C语言_简单的阶乘函数

include 
long jc (int num);
long jc2 (int num);
int main()
{
    long n;
    n = jc(5);
    printf("%d", n);
//    n = jc2(5);
//    printf("%d", n);
}

/**
* for循环 
*/
long jc (int num)
{
    long j = 1, i;    
    for (i = 1; i <= num; i++){
        j *= i;              //一直乘以步长+1的数，直到自增到参数 
    }
    return j;
}
/**递归 
* 5! = 1 * 2 * 3 * 4 * 5;
* 4! = 1 * 2 * 3 * 4;
* 3! = 1 * 2 * 3;
* 2! = 1 * 2;
* 1! = 1;
**/
long jc2 (int num)
{
    long j;
    //printf("%d", num);
    if (num > 1) {
        //printf("%d", num);
        j = jc2(num - 1) * num;    //如果要求5的阶乘，那么先求出比5小1的阶乘以5。 
    } else {
        //printf("%d", num);
        j = 1;
    }
    return j;
}

 

转载于:https://www.cnblogs.com/wt645631686/p/8177326.html