n个\nUDP数据报和\n1\n个\n\nTC\nP\n段传\n输\n，则该U\nDP\n数据报和TCP段实现的有效载荷（应用\n云数据）最大传\n输\n效率分别是\n63\nA. 37.5%.\n16.7%\nB. 37.5%\n,37.5%\nC. 60. 0%, 16.7%\nD\n. 60.0% 37.5%\n4\n0.\n假设主机甲通过\nT\nCP向主机乙发\n送数据，部分过和如下\n图所7\n八\no\n甲在I。时刻发送了一个序号se\nq=\n501\n、封装2\n00\nB数据的段，在tI\n时刻收到乙发送的序\n号s\neq=\n60\n1\n、确认序号ack_seq=\n50\nl、按\n收\n窗\nrcvwnd\n= 500 B的段，则甲在未收到新的确认段之前可以继续\n向乙发送的数据序号范围是\n附录\n拿\nI。三B数据\n1\n1\n时间\nA. 501 -1000\nC.701-1000\nseq\n==6\n01,\na\nck\n_\nse\nq\n=\n50\n1,r\nc\nvw\nn\nd\n今\nOO\nB\n乙\nca\nB. 601 -1100\nD.\n801-1100\n二\n、"}],"hasFigure":false,"source":"ocr"},{"number":18,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列关于数据通路的叙述中，错误的是（\n）0","options":[{"key":"A","text":"数据通路包含ALU等组合逻辑（操作）元件"},{"key":"B","text":"数据通路包含寄存器等时序逻辑（状态）元件"},{"key":"C","text":"数据通路不包含用于异常事件检测及响应的电路"},{"key":"D","text":"数据通路中的数据流动路径由控制信号进行控制"}],"hasFigure":false,"source":"ocr"},{"number":19,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列关于总线的叙述中，错误的是（\n）o","options":[{"key":"A","text":"总线是在两个或多个部件之间进行数据交换的传输介质"},{"key":"B","text":"同步总线由时钟信号定时，时钟频率不一定等于工作频率"},{"key":"C","text":"异步总线由握手信号定时，一次握手过程完成一位数据交换"},{"key":"D","text":"突发（Burst）传送总线事务可以在总线上连续传送多个数据"}],"hasFigure":false,"source":"ocr"},{"number":20,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列选项中，不属于I/O接口的是（\n）o","options":[{"key":"A","text":"磁盘驱动器"},{"key":"B","text":"打印机适配器"},{"key":"C","text":"网络控制器\nI V .标志/状态寄存器"},{"key":"D","text":"仅 n i、iv"}],"hasFigure":false,"source":"ocr"},{"number":21,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"异常事件在当前指令执行过程中进行检测，中断请求则在当前指令执行后进行检测。下列\n事件中，相应处理程序执行后，必须回到当前指令重新执行的是（\n）o","options":[{"key":"A","text":"系统调用"},{"key":"B","text":"页缺失"},{"key":"C","text":"DM 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l,则为删除该文件内核不必完成的工作是（\n）\no","options":[{"key":"A","text":"删除file l的快捷方式"},{"key":"B","text":"释放file l的文件控制块"},{"key":"C","text":"释放file l占用的磁盘空间"},{"key":"D","text":"删除目录dir中与filel对应的目录项"}],"hasFigure":false,"source":"ocr"},{"number":31,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"若系统中有〃（〃2 2 ）个进程，每个进程均需要使用某类临界资源2 个，则系统不会发生\n死锁所需的该类资源总数至少是（\n)o","options":[{"key":"A","text":"2"},{"key":"B","text":"n"},{"key":"C","text":"〃 + 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0110"}],"hasFigure":true,"source":"curated"},{"number":35,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"现将一个IP 网络划分为3 个子网,\n不可能是另外两个子网之一的是（\nA. 192.168.9.0/25\nC. 192.168.9.192/26\nC. 0010 1110\nD. 1011 0110\n若其中一个子网是192.168.9.128/26,则下列网络中,\n)\nO\nB. 192.168.9.0/26\nD. 192.168.9.192/27","options":[{"key":"A","text":"192.168.9.0/2\n5\nC. 192.168.9.192/26"},{"key":"B","text":". 192.168.9.0/26\nD. 192.168.9.192/27\n3\n6.\n若路由器向MTU =\n800\nB\n的\n链路转发一个总\n长\n度为\n1\n5\n80\nB的\nI\nP数据报（首部长度为\n20\nB)时，进行了分片，且每个分片尽可能\n大，则第\n2\n个分片的总长度字段和\nM\nF标志位的值分别是\nA. 796, 0\nB. 796, I"},{"key":"C","text":"800, 0"},{"key":"D","text":". 800, 1\n3\n7.\n某网络中的\n所有路由器均采用距离向批路由算法计算路由。若\n路由器E与邻居路由器\nA\n、B、\nC\n和\nD\n之间的直接链路距离分别是\n8\n、\nI\nO\n、1\n2\n和\n6,\n且E收到邻居路由器的距离向量如下表所示，则路\n由器E更新后的到达目的网络\nN\nell -Net4的距离分别是\n目的网络\nA的距离向盘\nB的距离向耳\nC的距离向扯\nD的距离向扭\nNetl\nNet2\nNet3\nNet4\nl\n23\n20\n22\n12\n35\n30\n28\n24\n18\n16\n36\n36\n30\n8\n24\nA.\n9, IO, 12,\n6\nB. 9, IO, 28, 20\nC. 9,20, 12,20\nD. 9,20,28,20\n3\n8.\n若客户首先向服务器发送\nF\nI\nN段沽求断开\nT\nCP迕接\n，\n则当客户\n收到服务器发送的FIN段并向服务器发送了\nA\nCK段后，客户的\nTCP状态转换\n为\nA. 