谭浩强【C语言程序设计】第九章习题详解

1.定义一个结构体变量（包括年、月、日）。计算该日在本年中是第几天，注意闰年问题。

#include struct date{int year;int month;int day;}d;int main(){int day[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };printf("请输入年 月 日：\n");scanf("%d%d%d", &d.year, &d.month, &d.day);int days = 0;for (int i = 1; i  2){days++;}}printf("该日在%d年%d月%d日是第%d天。\n", d.year, d.month, d.day, days);return 0;}

2.写一个函数days，实现第1题的计算。由主函数将年、月、日传递给 days函数，计算后将日子数传回主函数输出。

#include struct date{int year;int month;int day;}d;int days(int year, int month, int day){int day_tab[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };int day_sum = 0;for (int i = 1; i  2){day_sum++;}}return day_sum;}int main(){printf("请输入年 月 日：\n");scanf("%d%d%d", &d.year, &d.month, &d.day);int day_sum = days(d.year, d.month, d.day);printf("该日在%d年%d月%d日是第%d天。\n", d.year, d.month, d.day, day_sum);return 0;}

3.编写一个函数 print，打印一个学生的成绩数组，该数组中有5个学生的数据记录，每个记录包括 num, name, score［3］，用主函数输入这些记录，用 print函数输出这些记录。

#include #define N 5struct student{char num[6];char name[8];int score[3];}stu[N];void print(struct student stu[6]){printf("\n num name score1score2score3\n");for (int i = 0; i < N; i++){printf("%4s%6s", stu[i].num, stu[i].name);for (int j = 0; j < 3; j++){printf("%8d", stu[i].score[j]);}printf("\n");}}int main(){for (int i = 0; i \n", i + 1);printf("num：");scanf("%s", stu[i].num);printf("name：");scanf("%s", stu[i].name);for (int j = 0; j < 3; j++){printf("score %d：", j + 1);scanf("%d", &stu[i].score[j]);}printf("\n");}print(stu);return 0;}

4.在第3题的基础上，编写一个函数 input，用来输入5个学生的数据记录。

#include #define N 5struct student{char num[6];char name[8];int score[3];}stu[N];void print(struct student stu[6]){printf("\n num name score1score2score3\n");for (int i = 0; i < N; i++){printf("%4s%6s", stu[i].num, stu[i].name);for (int j = 0; j < 3; j++){printf("%8d", stu[i].score[j]);}printf("\n");}}void input(struct student stu[]){for (int i = 0; i \n", i + 1);printf("num：");scanf("%s", stu[i].num);printf("name：");scanf("%s", stu[i].name);for (int j = 0; j < 3; j++){printf("score %d：", j + 1);scanf("%d", &stu[i].score[j]);}printf("\n");}}int main(){input(stu);print(stu);return 0;}

5.有10个学生，每个学生的数据包括学号、姓名、3门课程的成绩，从键盘输入10个学生数据，要求输出3门课程总平均成绩，以及最高分的学生的数据（包括学号、姓名、3门课程成绩、平均分数）。

#include #define N 3struct student{char num[6];char name[8];float score[3];float avg;}stu[N];int main(){for (int i = 0; i \n", i + 1);printf("num：");scanf("%s", stu[i].num);printf("name：");scanf("%s", stu[i].name);for (int j = 0; j < 3; j++){printf("score %d：", j + 1);scanf("%f", &stu[i].score[j]);}}//计算float average = 0, max = 0;int maxi = 0;float sum = 0;for (int i = 0; i < N; i++){sum = 0;for (int j = 0; j  max)//找分数最高者{max = sum;maxi = i;//将此学生的下标保存在maxi}}average /= N;//计算总平均分数printf("\n numnamescore1 score2 score3average\n");for (int i = 0; i < N; i++){printf("%3.2s%6.2s", stu[i].num, stu[i].name);for (int j = 0; j < 3; j++){printf("%8.2f", stu[i].score[j]);}printf("%8.2f\n", stu[i].avg);}printf("\naverage=%5.2f\n", average);printf("最高成绩是：student %s, %s\n", stu[maxi].num, stu[maxi].name);printf("他的成绩是：%6.2f,%6.2f,%6.2f,average:%5.2f\n", stu[maxi].score[0], stu[maxi].score[1], stu[maxi].score[2], stu[maxi].avg);return 0;}

