电大《C++语言程序设计》第1、2、3、4次作业及答案.doc

【精品文档】如有侵权，请联系网站删除，仅供学习与交流电大C+语言程序设计第1、2、3、4次作业及答案.精品文档.第一次作业一、写出下列每个程序运行后的输出结果1. #include<stdio.h>void main()int x=5;switch(2*x-3)case 4:printf("%d ",x);case 7:printf("%d ",2*x+1);case 10:printf("%d ",3*x-1);break;default:printf("%s ","defaultn");printf("%sn","switch end.");2. #include<stdio.h>void main()int i,s=0;for(i=1;i<=6;i+)s+=i*i;printf("s=%dn",s);3. #include<stdio.h>void main()int i,s1=0,s2=0;for(i=0;i<10;i+)if(i%2)s1+=i;else s2+=i;printf("%d %dn",s1,s2);4. #include<stdio.h>void main()int n=10,y=1;while(n-)y+;y+;printf("y=%dn",y);5. #include<stdio.h>void main()int f,f1,f2,i;f1=f2=1;printf("%d %d ",f1,f2);for(i=3;i<=10;i+)f=f1+f2;printf("%d ",f);if(i%5=0)printf("n");f1=f2;f2=f;printf("n");6. #include<stdio.h>#include<math.h>void main()int i,n;for(n=2;n<=20;n+)int temp=(int)sqrt(n);/sqrt(n)求出n的平方根并取整for(i=2;i<=temp;i+)if(n%i=0)break;if(i>temp)printf("%d ",n);printf("n");7. #include<stdio.h>#include<math.h>const int M=20;void main()int i,c2,c3,c5;c2=c3=c5=0;for(i=1;i<=M;i+)if(i%2=0)c2+;if(i%3=0)c3+;if(i%5=0)c5+;printf("%d %d %dn",c2,c3,c5);8. #include<stdio.h>#include<math.h>const int M=20;void main()int i,s;for(i=1,s=0;i<15;i+)if(i%2=0 | i%3=0)continue;printf("%d ",i);s+=i;printf("%dn",s);参考答案：1、答案：11 14 switch end.2、答案：s=91.3、答案：25 20.4、答案：y=21.5、答案：1 1 2 3 58 13 21 34 556、答案：2 3 5 7 11 13 17 197、答案：10 6 48、答案：1 5 7 11 13 37第二次作业一、根据下列每个题目要求编写程序1编写一个函数，函数头格式为“void fun4(char *a , int b)”，分别求出由字符指针a所指向的字符串中包含的每种十进制数字出现的次数，把统计结果保存在数组b的相应元素。2编写一个函数，函数头格式为“double Mean(double aMN , int m , int n)”，要求返回二维数组amn中所有元素的平均值，假定在计算过程是采用变量v存放平均值。3编写一个递归函数“int FF(int a , int n)”，求出数组a中所有元素n个元素之积并返回。4编写一个主函数，利用while循环，求出并显示满足不等式1+1/2+1/3+1/n>5的最小n值。5编写一个主函数，求满足不等式22+42+n2<1000的最大n值，假定分别用i和s为取偶数值和累加值的变量，并限定使用do循环编程。6编写一个主函数，计算并输出n！的值，其中n值由键盘输入。参考答案：1、答案：#include<stdio.h>void fun4(char* a,int b)doif(*a>='0' && *a<='9')b*a-48+;while(*a+);/*void main()char * a="122333444499888"int b10=0;fun4(a,b);for(int i=0;i<10;i+)printf("%d ",bi);2、答案：#include<stdio.h>const int M=2,N=3;double Mean(double aMN, int m,int n )double v=0;for(int i=0;i<m;i+)for(int j=0;j<n;j+)v+=aij;return v/(m*n);/*void main()double a23=1,2,3,4,5,6;printf("%lfn",Mean(a,2,3);3、答案：#include<stdio.h>int FF(int a , int n)int mul=1;if(n=1)mul*=a0;else mul=an-1*FF(a,n-1);return mul;/*void main()int a6=1,2,3,4,5,6;printf("%dn",FF(a,6);4、答案：#include<stdio.h>void main()double sum=0;int n=1;while(true)if(sum + 1/(double)n > 5)break;elsesum += 1/(double)n;n+;printf("%d, %lfn",n,sum);5、答案：#include<stdio.h>void main()int s=0,i=2;dos+=i*i;if(s+(i+2)*(i+2)>=1000)break;else i+=2;while(true);printf("i=%d,s=%d",i,s);6、答案：#include<stdio.h>void main()int s=0,n;printf("请输入n的值：");scanf("%d",&n);for(int i=1;i<=n;i+)s=s*i;printf("n=%d,s=%d",n,s);第三次作业一、写出下列每个程序运行后的输出结果1 程序代码：#include <stdio.h>void SB(char ch) switch(ch) case 'A': case 'a':printf("WW "); break;case 'B': case 'b':printf("GG "); break;case 'C': case 'c':printf("PP "); break;default:printf("BB "); break;void main() char a1 = 'b', a2 = 'C', a3 = 'f'SB(a1); SB(a2); SB(a3); SB('A');printf("n");2 程序代码：#include <stdio.h>#include <stdlib.h>double SD(int a, int b, char op) double x;switch(op) case '+': x = a + b; break;case '-': x = a - b; break;case '*': x = a * b; break;case '/': if(b) x = (double)a/b; else exit(1); break;default: printf("运算符错！