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FIN_ WAIT_2\n3\n9.\n若大小为\n12\nB的应用层数据分别通过\n1\n个\nUDP数据报和\n1\n个\n\nTC\nP\n段传\n输\n，则该U\nDP\n数据报和TCP段实现的有效载荷（应用\n云数据）最大传\n输\n效率分别是\n63\nA. 37.5%.\n16.7%\nB. 37.5%\n,37.5%\nC. 60. 0%, 16.7%\nD\n. 60.0% 37.5%\n4\n0.\n假设主机甲通过\nT\nCP向主机乙发\n送数据，部分过和如下\n图所7\n八\no\n甲在I。时刻发送了一个序号se\nq=\n501\n、封装2\n00\nB数据的段，在tI\n时刻收到乙发送的序\n号s\neq=\n60\n1\n、确认序号ack_seq=\n50\nl、按\n收\n窗\nrcvwnd\n= 500 B的段，则甲在未收到新的确认段之前可以继续\n向乙发送的数据序号范围是\n附录\n拿\nI。三B数据\n1\n1\n时间\nA. 501 -1000\nC.701-1000\nseq\n==6\n01,\na\nck\n_\nse\nq\n=\n50\n1,r\nc\nvw\nn\nd\n今\nOO\nB\n乙\nca\nB. 601 -1100\nD.\n801-1100\n二\n、"}],"hasFigure":false,"source":"ocr"},{"number":36,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若路由器向MTU = 800B的链路转发一个总长度为1580B的IP数据报（首部长度为20B）\n时，进行了分片，且每个分片尽可能大，则第2 个分片的总长度字段和MF标志位的值分\n别是（\n）o","options":[{"key":"A","text":"796,0"},{"key":"B","text":"796, 1"},{"key":"C","text":"800,0"},{"key":"D","text":"800, 1"}],"hasFigure":false,"source":"ocr"},{"number":37,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"某网络中的所有路由器均采用距离向量路由算法计算路由。若路由器E 与邻居路由器A,B,\nC 和D 之间的直接链路距离分别是8, 10, 12和6 , 且E 收到邻居路由器的距离向量如下表\n所示，则路由器E 更新后的到达目的网络Netl〜Net4的距离分别是（\n）。\n・ 005 •\n\n目的网络\nA 的距离向量\nB 的距离向量\nC 的距离向量\nD 的距离向量\n1\n23\n20\n22\n12\n35\n30\n28\n24\n18\n16\n36\n36\n30\n8\n24","options":[{"key":"A","text":"9, 10, 12, 6"},{"key":"B","text":"9, 10, 28, 20"},{"key":"C","text":"9, 20, 12, 20"},{"key":"D","text":"9,20,28,20"}],"hasFigure":true,"source":"ocr"},{"number":38,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若客户首先向服务器发送FIN 段请求断开TCP连接，则当客户收到服务器发送的FIN 段并\n向服务器发送了 ACK段后，客户的TCP状态转换为（\n）。","options":[{"key":"A","text":"CLOSE_WAIT"},{"key":"B","text":"TIME_WAIT"},{"key":"C","text":"FIN_WAIT_1"},{"key":"D","text":"FIN_WAIT_2"}],"hasFigure":false,"source":"ocr"},{"number":39,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"若大小为12B的应用层数据分别通过1 个UDP数据报和1 个TCP段传输，则该UDP数据\n报和TCP段实现的有效载荷（应用层数据）最大传输效率分别是（\n）。","options":[{"key":"A","text":"37.5%, 16.7%"},{"key":"B","text":"37.5%, 37.5%"},{"key":"C","text":"60.0%, 16.7%"},{"key":"D","text":"60.0%, 37.5%"}],"hasFigure":false,"source":"ocr"},{"number":40,"type":"CHOICE","subject":"cn","subjectName":"计算机网络","score":2,"stem":"设主机甲通过TC P向主机乙发送数据，部分过程如下图所示。甲在而时刻发送一个序号seq =\n501、封装200B数据的段，在4 时刻收到乙发送的序号seq = 601、确认序号ack_seq = 501、\n接收窗口 rcvwnd = 500B的段，则甲在未收到新的确认段之前，可以继续向乙发送的数据序号\n范围是（\n）。\n二、综合应用题\n第41〜47小题，共70分。","options":[{"key":"A","text":"选项 A"},{"key":"B","text":"选项 B"},{"key":"C","text":"选项 C"},{"key":"D","text":"选项 D"}],"hasFigure":true,"source":"ocr"},{"number":41,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"（15分）已知无向连通图G 由顶点集P 和边集E 组成，|^| > 0 , 当G 中度为奇数的顶点个\n数为不大于2 的偶数时，G 存在包含所有边且长度为区|的路径（称为E L 路径）。设图G\n采用邻接矩阵存储，类型定义如下：\ntypedef struct{\n//图的定义\nint numVertices,numEdges;\n//图中实际的顶点数和边数\nchar VerticesList[MAXV];\n//顶点表。MAXV为已定义常量\nint Edge[MAXV][MAXV]；\n・ 006 ・\n\n//邻接矩阵\n}MGraph;\n请设计算法i n t IsExistEL(M G raph G ), 判断G 是否存在E L 路径，若存在，则返回\n1 , 否则返回0。要求：\n1 ) 给出算法的基本设计思想。\n2 ) 根据设计思想，采用C 或C++语言描述算法，关键之处给出注释。