n的阶乘实例 5! == 5 * 4 * 3 * 2 * 1 5! == 5 * 4! 4! == 4 * 3! n! = n * (n - 1)!

#include <stdio.h>
int jiecheng(int n)
{
    int x;
    if(n == 1)
        return 1;
    x = n * jiecheng(n - 1);
    return x;
}
int main()
{
    int x = jiecheng(5);
    printf("x is %d\n", x);
}