题解 | #n的阶乘#

#include<cstdio>
long long fun(int n){
    if(n == 1){
        return 1;
    }else {
    return n * fun(n-1);
    }
}
int main(){
    int n;
    while(scanf("%d",&n) != EOF){
        printf("%lld\n",fun(n));
    }
}