\n3 ) 说明你所设计算法的时间复杂度和空间复杂度。","options":[],"hasFigure":true,"source":"ocr"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":8,"stem":"( 8 分)已知某排序算法如下：\nvoid cmpCountSort(int a [],int b [],int n)\n{\nint i,j,*count;\ncount=(int *)malloc(sizeof(int)*n);\n//C++语言：count=new int [n];\nfor(i=0;i<n;i++)\ncount[i]=0;\nfor(i=0;i<n-l;i++)\nfor(j=i + l;j <n;j ++)\nif(a[i]<a[j]) count[j]++;\nelse\ncount[i]++;\nfor(i=0;i<n;i++)\nb[count[i]]= a [i];\nfree (count) ;\n//C++语言：delete count;\n)\n请回答下列问题。\n1 ) 若有 in t a [ ] = { 2 5 ,-1 0 z 2 5 ,1 0 z l l z 1 9 } , b [ 6 ] 则调用 cmpCountSort (a, b, 6)\n后数组b 中的内容是什么？\n2 ) 若a 中含有〃个元素，则算法执行过程中，元素之间的比较次数是多少？\n3 ) 该算法是稳定的吗？若是，则阐述理由；否则，修改为稳定排序算法。","options":[],"hasFigure":false,"source":"ocr"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"(15 分)假定计算机M 字长为16位，按字节编址，连接CPU和主存的系统总线中地址线\n为20位、数据线为8 位，采用16位定长指令字，指令格式及其说明如下：\n格式\n6 位\n2 位\n2 位\n2 位\n4 位\n指令功能或指令类型说明\nR 型\n000000\nrs\nFt\nrd\nopl\nR[rd] - 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struct\n1/图的类型定义\nintnumVertices，numEdges；//图的顶点数和有向边数\nchar VerticesList[MAxV];\n//顶点表，MAXV为已定义常量\nint Edge[MAXV][MAXV];\n1/邻接矩阵\nMGraph;\n将图中出度大于人度的顶点称为K顶点。例如：在右图中，顶点a和顶\n点b都是K顶点。请设计算法：intprintVertices（MGraphG），\n对任意给定的非空有向图G，输出图G中所有的K顶点，并返回K顶\n点的个数。要求：\n(1)给出算法的基本设计思想。\n(2)根据设计思想，采用C或C++语言描述算法，关键之处给出注释。","options":[],"hasFigure":true,"source":"ocr"},{"number":42,"type":"SUBJECTIVE","subject":"ds","subjectName":"数据结构","score":15,"stem":"(10分)对含有n(n>0)个记录的文件进行外部排序，采用置换－选择排序生成初始归并段时需\n要使用一个工作区，工作区中能保存m个记录，请回答下列问题：\n(1）若文件中有19个记录，其关键字依次是51，94，37，92，14，63，15，99，48，56，23，60，\n31，17，43，8，90，166，100。当m=4时，可生成几个初始归并段？每个归并段各是什么？\n(2）对任意m(n》m>0)，生成的第一个初始归并段的长度最大值和最小值分别是多少？","options":[],"hasFigure":false,"source":"ocr"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"（14分)已知计算机M字长为32位，按字节编址，采用请求调页策略的虚拟存储管理方式，虚\n拟地址32位，页大小为4KB；数据Cache采用4路组相联映射方式，数据区大小为8KB，主存\n块大小为32B。现有C语言程序段如下：\ninta[24][24];\nfor（i=0;i<24;i++)\nfor（j=0;j<64;j++)\na[i][j] =10;\n已知二维数组a按行优先存储，在虚拟地址空间中分配的起始地址为 00422000H，sizeof(int)=\n4，假定在M上执行上述程序段之前数组a不在内存，且在该程序段执行过程中不会发生页面\n置换。请回答下列问题：\n(1）数组a分布在几个页面中？对于数组a的访问，会发生几次缺页异常？页故障地址各是什么？\n(2）不考虑对变量i和j，该程序段的数据访问是否具有时间局部性？为什么？\n(3）计算机M的虚拟地址（A31～A0）中哪几位用作块内地址？哪几位用作Cache组号？数组\n元素a[1]I0]的虚拟地址是多少？其所在主存块对应的Cache组号是多少？\n(4）数组a总共占多少主存块？假设上述程序段执行过程中数组a的访问不会和其他数据发生\nCache访问冲突，则数组a的Cache命中率是多少？若将循环中i和j的次序按如下方式调\n换，则数组a的Cache命中率又是多少？\nfor（j=0；j<64;j++)\nfor（i=0;i<24;i++)\na[i][j]=10;","options":[],"hasFigure":false,"source":"ocr"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"(9分)题43中C程序段在计算机M上的部分机器级代码如下，每个机器级代码行中依次包含\n指令序号、虚拟地址、机器指令和汇编指令。\nfor (i =0;i<24;i++)\n1\n00401072\nC745F800000000\nmov[ebp - 8], 0\n2\n00401079\nEB 09\njmp 00401084h\n3\n0040107B\n8B 55F8\nmov eax,[ebp - 8]\n7\n00401088\n7D32\njge 004010bch\nfor (j= 0;j<64;j++)\n8\n0040108AC745FC00000000\nmov[ebp - 4], 0\na[i]]=10;\nmov[ecx+edx*4+00422000h],0Ah\n20\n请回答下列问题。\n(1）第20条指令的虚拟地址是多少?\n(2）已知第2条jmp和第7条jge都是跳转指令，其操作码分别是EBH和7DH，跳转目标地址\n分别为00401084H和004010BCH，这两条指令分别采用什么寻址方式？请给出第2条指令\njmp的跳转目标地址计算过程。\n(3）已知第19条mov指令的功能是“a[i]j]←10\"，其中ecx和edx为寄存器名，00422000H是\n数组a的首地址，指令中源操作数采用什么寻址方式？已知edx中存放的是变量j，ecx中存\n放的是什么？根据该指令的机器码判断计算机M采用的是大端还是小端方式？\n(4）第1次执行第19条指令时，取指令过程中是否会发生缺页异常？为什么？","options":[],"hasFigure":false,"source":"ocr"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"（7分)现要求学生使用swap指令和布尔型变量lock实现临界区互斥。lock为线程间共享的变量。\nlock的值为TRUE时线程不能进入临界区，为FALSE时线程能够进入临界区。某同学编写的实\n现临界区互斥的伪代码如下图(a)所示。\n请回答下列问题。\n(1）图(a)的伪代码中哪些语句存在错误？将其改为正确的语句（不增加语句条数)。\n(2）图(b)给出了交换两个变量值的函数newSwapO的代码，是否可以用函数调用语句\n“newSwap(&key,&lock)”代替指令“swapkey,lock”以实现临界区互斥？