80544

Run ID	Author	Problem	Lang	Verdict	Time	Memory	Code Length	Submit Time
80544	sh25_zhuwy	[在线测评解答教程] 求和	C++	Accepted	1 MS	248 KB	143	2026-01-04 15:21:30

#include<bits/stdc++.h> using namespace std; int main(){ int n; while(cin>>n){ cout<<n*(n+1)/2<<endl; } return 0; }