n"); exit(1); return x;void main() int x = 20, y = 8;printf("%3.2lf ", SD(x, y, '-');printf("%3.2lf ", SD(x, y, '*');printf("%3.2lfn", SD(x + y, y, '/');3 程序代码：#include <stdio.h>void WF(int x, int y) x = x + y;y = x + y;printf("subs: x, y = %d, %dn", x, y);void main() int x = 18, y = 23;printf("main: x, y = %d, %dn", x, y);WF(x, y);x = 2 * x;printf("main: x, y = %d, %dn", x, y);4 程序代码：#include <stdio.h>#include <string.h>void fun(char ss);void main() char s15 = "567891234"fun(s);printf("%sn", s);void fun(char ss) int i, n = strlen(ss);for(i = 0; i < n / 2; i +) char c = ssi;ssi = ssn - 1 - i;ssn - 1 - i = c;5 程序代码：#include <stdio.h>void InsertSort(int a, int n)int i, j, x;for(i = 1; i < n; i +) / 进行n-1次循环x = ai;for(j = i - 1; j >= 0; j -) / 为x顺序向前寻找合适的插入位置if(x > aj) aj + 1 = aj;else break;aj + 1 = x;void main() int i;int a6 = 20, 15, 32, 47, 36, 28 ;InsertSort(a, 6);for(i = 0; i < 6; i +) printf("%d ", ai);printf("n");6 程序代码：#include <stdio.h>void main() int a8 = 3, 5, 7, 9, 11, 13, 15, 17 ;int i, * p = a;for(i = 0; i < 8; i +) printf("%5d", * p +);if(i + 1) % 4 = 0) printf("n");7 程序代码：#include <stdio.h>int LA(int * a, int n) int i, s = 0;for(i = 0; i < n; i +)s += ai;return s;void main() int a = 5, 10, 15, 20, 25, 30 ;int b = LA(a, 4);int c = LA(a + 2, 3);printf("%d %dn", b, c);8 程序代码：#include <stdio.h>int LB(int * a, int n) int i, s = 1;for(i = 0; i < n; i +) s *= * a +;return s;void main() int a = 1, 2, 3, 4, 2, 4, 5, 2 ;int b = LB(a, 4) + LB(&a3, 4);printf("b=%dn", b);二、写出下列每个函数的功能1 程序代码：int WB(int a, int n, int x) int i;for(i = 0; i < n; i +)if(ai = x) return 1;return 0;2 程序代码：int WC(int a, int n, int k) int c = 0, i;for(i = 0; i < n; i +)if(ai >= k) c +;return c;3 程序代码：#include <stdio.h>#include <stdlib.h>#include <time.h>const int N = 10;int ff(int x, int y) int z;printf("%d + %d = ", x, y);scanf("%d", &z);if(x + y = z) return 1; else return 0;void main() int i, a, b, c = 0;srand(time(0); / 初始化随机数序列for(i = 0; i < N; i +) a = rand() % 20 + 1; / rand()函数产生032767之间的一个随机数b = rand() % 20 + 1;c += ff(a, b);printf("得分：%dn", c * 10);4 * 程序代码：int fun6(int m, int n, int b)if(m < b && n < b) return m * n;else if(m % b = 0 && n % b = 0) return b * fun6(m / b, n / b, b);else return fun6(m, n, + b);5 程序代码：#include <stdio.h>#include <stdlib.h>void LI(int n) int * a = malloc(n * sizeof(int);int i;for(i = 0; i < n; i +) scanf("%d", a + i);for(i = n - 1; i >= 0; i -) printf("%d ", * (a + i);printf("n");free(a);6 程序代码：int LK(double a, int n) double s = 0;int i, m = 0;for(i = 0; i < n; i +) s += ai;s /= n;for(i = 0; i < n; i +)if(ai >= s) m +;return m;参考答案：一、1、答案：运行结果：GG PP BB WW 2、答案：运行结果：12.00 160.00 3.503、答案：运行结果：main: x, y = 18, 23subs: x, y = 41, 64main: x, y = 36, 234、答案：运行结果：4321987655、运行结果：47 36 32 28 20 156、答案：运行结果：3 5 7 911 13 15 177、答案：运行结果：50 608、答案：运行结果：b=184二、1、答案：在整型数组a的前n个元素中查找值为x的元素，找到返回1，找不到返回0。