为什么？\n某同学编写的伪代码\nnewSwap(）的代码\nboollock=FALSE;\n/共享变量\nvoid newSwap(bool *a,bool *b){\nbool temp = *a;\nbool key=TRUE;\n*a=*b;\nif (key ==TRUE)\n；进入区\n*b = temp ;\nswapkey，lock；//交换key和lock的值！\n临界区；\nlock=TRUE\n退出区\n(a)\n(b)","options":[],"hasFigure":true,"source":"ocr"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"(8分)进程P通过执行系统调用从键盘接收一个字符的输人。已知此过程中与进程P相关的操\n作包括：①将进程P插人就绪队列；②将进程P插人阻塞队列；③将字符从键盘控制器读人系\n统缓冲区；④启动键盘中断处理程序；③进程P从系统调用返回；用户在键盘上输人字符。\n以上编号①～6仅用于标记操作，与操作的先后顺序无关。请回答下列问题。\n(1）按照正确的操作顺序，操作①的前一个和后一个操作分别是上述操作中的哪一个？操作6\n的后一个操作是上述操作中的哪一个？\n(2）在上述哪个操作之后，CPU一定从进程P切换到其他进程？在上述哪个操作之后CPU调度\n程序才能选中进程P执行？\n(3）完成上述哪个操作的代码属于键盘驱动程序？\n(4）键盘中断处理程序执行时，进程P处于什么状态？CPU处于内核态还是用户态？","options":[],"hasFigure":false,"source":"ocr"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":8,"stem":"（9分)某网络拓扑如下图所示，主机H登录到FTP服务器后，向服务器上传-一个大小为18000B\n的文件F。假设H为传输F建立数据连接时，选择的初始序号为100，MSS=1000B，拥塞控制\n的初始阈值是4MSS，RTT=10ms，忽略TCP的传输时延；在F的传输过程中，H均以MSS段\n向服务器发送数据，且未发生差错、丢包和乱序现象。\nInternet\nFTP服务器\nH\n交换机\n路由器\n请回答下列问题。\n(1）FTP的控制连接是持久的还是非持久的？FTP的数据连接是持久的还是非持久的？H登录\nFTP服务器时，建立的TCP连接是控制连接还是数据连接？\n(2）H通过数据连接发送F时，F的第一个字节序号是多少？在断开数据连接的过程中，FTP服\n务器发送的第二次挥手ACK段的确认序号是多少？\n(3）H通过数据连接发送F的过程中，当H收到确认序号为2101的确认时，H的拥塞窗口调整\n为多少？收到确认序号为7101的确认段时，H的拥塞窗口调整为多少？\n(4）H从请求建立数据连接开始，到确认F已被服务全部接收为止，至少需要多长时间？在这期\n间应用层数据的平均发送速率是多少？","options":[],"hasFigure":true,"source":"ocr"}]},{"year":2024,"title":"2024 年全国硕士研究生招生考试 计算机学科专业基础试题（回忆版）","totalScore":150,"timeLimit":180,"hasPdf":false,"edition":"回忆版","note":"2024 为回忆版：第 19、21、22、23 题选项暂缺；仅提供题目文字，不提供原卷下载。","questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"一个带头结点的链表 L，指针 p 指向链表 L 中间的某个结点（非首尾结点）。对于以下代码段：\nq = p->next; p->next = q->next; q->next = L->next; L->next = q;\n其功能是（ ）。","options":[{"key":"A","text":"将 p 指向结点移到 q 指向结点后"},{"key":"B","text":"将 q 指向结点移到 p 指向结点后"},{"key":"C","text":"将 p 指向结点插入头结点后"},{"key":"D","text":"将 q 指向结点插入头结点后"}],"hasFigure":false,"source":"ocr-manual"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"中缀表达式 x+y*(z-u)/v 对应的后缀表达式是（ ）。","options":[{"key":"A","text":"xyzu-*v/+"},{"key":"B","text":"xuzu-v*+"},{"key":"C","text":"+x/*y-zuv"},{"key":"D","text":"+x*y/-zuv"}],"hasFigure":false,"source":"ocr-manual"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"p、q、v 都是二叉树 T 中的结点，其中结点 v 有两个孩子结点，二叉树 T 的中序遍历为：…, p, v, q, …，则（ ）。","options":[{"key":"A","text":"p 没有右孩子，q 没有左孩子"},{"key":"B","text":"p 没有右孩子，q 有左孩子"},{"key":"C","text":"p 有右孩子，q 没有左孩子"},{"key":"D","text":"p 有右孩子，q 有左孩子"}],"hasFigure":false,"source":"ocr-manual"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知如下邻接多重表，请问顶点 b、d 的度分别是（ ）。","options":[{"key":"A","text":"2, 4"},{"key":"B","text":"4, 2"},{"key":"C","text":"2, 3"},{"key":"D","text":"3, 2"}],"hasFigure":true,"source":"ocr-manual"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"以下存储结构中，不适用于折半查找的是（ ）。\nI. 有序链表\nII. 无序数组\nIII. 有序静态链表\nIV. 无序静态链表","options":[{"key":"A","text":"仅 I 和 III"},{"key":"B","text":"仅 II 和 IV"},{"key":"C","text":"仅 II、III、IV"},{"key":"D","text":"I、II、III、IV"}],"hasFigure":false,"source":"ocr-manual"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"KMP 算法使用修正后的 next 数组进行模式匹配，模式串 s = “aabaab”，主串中某个字符失配时，s 右滑最长距离为（ ）。","options":[{"key":"A","text":"5"},{"key":"B","text":"4"},{"key":"C","text":"3"},{"key":"D","text":"2"}],"hasFigure":false,"source":"ocr-manual"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"一棵二叉搜索树如下图所示，图中 K1、K2、K3 表示结点中保存的关键字，图中三角形表示子树。