6.13个人围成一圈，从第1个人开始顺序报号1，2，3。凡报到3者退出圈子。找出最后留在圈子中的人原来的序号。要求用链表实现。

#include #define NUM 13//定义节点typedef struct people{int num;struct people* next;}people;int main(){//定义包含13个人的数据people arr[NUM];//建立环状链表people* head = arr;for (int i = 0; i num = i + 1;head->next = &arr[i + 1];head = head->next;}//构成环状链表arr[NUM - 1].next = arr;//开始报数int count = NUM;//从1开始报数int i = 1;head = arr;while (count > 1){//1.判断是否已经退出if (head->next == 0){//跳过此人head = head->next;continue;}if (i == 3){//当前此人需要退出printf("第%d个人退出\n", head->num);head->num = 0;count--;}//继续报号i++;head = head->next;//判断报号是否大于3if (i > 3){i = 1;}}//找出编号不为0的人while (head->num == 0){//找下一个人head = head->next;if (head->num != 0){printf("没有退出的人为：%d\n", head->num);}}return 0;}

7. 在第9章例9.9和例9.10的基础上，写一个函数del，用来删除动态链表中指定的结点。

#include #include typedef struct node{int num;struct node* next;}node;//创建链表：创建一个含有n个节点的链表，返回头节点的指针node* creat(int n){//创建一个头节点node* head = (node*)malloc(sizeof(node));head->num = 0;head->next = NULL;node* p = head;//创建数据为1~n的节点for (int i = 1; i num = i;newNode->next = NULL;p->next = newNode;p = p->next;}return head;}//打印链表数据void printNode(node* head){//第一个数据为head->nextnode* p = head->next;while (p != NULL){printf("node %d\n", p->num);p = p->next;}}void del(node* head, int val){node* prev = head;node* p = head;//遍历链表，找到需要删除的节点while (p != NULL){if (p->num == val){prev->next = p->next;free(p);break;}else{prev = p;p = p->next;}}}int main(){node* head = creat(10);int n;printf("当前链表的所有节点：\n");printNode(head);printf("请输入需要删除的节点编号：\n");scanf("%d", &n);del(head, n);//删除之后链表的节点printf("删除之后链表的节点：\n");printNode(head);return 0;}

8. 写一个函数 insert，用来向一个动态链表插入结点。

#include #include typedef struct node{int num;struct node* next;}node;void insert(node* p, int n){//创建节点node* newNode = (node*)malloc(sizeof(node));newNode->num = n;//链接newNode->next = p->next;p->next = newNode;}node* creat(int n){//创建含有n个有效数据的节点//创建一个带头的链表node* head = (node*)malloc(sizeof(node));head->num = 0;head->next = NULL;node* p = head;//创建有效数据的节点for (int i = 1; i num = i;newNode->next = NULL;p->next = newNode;p = p->next;}return head;}void printNode(node* head){//从第一个有效数据开始打印node* p = head->next;while (p != NULL){printf("node %d\n", p->num);p = p->next;}}int main(){int n;node* head = creat(10);printf("未插入数据之前的原始列表：\n");printNode(head);printf("请输入需要插入的数据：\n");scanf("%d", &n);insert(head, n);printf("插入数据之后的链表：\n");printNode(head);return 0;}

9.综合本章例9.9（建立链表的函数 creat）、例9.10（输出链表的函数 print）和本章习题第7题（删除链表中结点的函数dei）、第8题（插入结点的函数 insert），再编写一个主函数，先后调用这些函数。用以上5个函数组成一个程序，实现链表的建立、输出、删除和插入，在主函数中指定需要删除和插入的结点的数据。

#include #include #define CNT 3//定义节点typedef struct node{int num;struct node* next;}node;//创建链表：从控制台输入数据node* creat(){//首先创建一个头节点，不存放有效数据node* head = (node*)malloc(sizeof(node));head->next = NULL;head->num = 0;node* p = head;printf("创建一个含有%d个数据的单链表\n", CNT);printf("请输入%d个数据：", CNT);for (int i = 0; i num = n;newNode->next = NULL;//链接p->next = newNode;p = p->next;}return head;}//打印链表void printNode(node* head){node* p = head->next;while (p != NULL){printf("node: %d\n", p->num);p = p->next;}}//删除节点void del(node* head, int val){//遍历链表，找到待删除的位置node* p = head->next;node* prev = head;while (p != NULL){if (p->num == val){prev->next = p->next;free(p);break;}else{prev = p;p = p->next;}}}//插入节点void insert(node* p, int val){//给p节点的后面插入新的数据node* newNode = (node*)malloc(sizeof(node));newNode->num = val;newNode->next = NULL;newNode->next = p->next;p->next = newNode;}int main(){printf("创建链表：\n");node* head = creat();printf("创建链表结束：\n");printf("初始链表：\n");printNode(head);printf("请输入需要插入的数据：\n");int n;scanf("%d", &n);insert(head, n);printf("插入数据: %d之后，链表的所有数据：\n",n);printNode(head);printf("请输入需要删除的数据：\n");scanf("%d", &n);del(head, n);printf("删除数据：%d之后，链表的所有数据：\n", n);printNode(head);return 0;}

