44100

Run ID	Author	Problem	Lang	Verdict	Time	Memory	Code Length	Submit Time
44100	lnx	求1+2+3+...	C++	Accepted	1 MS	244 KB	109	2024-03-29 14:50:09

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