则图中子树 T 中任意结点保存的关键字 X 满足（ ）。","options":[{"key":"A","text":"X < K1"},{"key":"B","text":"X > K2"},{"key":"C","text":"K1 < X < K3"},{"key":"D","text":"K3 < X < K2"}],"hasFigure":true,"source":"ocr-manual"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"使用快速排序算法对含 N 个元素的数组 M 进行排序，若第一趟排序将除枢轴外的 N-1 个元素划分为 P 和 Q 两个部分，则下列叙述中，正确的是（ ）。","options":[{"key":"A","text":"P 和 Q 块间有序"},{"key":"B","text":"P 和 Q 均块内有序"},{"key":"C","text":"P 和 Q 的元素个数大致相等"},{"key":"D","text":"P 和 Q 中均不存在相等的元素"}],"hasFigure":false,"source":"ocr-manual"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"大根堆初始序列为：28, 22, 20, 19, 8, 12, 15, 5，对该堆进行两次删除操作后，得到的新堆是（ ）。","options":[{"key":"A","text":"20, 19, 15, 12, 8, 5"},{"key":"B","text":"20, 19, 15, 5, 8, 12"},{"key":"C","text":"20, 19, 12, 15, 8, 5"},{"key":"D","text":"20, 19, 8, 12, 15, 5"}],"hasFigure":false,"source":"ocr-manual"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对如下三个升序序列：{3,5}、{7,9}、{6}，进行二路归并排序，关键字的比较次数是（ ）。","options":[{"key":"A","text":"3"},{"key":"B","text":"4"},{"key":"C","text":"5"},{"key":"D","text":"6"}],"hasFigure":false,"source":"ocr-manual"},{"number":11,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"外部排序使用败者树进行升序归并，“冠军”结点保存的是（ ）。","options":[{"key":"A","text":"最大关键字"},{"key":"B","text":"最大关键字所在的归并段号"},{"key":"C","text":"最小关键字"},{"key":"D","text":"最小关键字所在的归并段号"}],"hasFigure":false,"source":"ocr-manual"},{"number":12,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"执行如下 C 语言代码之后，变量 j 的值是（ ）。\nint i = 32777;\nshort si = i;\nint j = 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次冲突时探测的地址。Hk=(H0+k^2)%11。请回答下列问题：\n（1）画出 HT，计算装填因子。\n（2）查找关键字 14 时的关键字比较序列。\n（3）查找关键字 8 失败时的哈希地址。","options":[],"hasFigure":false,"source":"ocr-manual"},{"number":43,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":13,"stem":"假定计算机 M 字长为 32 位，按字节编址，采用 32 位定长指令字，指令 add、slli 和 lw 的格式、编码和功能说明如图 43(a) 所示。\n题 43(b) 图给出了计算机 M 的部分数据通路及控制信号，其中 A 和 B 分别表示从通用寄存器 rs1 和 rs2 中读出的内容，IR[31:20] 表示指令寄存器中的高 12 位；控制信号 Ext 为 0、1 时扩展器分别实现零扩展、符号扩展；ALUctr 为 000、001、010 时 ALU 分别执行加、减、逻辑左移运算。\n请回答下列问题：\n（1）M 最多有几个寄存器？为什么 shamt 占 5 位？\n（2）执行 add 指令时，控制信号 ALUBsrc 的取值应该是什么？若 rs1 和 rs2 寄存器内容分别是 87654321H 和 98765432H，则 add 指令执行后，ALU 输出端 F、OF 和 CF 的结果分别是什么？若设 add 指令处理的是无符号整数，则应根据哪个标志判断是否溢出？\n（3）执行 slli 指令时，控制信号 Ext 的取值可以是 0 也可以是 1，为什么？\n（4）执行 lw 指令时，控制信号 Ext、ALUctr 的取值分别是什么？\n（5）若一条指令的机器码是 A040A103H，则该指令一定是 lw 指令，为什么？\n（6）若执行该指令时，R[01H]=FFFFA2D0H，则所读取数据的存储地址是多少？","options":[],"hasFigure":true,"source":"ocr-manual"},{"number":44,"type":"SUBJECTIVE","subject":"co","subjectName":"计算机组成原理","score":10,"stem":"对于题 43 中的计算机 M，C 语言程序中包含的语句“sum+=a[i]”，在 M 中对应的指令序列 S 如下：\nslli r4, r2, 2        // R[r4] ← R[r2] << 2\nadd  r4, r3, r4        // R[r4] ← R[r3] + R[r4]\nlw   r5, 0(r4)         // R[r5] ← M[R[r4] + 0]\nadd  r1, r1, r5        // R[r1] ← R[r1] + R[r5]\n其中，i、sum、数组 a 都为 int 型，r1～r5 的寄存器编号为 01H～05H。请回答下列问题：\n（1）a 的首地址、变量 i、变量 sum 存储的寄存器编号是？\n（2）该系统采用小端方式、页式存储，页大小为 4KB。执行第 1 条指令时，i=5，r1=00001332H，r3=0013DFF0H，存储单元内容如图所示。执行 sum+=a[i] 后，a[i] 的地址为？a[i] 和 sum 的机器数为？a[i] 所在页的页号为？此次执行中，数组 a 至少存放在几页中？\n（3）slli r4, r2, 2 的机器码是？