10.已有 a，b两个链表，每个链表中的结点包括学号、成绩。要求把两个链表合并，按学号升序排列。

#include #include #define NUM 5typedef struct node{int num;float score;struct node* next;}node;node* creat(){printf("请输入%d个数据：学号 成绩\n", NUM);node* head = NULL;//链表的表尾node* tail = NULL;for (int i = 0; i num = num;newNode->score = score;newNode->next = NULL;//插入到已有链表//判断当前链表是否为空if (head == NULL){head = tail = newNode;}else{//把新的节点插入到尾节点后面tail->next = newNode;tail = newNode;}}return head;}//合并，排序两个链表node* mergeList(node* a, node* b){//合并node* head = a;while (head->next != NULL){head = head->next;}head->next = b;head = a;//prev：未排序的第一个节点node* prev = a;//排序，选择排序while (prev->next != NULL){//每次从未排序的节点中选择一个学号最小的//放在第一个未排序节点的位置node* cur = prev->next;while (cur){if (prev->num > cur->num){//把学号最小的数据往前移动int num = prev->num;float score = prev->score;prev->num = cur->num;prev->score = cur->score;cur->num = num;cur->score = score;}cur = cur->next;}prev = prev->next;}return head;}void printNode(node* a){while (a != NULL){printf("学号：%d 成绩：%f\n", a->num, a->score);a = a->next;}}int main(){node* a = creat();node* b = creat();printf("链表a的数据：\n");printNode(a);printf("链表b的数据：\n");printNode(b);printf("合并a和b\n");a = mergeList(a, b);printNode(a);return 0;}

11.有两个链表 a和b，设结点中包含学号、姓名。从a链表中删去与b链表中有相同学号的那些结点。

#include #include #define LEN 20typedef struct node{int num;char name[LEN];struct node* next;}node;//返回新链表的表头node* del(node* a, node* b){node* head = a;//遍历b中的每一个节点while (b){//从a的表头开始遍历node* prev = a;node* cur = prev->next;//用头节点和b当前指向的节点进行比较if (prev->num == b->num){prev->next = NULL;//更新表头head = cur;}//用非头节点和b当前指向的节点进行比较else{while (cur){if (cur->num == b->num){//删除当前节点prev->next = cur->next;cur->next = NULL;break;}else{//继续向后遍历prev = cur;cur = cur->next;}}}//处理b的下一个节点b = b->next;}return head;}void printNode(node* head){while (head){printf("%d-->%s\n", head->num, head->name);head = head->next;}}int main(){//建立链表node a[5] = { {3, "zhang"}, {1, "wang"},{15, "li"},{10, "zhou"},{8, "ren"} };node b[3] = { {8, "ren"}, {3, "zhang"}, {10, "zhou"}};for (int i = 0; i < 5; i++){a[i].next = &a[i + 1];}a[4].next = NULL;for (int i = 0; i < 3; i++){b[i].next = &b[i + 1];}b[2].next = NULL;printf("链表a：\n");printNode(a);printf("链表b：\n");printNode(b);node* head = del(a, b);printf("删除之后的链表：\n");printNode(head);return 0;}

12.建立一个链表，每个结点包括：学号、姓名、性别、年龄。输入一个年龄，如果链表中的结点所包含的年龄等于此年龄，则将此结点删去。

#include #define LEN 20typedef struct node{int num;char name[LEN];char gender[LEN];int age;struct node* next;}node;node* del(node* a){int age;printf("请输入需要删除的年龄：\n");scanf("%d", &age);//遍历删除node* prev = NULL;node* cur = a;node* head = a;while (cur){if (cur->age == age){//当前节点需要删除//头节点if (prev == NULL){//更新头节点head = cur->next;}//非头节点else{prev->next = cur->next;}//查看下一个节点cur = cur->next;}else{//当前节点不需要删除prev = cur;cur = cur->next;}}return head;} void printNode(node* head){while (head){printf("%d %s %s %d\n", head->num, head->name, head->gender, head->age);head = head->next;}}int main(){node arr[] = { {1, "wang", "male", 20}, {2, "li", "female", 30}, {3, "zhang", "male", 20}, {4, "li", "female", 18}, {5, "cheng", "male", 20} };//建立链表for (int i = 0; i < 5; i++){arr[i].next = &arr[i + 1];}arr[4].next = NULL;printf("链表的所有数据：\n");printNode(arr);node* head = del(arr);printf("删除之后链表的剩余数据：\n");printNode(head);return 0;}