2、答案：统计整型数组a的前n个元素中不小于k的元素个数并返回3、答案：程序随机产生10道20以内整数加法题，请用户回答。并统计得分， 4、答案：调用fun6(m, n, 2)求m和n的最小公倍数5、答案：读入n个整数，然后逆序输出6、答案：返回双精度数数组a的前n个元素中不小于平均值的元素个数。第四次作业一、写出下列每个程序运行后的输出结果1 程序代码：#include <stdio.h>struct Worker char name15; / 姓名int age; / 年龄float pay; / 工资void main() struct Worker x = "wanghua", 52, 2350 ;struct Worker y, * p;y = x; p = &x;printf("%s %d %6.2fn", y.name, y.age, y.pay);printf("%s %d %6.2fn", p->name, p->age + 1, p->pay + 20);2 程序代码：#include <stdio.h>#include <string.h>struct Worker char name15; / 姓名int age; / 年龄float pay; / 工资void main() struct Worker x;char * t = "liouting"int d = 38; float f = 493;strcpy(x.name, t);x.age = d; x.pay = f;x.age +; x.pay *= 2;printf("%s %d %6.2fn", x.name, x.age, x.pay);3 程序代码：#include <stdio.h>struct Worker char name15; / 姓名int age; / 年龄float pay; / 工资int Less(struct Worker r1, struct Worker r2) if(r1.age < r2.age) return 1;else return 0;void main() struct Worker a4 = "abc", 25, 420 , "def", 58, 638 , "ghi", 49, 560 , "jkl", 36, 375 ;struct Worker x = a0;int i;for(i = 1; i < 4; i +)if(Less(x, ai) x = ai;printf("%s %d %6.2fn", x.name, x.age, x.pay);二、写出下列每个函数的功能1 程序代码：struct Worker char name15; / 姓名int age; / 年龄float pay; / 工资void QA(struct Worker a, int n) int i;for(i = 1; i < n; i +)scanf("%s %d %f", &ai.name, &ai.age, &ai.pay);2 程序代码：struct StrNode char name15; / 字符串域struct StrNode * next; / 指针域struct StrNode * QB(int n) struct StrNode * f, * p;if(n = 0) return NULL;f = malloc(sizeof(struct StrNode);scanf("%s", f->name);p = f;while(- n) p = p->next = malloc(sizeof(struct StrNode);scanf("%s", p->name);p->next = NULL;return f;3 程序代码：struct IntNode int data; / 结点值域struct IntNode * next; / 结点指针域struct IntNode * FindMax(struct IntNode * f)struct IntNode * p = f;if(! f) return NULL;f = f->next;while(f) if(f->data < p->data) p = f;f = f->next;return p;4 * 程序代码：struct IntNode int data; / 结点值域struct IntNode * next; / 结点指针域int Count(struct IntNode * f)int c = 0;while(f) c +;f = f->next;return c;5 程序代码：struct IntNode int data; / 结点值域struct IntNode * next; / 结点指针域struct IntNode * Input(int n)struct IntNode * f, * p;f = malloc(sizeof(struct IntNode);if(n = 0) return NULL;f->next = NULL;printf("从键盘输入%d个整数：", n);while(n -) scanf("%d", &(f->data);p = f;f = malloc(sizeof(struct IntNode);f->next = p;return f->next;6 程序代码：#include <stdio.h>#include <stdlib.h>#include <string.h>void JA(char * fname)FILE * fout = fopen(fname, "w");char a20;printf("输入若干个字符串，每个字符串长度小于20，字符串end作为结束标志n");while(1) scanf("%s", a);if(strcmp(a, "end") = 0) break;fputs(a, fout);fputc('n', fout);fclose(fout);void main()char * p = "d:xxkxuxk1.txt"JA(p);参考答案：一、1、答案：运行结果：wanghua 52 2350.00wanghua 53 2370.002、答案：运行结果：liouting 39 986.003、答案：运行结果：def 58 638.00二、1、答案：从标准输入设备读入n-1个人员的信息，依次存到结构数组的a1到an-1元素中2、答案：创建具有n个struct StrNode结点的单向链表并返回其表头结点地址，n为0时返回NULL。3、答案：函数功能：查找单向链表中结点值域最大的结点，并返回其地址。如链表为空则返回NULL4、答案：函数功能：统计并返回单向链表结点个数5、答案：函数功能：从表尾结点开始，逆序创建具有n个struct IntNode结点的单向链表并返回其表头结点地址，n为0时返回NULL6、答案：函数功能：将输入的若干个字符串保存到文本文件d:xxkxuxk1.txt中，每个字符串一行。输入的单个字符串长度必须小于20，输入字符串end结束