若 a 改为 short 型，则 slli 指令的汇编形式应该是？","options":[],"hasFigure":true,"source":"ocr-manual"},{"number":45,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":7,"stem":"某计算机采用虚拟页式存储管理，虚拟地址、物理地址为 32 位，页表项大小为 4B，页面大小为 4MB。虚拟地址结构如下：页号（10 位）| 页内偏移量（22 位）。\n进程 P 的页表起始虚拟地址为 B8C00000H，页表被装载到物理地址为 65400000H 开始的连续空间。请回答下列问题：\n（1）进程 P 访问虚拟地址 12345678H 时发生缺页，经缺页异常处理和 MMU 地址转换之后，得到的物理地址为 BAB45678H。此次缺页异常处理过程中，需要为所缺页面分配页框，并更新相应的页表项，则该页表项的虚拟地址、物理地址分别是？该页表项的页框号更新后的值是什么？\n（2）进程 P 的页表所在页的页号是多少？该页对应的页表项的虚拟地址是多少？该页表项中的页框号是多少？","options":[],"hasFigure":false,"source":"ocr-manual"},{"number":46,"type":"SUBJECTIVE","subject":"os","subjectName":"操作系统","score":8,"stem":"计算机系统中的进程之间往往需要相互协作以完成一个任务。在某网络系统中，缓冲区 B 用于存放一个数据分组，对 B 的操作有 C1、C2 和 C3。C1 将一个数据分组写入 B 中，C2 从 B 中读出一个数据分组，C3 对 B 中的数据分组进行修改。要求 B 为空时才能执行 C1，B 非空时才能执行 C2 和 C3。请回答下列问题：\n（1）假设进程 P1 和 P2 均需执行 C1，实现 C1 的代码是否为临界区？为什么？\n（2）假设 B 初始为空，进程 P1 执行 C1 一次，进程 P2 执行 C2 一次。请定义尽可能少的信号量，并用 wait()、signal() 操作描述进程 P1、P2 之间的同步或互斥关系，说明所用信号量的作用及初值。\n（3）假设 B 初始不为空，进程 P1 和 P2 各执行 C3 一次，请定义尽可能少的信号量，并用 wait()、signal() 操作描述进程 P1、P2 之间的同步或互斥关系，说明所用信号量的作用及初值。","options":[],"hasFigure":false,"source":"ocr-manual"},{"number":47,"type":"SUBJECTIVE","subject":"cn","subjectName":"计算机网络","score":9,"stem":"AS1 运行内部网关协议 RIP，网络拓扑如图 47 所示。请回答下列问题：\n（1）AS4 规模较大，自治系统内任意两个主机间通信，经过路由器数量可能超过 20 个。若仅有 RIP 和 OSPF 内部网关协议供选择，则 AS4 应选择哪个协议？\n（2）AS3 规模较小，自治系统内任意两个主机间通信，经过路由器数不超过 15 个；若 AS3 中的某主机向本自治系统另一主机发送 1 个 IP 分组，为确保该 IP 分组能正常接收，则该 IP 分组的初始 TTL 值应至少设置为多少？\n（3）设 AS1 中的路由器同一时刻启动，启动后立即构建并交换初始距离向量，之后每隔 30s 交换一次最新的距离向量。则从交换初始距离向量时刻算起，R11～R16 到达网络 210.2.4.0/24 的正确路由，至少需多长时间？\n（4）R44 向 R13 通告到达网络 136.5.16.0/20 路由时，由 BGP 协议哪类会话完成？通过哪个 BGP 报文通告？R13 通过 BGP 协议的哪类会话将该网络可达性信息通告给 R14 和 R15？\n（5）若 R14 和 R15 均收到分别由 R11、R12、R13 通告的到达网络 136.5.16.0/20 的可达性信息，则在无策略约束情况下，R14 和 R15 更新路由表后，各自路由表中到达网络 136.5.16.0/20 路由的下一跳分别是什么（用路由器名称表示）？","options":[],"hasFigure":true,"source":"ocr-manual"}],"questionCount":47,"choiceCount":40,"subjectiveCount":7},{"year":2025,"title":"2025 年全国硕士研究生招生考试 计算机学科专业基础试题（选择题回忆版）","totalScore":150,"timeLimit":180,"hasPdf":false,"edition":"回忆版","note":"2025 为选择题回忆版：已收录第 1–32 题，第 33–40 题暂缺；仅提供题目文字，不提供原卷下载。","questions":[{"number":1,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列程序段的时间复杂度是（ ）。\nint count = 0, i, j;\nfor (i = 1; i * i <= n; i++)\n    for (j = 1; j <= i; j++)\n        count++;","options":[{"key":"A","text":"O(log n)"},{"key":"B","text":"O(n)"},{"key":"C","text":"O(n log n)"},{"key":"D","text":"O(n^2)"}],"hasFigure":false,"source":"ocr-manual"},{"number":2,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知算法 A 用于检查字符串中各类括号是否匹配，A 执行过程中使用初始为空的栈保存遇到的括号。若栈的容量是 3，则下列选项中，A 不能处理的是（ ）。","options":[{"key":"A","text":"(a+[b+(c+d)/e]+f)+g-h"},{"key":"B","text":"[a*((b+c)/(d-e)+f/g)-h]"},{"key":"C","text":"[a*(b-(c-d)*e/(f+g))-h]"},{"key":"D","text":"[a-(b+[c*(d+e)-f]+g+h)]"}],"hasFigure":false,"source":"ocr-manual"},{"number":3,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"若二叉树的结点值均为正整数，采用顺序存储方式保存在数组 R 中，用 -1 表示结点不存在，则下列数组中，不能表示一棵二叉树的是（ ）。","options":[{"key":"A","text":"R[] = {20, 15, 40, -1, -1, 35}"},{"key":"B","text":"R[] = {15, 40, 10, 18, 35, -1, -1}"},{"key":"C","text":"R[] = {15, 40, 10, -1, -1, -1, 12}"},{"key":"D","text":"R[] = {17, 20, 35, -1, 18, 45, -1, -1, 19, 27}"}],"hasFigure":false,"source":"ocr-manual"},{"number":4,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列关于二叉树及森林的叙述中，正确的是（ ）。","options":[{"key":"A","text":"完全二叉树中不存在度为 1 的结点"},{"key":"B","text":"任意一个森林都可以转换为一棵二叉树"},{"key":"C","text":"二叉树的分支结点个数比叶结点个数少"},{"key":"D","text":"表达式树的根中保存的是最先计算的运算符"}],"hasFigure":false,"source":"ocr-manual"},{"number":5,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"设字符集 S 包含 7 个字符，各字符出现的频次分别为 2, 3, 4, 6, 8, 10, 11。