44178

Run ID	Author	Problem	Lang	Verdict	Time	Memory	Code Length	Submit Time
44178	chenyifei	求1+2+3+...	C++	Accepted	0 MS	240 KB	108	2024-03-29 15:14:00

#include<iostream> using namespace std; int main() { int n; cin>>n; cout<<n*(n+1)/2; return 0; }