C语言——函数练习程序

1.从终端接收一个数,封装一个函数判断该数是否为素数

#include <stdio.h>int pri(int num)
{int i = 0;for (i = 2; i < num; i++){if (num % i ==0){return 0;break;}}if (i == num-1){return 1;}
}int main(void)
{int num = 0;int ret = 0;scanf("%d", &num);ret = pri(num);if (ret){printf("该数是素数！\n");}else{printf("该数不是素数！\n");}return 0;
}

2.封装一个函数实现获得两个数的最大公约数

#include <stdio.h>int gcd(int num1, int num2)
{int i = 1;int j = 1;int cnt_1 = 0;int cnt_2 = 0;int n1[100] = {0};int n2[100] = {0};int tmp = 0;for (i = 1; i <= num1; i++){if (num1 % i == 0){n1[cnt_1] = i;cnt_1++;}}for (j = 1; j <= num2; j++){if (num2 % j == 0){n2[cnt_2] = j;cnt_2++;}}for (i = 0; i < cnt_1-1; i++){for (j = 0; j < cnt_1-1-i; j++){if (n1[j] > n1[j+1]){tmp = n1[j];n1[j] = n1[j+1];n1[j+1] = tmp;}}}for (i = 0; i < cnt_2-1; i++){for (j = 0; j < cnt_2-1-i; j++){if (n2[j] > n2[j+1]){tmp = n2[j];n2[j] = n2[j+1];n2[j+1] = tmp;}}}for (i = cnt_1-1; i >= 0; i--){for (j = cnt_2-1; j >= 0; j--){if (n1[i] == n2[j]){return n1[i];}}}
}int main(void)
{int num1 = 0;int num2 = 0;int ret = 0;scanf("%d%d", &num1, &num2);ret = gcd(num1, num2);printf("最大公约数为%d\n", ret);}

3.封装一个函数实现获得两个数的最小公倍数

#include <stdio.h>int lcm(int num1, int num2)
{int n1[100] = {0};int n2[100] = {0};int i = 0;int j = 0;for (i = 0; i < 100; i++){n1[i] = num1 * (i+1);}for (i = 0; i < 100; i++){n2[i] = num2 * (i+1);}for (i = 0; i < 100; i++){for (j = 0; j < 100; j++){if (n1[i] == n2[j]){return n1[i];}}}}int main(void)
{int num1 = 0;int num2 = 0;int ret = 0;scanf("%d%d", &num1, &num2);ret = lcm(num1, num2);printf("最小公倍数为：%d\n", ret);return 0;
}

4. 封装一个函数判断该年是否为闰年

#include <stdio.h>int leapyear(int year)
{if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0){return 1;}return 0;
}int main(void)
{int year = 0;int ret = 0;scanf("%d", &year);ret = leapyear(year);if (ret == 1){printf("该年是闰年！\n");}else {printf("该年是非闰年！\n");}return 0;
}