现为 S 中的各字符构造哈夫曼编码，编码长度不小于 3 的字符个数是（ ）。","options":[{"key":"A","text":"2"},{"key":"B","text":"3"},{"key":"C","text":"4"},{"key":"D","text":"5"}],"hasFigure":false,"source":"ocr-manual"},{"number":6,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列关于图的叙述中，正确的是（ ）。","options":[{"key":"A","text":"有向图必存在入度为 0 的顶点"},{"key":"B","text":"有向无环图的拓扑有序序列存在且唯一"},{"key":"C","text":"各顶点的度均大于等于 2 的无向图必有回路"},{"key":"D","text":"可用 BFS 算法求出带权图中每一对顶点间的最短路径"}],"hasFigure":false,"source":"ocr-manual"},{"number":7,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"已知查找表中有 400 个元素，查找元素的概率相同，采用分块查找法且均匀分块。若采用顺序查找法确定元素所在块，且块内也用顺序查找法，为使效率最高，每块包含元素个数应为（ ）。","options":[{"key":"A","text":"8"},{"key":"B","text":"10"},{"key":"C","text":"20"},{"key":"D","text":"25"}],"hasFigure":false,"source":"ocr-manual"},{"number":8,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"给定 7 个不同的关键字，能够构造的不同 4 阶 B 树的个数最多是（ ）。","options":[{"key":"A","text":"7"},{"key":"B","text":"8"},{"key":"C","text":"9"},{"key":"D","text":"10"}],"hasFigure":false,"source":"ocr-manual"},{"number":9,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列关于散列法处理冲突的叙述中，正确的是（ ）。","options":[{"key":"A","text":"只要散列表不满，线性探查再散列一定能找到一个空闲位置"},{"key":"B","text":"只要散列表不满，二次探查再散列一定能找到一个空闲位置"},{"key":"C","text":"线性探查再散列处理的冲突，一定是发生在同义词之间的冲突"},{"key":"D","text":"二次探查再散列处理的冲突，一定是发生在非同义词之间的冲突"}],"hasFigure":false,"source":"ocr-manual"},{"number":10,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"下列排序算法中，最坏情况下元素移动最少的是（ ）。","options":[{"key":"A","text":"起泡排序"},{"key":"B","text":"直接插入排序"},{"key":"C","text":"快速排序"},{"key":"D","text":"简单选择排序"}],"hasFigure":false,"source":"ocr-manual"},{"number":11,"type":"CHOICE","subject":"ds","subjectName":"数据结构","score":2,"stem":"对含 9 个关键字的初始序列进行排序，若序列的变化情况如下所示。\n初始序列：5, 25, 40, 30, 10, 20, 45, 15, 35；\n第 1 趟排序后的序列：5, 10, 20, 30, 15, 35, 45, 25, 40；\n第 2 趟排序后的序列：5, 10, 15, 25, 20, 30, 40, 35, 45。\n则下列排序算法中，采用的是（ ）。","options":[{"key":"A","text":"希尔排序"},{"key":"B","text":"基数排序"},{"key":"C","text":"归并排序"},{"key":"D","text":"折半插入排序"}],"hasFigure":false,"source":"ocr-manual"},{"number":12,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"在 32 位计算机上执行下列 C 语言代码。\nshort si = -32767;\nunsigned int ui = si;\n则 ui 的值为（ ）。","options":[{"key":"A","text":"2^15 − 1"},{"key":"B","text":"2^15 + 1"},{"key":"C","text":"2^32 − 2^15 − 1"},{"key":"D","text":"2^32 − 2^15 + 1"}],"hasFigure":false,"source":"ocr-manual"},{"number":13,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"已知 float 型变量用 IEEE 754 单精度浮点数格式表示。若 float 型变量 x 的机器数为 4730 0000H，则 x 的值为（ ）。","options":[{"key":"A","text":"0.375×2^14"},{"key":"B","text":"1.375×2^14"},{"key":"C","text":"0.375×2^15"},{"key":"D","text":"1.375×2^15"}],"hasFigure":false,"source":"ocr-manual"},{"number":14,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"假设 8 位字长的计算机中，两个带符号整数 x 和 y 的补码表示分别为 [x]补 = A3H，[y]补 = 75H，则通过补码加减运算器得到的 x-y 的值及 OF 标志分别为（ ）。","options":[{"key":"A","text":"24, 0"},{"key":"B","text":"24, 1"},{"key":"C","text":"46, 0"},{"key":"D","text":"46, 1"}],"hasFigure":false,"source":"ocr-manual"},{"number":15,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某 32 位计算机按字节编址，采用小端方式存放数据，编译器按边界对齐方式为下列 C 语言结构型数组变量 employee 分配储存空间。