阶乘（递归实现）

#include <stdio.h>int factorial(int f){    if (f != 1)        f *= factorial(f - 1);    return f;}int main(){    printf("Input a number, I will compute the factorial for you!\n");    int f;    scanf("%d", &f);    printf("The factorial is: %d\n", factorial(f));    return 0;}