正确方法：
#include<bits/stdc++.h> using namespace std; int main() { long long a; cin>>a; for(int i=a-1;i>0;i--)a*=i; cout<<a; }
By signing up a Hydro universal account, you can submit code and join discussions in all online judging services provided by us.
Using your Hydro universal account
ALT_zengzechuan
LV 7
@ 2025-12-20 8:31:58