\nstruct record {\n    int id;\n    char name[10];\n    int salary;\n} employee[200];\n若数组 employee 的起始地址为 0000 A0B0H，employee[1].id 的机器数为 1234 5678H，则 56H 所在存储单元的地址是（ ）。","options":[{"key":"A","text":"0000 A0C3H"},{"key":"B","text":"0000 A0C4H"},{"key":"C","text":"0000 A0C5H"},{"key":"D","text":"0000 A0C6H"}],"hasFigure":false,"source":"ocr-manual"},{"number":16,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列选项中，由指令集体系结构（ISA）规定的是（ ）。","options":[{"key":"A","text":"是否采用阵列乘法器"},{"key":"B","text":"是否采用定长指令字格式"},{"key":"C","text":"是否采用微程序控制器"},{"key":"D","text":"是否采用单总线数据通路"}],"hasFigure":false,"source":"ocr-manual"},{"number":17,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列关于 RISC 的叙述中，错误的是（ ）。","options":[{"key":"A","text":"多采用硬连线方式实现控制器"},{"key":"B","text":"通常采用 Load/Store 型指令设计风格"},{"key":"C","text":"难以采用流水线数据通路实现微架构"},{"key":"D","text":"多采用寄存器传递过程调用时的参数"}],"hasFigure":false,"source":"ocr-manual"},{"number":18,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列关于 CPU 和 CPU 时钟周期的叙述中，错误的是（ ）。","options":[{"key":"A","text":"不同类型指令的 CPI 可能不一样"},{"key":"B","text":"程序的 CPI 与 Cache 缺失率无关"},{"key":"C","text":"单周期 CPU 的时钟周期以最耗时指令所用的时间为准"},{"key":"D","text":"流水线 CPU 的时钟周期以最长流水段所用时间为准"}],"hasFigure":false,"source":"ocr-manual"},{"number":19,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列关于 CPU 中的数据通路和控制器的叙述中，错误的是（ ）。","options":[{"key":"A","text":"通用寄存器组中应该包含程序计数器"},{"key":"B","text":"控制器中一定包含指令操作码的译码电路"},{"key":"C","text":"单周期 CPU 中的控制器比多周期 CPU 中的更简单"},{"key":"D","text":"流水线 CPU 需解决数据相关和控制相关等冒险问题"}],"hasFigure":false,"source":"ocr-manual"},{"number":20,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"某处理器总线采用同步、并行传输方式，每个总线时钟周期传送 4 次数据（quadpumped 技术），若该总线的工作频率为 1333 MHz（实际单位是 MT/s，表示每秒传送 1333M 次），总线宽度为 64 位，则总线带宽约为（ ）。","options":[{"key":"A","text":"10.66 GB/s"},{"key":"B","text":"42.66 GB/s"},{"key":"C","text":"85.31 GB/s"},{"key":"D","text":"341.25 GB/s"}],"hasFigure":false,"source":"ocr-manual"},{"number":21,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列设备中，适合采用 DMA 输入/输出方式的是（ ）。\nI. 键盘\nII. 网卡\nIII. 固态硬盘\nIV. 针式打印机","options":[{"key":"A","text":"仅 I、II"},{"key":"B","text":"仅 II、III"},{"key":"C","text":"仅 II、IV"},{"key":"D","text":"仅 III、IV"}],"hasFigure":false,"source":"ocr-manual"},{"number":22,"type":"CHOICE","subject":"co","subjectName":"计算机组成原理","score":2,"stem":"下列选项中，会触发外部中断请求的事件是（ ）。","options":[{"key":"A","text":"DMA 传送结束"},{"key":"B","text":"总线事务结束"},{"key":"C","text":"页故障的处理结束"},{"key":"D","text":"执行断点指令"}],"hasFigure":false,"source":"ocr-manual"},{"number":23,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"在采用页式虚拟存储管理方式的系统中，当发生上下文切换时，下列寄存器中操作系统不需要更新的是（ ）。","options":[{"key":"A","text":"通用寄存器"},{"key":"B","text":"页表基址寄存器"},{"key":"C","text":"程序计数器"},{"key":"D","text":"内核中断向量表基址寄存器"}],"hasFigure":false,"source":"ocr-manual"},{"number":24,"type":"CHOICE","subject":"os","subjectName":"操作系统","score":2,"stem":"关于虚拟化技术，下列叙述错误的是（ 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