1、

#include <stdio.h>

int main(void)
{
    int i, j, x, y, z;
    do
    {
        puts("please input an integer.");
        printf("x = "); scanf("%d", &x);
    }
    while (x < 0 || x > 100);
    
    putchar('\n');
    y = x; z = x;
    while ( y >= 0)
    {
        printf("y:%d  z:%d\n", y--, z++);
    }
    
    printf("\nsquare is %d.\n", x);
    printf("the propable sides i are :\n");
    for (i = 1; i <= x; i ++)
    {
        if (i * i > x)
            break;
        if (x % i != 0)
            continue;
        printf("side1:%d  side2:%d\n", i, x / i);
    }
    
    printf("\ndraw a star tangle!\n");
    for (i = 1; i <= 3; i ++)
    {
        for (j  = 1; j <= 5; j++)
        {
            putchar('*');
        }
        putchar('\n');
    }
    return 0;
    
}

c语言中循环语句汇总_C语言