题解 | #n的阶乘#

#include <cstdio>
#include <iostream>

using namespace std;

long long fact(int n){
    if(n==0){
        return 1;
    }else{
        return n*fact(n-1);
    }
}
int main(){
    int n;
    while(scanf("%d",&n)!=EOF){
        printf("%lld\n",fact(n));
    }
    return 0;
}