44119

Run ID	Author	Problem	Lang	Verdict	Time	Memory	Code Length	Submit Time
44119	chenyanda	求1+2+3+...	C++	Accepted	1 MS	248 KB	96	2024-03-29 14:54:32

#include<iostream> using namespace std; int main() { int n; cin>>n; cout<<n*(n+1)/2; }