实验一习题2（改正错误）：#include <stdio.h>void main 改为void main(){float r, area;scanf(“%d”, &r); aea = 3.14159*r*r 改为scanf(“%f”, &r), area = 3.14159*r*r;printf(“area = %f”, area);}实验二:area = %f\n",!\n");}习题3：#include <stdio.h>加入#include “math.h”void main(){ int x, y; 改为：int x; float y;scanf(“%d”, &x);if(x>0) y = exp(-x);添加elseif(x<0) y = -exp(x);else y = 1;prinft(“y = %f\n”, y); 改为printf(”y=%f\n”, y);添加}Fly with me!实验三：习题1（九九乘法表）：#include "stdio.h"void main(){int i, j;for (i = 1; i <= 9; i++){for (j = 1; j <= 9; j++){if (i > j){printf(" ");}else{printf("%-3d", i * j);}}printf("\n");}}习题2（求1—1000的完数）：#include "stdio.h"void main(){int i,j;for (i=1;i<=1000;i++){int sum = 1;for (j=2;j<=i/2;j++){if (i%j == 0){sum+=j;}}if (sum == i){printf("%d its factor is: 1,",i);for (j=2;j<=i/2;j++){if (i%j == 0){printf("%d,",j);}}printf("\n");}}}习题3(输出结果)：#include "stdio.h"void main(){ int i, j;float s;for (i = 7; i > 4; i--){s = 0.0;for (j = i; j > 3; j--)s = s + i * j;}printf("s = %f\n", s);}Fly with me!实验四习题1(排序改进)：（1）冒泡改进：#include "stdio.h"#define N 6void main(){int a[N];int i,j,t;int flag;for (i=0;i<N;i++){scanf("%d",&a[i]);}for (i=0;i<N-1;i++){flag = 0;for(j=0;j<N-1-i;j++){if (a[j] >a[j+1]){flag = 1;t = a[j];a[j] =a[j+1];a[j+1] =t;}}if (flag == 0){break;}}for (i=0;i<N;i++){printf("%3d",a[i]);}}(2)选择改进：#include "stdio.h"#define N 6void main(){int a[N],k;int i,j,t;int flag;for (i=0;i<N;i++){scanf("%d",&a[i]);} for (i=0;i<N-1;i++){for (j=i+1;j<N;j++){k = i;if (a[k] > a[j]){k = j;}if (k!=i){t=a[i];a[i] =a[k];a[k] = t;}}}for (i=0;i<N;i++){printf("%3d",a[i]);}}习题3（改正错误）：#include "stdio.h"void main(){int i, max, min, temp, a[10];for (i=0;i<10;i++) scanf("%d", &a[i]);max = min = 0;for (i=1;i<10;i++){if (a[i]>a[max])max = i;if (a[i]<a[min])min = i;}temp = a[0];a[0] = a[min];a[min] = temp;if (max == 0){max = min;}temp = a[9];a[9] = a[max];a[max] = temp;for (i=0;i<10;i++)printf("%-3d", a[i]);}Fly with me!习题1（x的n次幂）：#include "stdio.h"double fun1(int x, int n){int i;double sum = x;for (i = 1; i < n; i++){sum = sum * x;}return sum;}void main(){int a, n;double sum;scanf("%d%d", &a,&n);sum = fun1(a, n);printf("sum = %.0f\n",sum);}习题2（两个数的所有公约数）：#include "stdio.h"void fun1(int x, int y){int i, temp;temp = x < y ? x : y;printf("%d和%d的所有公约数为：", x, y);for (i = 1; i < temp; i++){if (x % i == 0 &&y % i == 0){printf("%d ",i);}}printf("\n");}void main(){int a, b;scanf("%d%d", &a,&b);fun1(a, b);}习题3（输出结果）:#include "stdio.h"int z;int fun1(int x){if (x > 0){return 1;}else if(x < 0){return -1;}else{return 0;}}int fun2(int x){z = z - x;return fun1(x);}void main(){int a1, a2;z = 10;a1 = fun2(10) * fun2(z);printf("%d, %d\n", a1,z);z = 10;a2 = fun2(z) * fun2(10);printf("%d, %d\n", a2,z);}Fly with me!习题1（插入一个数）：#include "stdio.h"void insert(int a[], int n, int x){int pos, i;// 初值为最后一个元素pos = n;// 确定要插入的数字的位置for (i = 0; i < n; i++){if (a[i] > x){pos = i;break;}}// 后移数组元素for (i = n; i > pos; i--){a[i] = a[i - 1];}// 插入数字xa[pos] = x;}void main(){int i, m;int a[10] = {3, 7, 9, 12,15};scanf("%d", &m);insert(a, 5, m);for (i = 0; i < 6; i++){printf("%d ", a[i]);}putchar('\n');}习题3（改正错误）：#include "stdio.h"#include "string.h"int fun(int score[], int m, int below[]) {int i, k=0;float aver;改为float aver = 0.0;for (i=0;i<m;i++){aver = aver + score[i];aver = aver / m; aver = aver / m;}添加：aver = aver / m;for (i=0;i<m;i++){if (score[i] < aver){below[k] = score[i];k++;return k;}}添加：return k;}void main(){int i, n, below[9];int score[9] = {10, 20, 30, 40, 50, 60, 70, 80, 90};n = fun(score, 9, below[9]) ;改为：n = fun(score, 9, below) ;printf("Below the average score are:");for (i=0;i<n;i++){printf("%d ", below[i]);}printf("\n");}Fly with me!