实验五4

# include "stdafx.h"
# include <stdio.h>
int f(int n)
{
    if(n==1||n==2)
        return n;
    else
        return n*f(n-1);
}

int main(int argc, char** argv)
{
    int n,sum;
    scanf("%d",&n);
    sum=f(n);
    printf("%d\n",sum);
    return 0;

}