习题1（输出数组中最大及最小元素）：#include "stdio.h"void fun(int *s, int *max, int *min){int *p = s;*max = *min = *p;for (;p < s + 6; p++){if (*max < *p){*max = *p;}if (*min > *p){*min = *p;}}}void main(){int a[6];int i, max, min;for (i = 0; i < 6;i++){scanf("%d", &a[i]);}fun(a, &max, &min);printf("max = %d, min = %d\n", max, min); }习题2（数组交换）:#include "stdio.h"void swap(int *a, int *b){int temp;temp = *a;*a = *b;*b = temp;}void main(){int a[5] = {1, 3, 5, 7, 9};int b[5] = {2, 4, 6, 8, 10};int i; printf("数组a为：");for (i = 0; i < 5;i++){printf("%d ", a[i]);}printf("\n");printf("数组b为：");for (i = 0; i < 5;i++){printf("%d ", b[i]);}printf("\n");for (i = 0; i < 5;i++){swap(&a[i], &b[i]);}printf("交换后：\n");printf("数组a为：");for (i = 0; i < 5;i++){printf("%d ", a[i]);}printf("\n");printf("数组b为：");for (i = 0; i < 5;i++){printf("%d ", b[i]);}printf("\n");}习题3（改正错误）：#include "stdio.h"改为：void fun(char *s, int *a, int *b) {while (*s){ 改为：if (*s >= 'A' && *s <= 'Z') (*a)++;改为：if (*s >= 'a' && *s <= 'z') (*b)++;s++;} }void main(){int upper = 0, lower = 0;char s[100];gets(s);fun(s, &upper, &lower);printf("\n upper = %d, lower = %d\n", upper, lower);}Fly with me!习题1：#include "stdio.h" #define N 10 struct Student { int num;char name[10];float chinese;float math;float english;};void main(){ int i;struct Student students[N];struct Student chi_stu, math_stu, eng_stu;for (i=0;i<N;i++){ scanf("%d%s%f%f%f",&students[i].num, students[i].name, &students[i].chinese , &students[i].math, &students[i].english);}chi_stu = students[0];math_stu = students[0];eng_stu = students[0];for (i=1;i<N;i++){if (students[i].chinese > chi_stu.chinese){chi_stu = students[i];}if (students[i].math > math_stu.math){math_stu = students[i];}if (students[i].english > eng_stu.english){eng_stu = students[i];}}printf("语文最好的学生信息为：\n");printf("%d %s %4.1f %4.1f %4.1f\n", chi_stu.num, chi_, chi_stu.chinese , chi_stu.math, chi_stu.english);printf("数学最好的学生信息为：\n");printf("%d %s %4.1f %4.1f %4.1f\n", math_stu.num, math_, math_stu.chinese , math_stu.math, math_stu.english);printf("英语最好的学生信息为：\n");printf("%d %s %4.1f %4.1f %4.1f\n", eng_stu.num, eng_, eng_stu.chinese , eng_stu.math, eng_stu.english); }Fly with me!习题2：#include "stdio.h"#define N 5struct Student{int num;char name[10];float english;};float average(struct Student stu[]){int i;float sum = 0;for (i=0;i<N;i++){sum += stu[i].english;}sum = sum / N;return sum;}// 选择排序void sort1(struct Student stu[]){int i, j, k;struct Student temp;for (i=0;i<N-1;i++){for (j=i+1;j<N;j++){k = i;if (stu[k].english < stu[j].english){k = j;}if (k != i){temp = stu[i];stu[i] = stu[j];stu[j] = temp;}}}Fly with me!}// 冒泡排序void sort2(struct Student stu[]){int i, j;int flag;struct Student temp;for (i=0;i<N-1;i++){flag = 0;for (j=0;j<N-i-1;j++){if (stu[j].english < stu[j+1].english){flag = 1;temp = stu[j];stu[j] = stu[j+1];stu[j+1] = temp;}}if (flag == 0) break;}}void main(){int i;struct Student students[N];for (i=0;i<N;i++){scanf("%d%s%f", &students[i].num, students[i].name, &students[i].english);}printf("平均值为：%4.1f\n", average(students));sort2(students);printf("成绩清单（从高到低）:\n");for (i=0;i<N;i++){printf("%5d%10s%7.1f\n", students[i].num, students[i].name, students[i].english);}}Fly with me!。
