BOJ 21185 - Some Sum [C++]

문제

링크

풀이

#include <iostream>
using namespace std;
 
void solve(void) {
  int n; cin >> n;
 
  cout << (n & 1 ? "Either" : ((n*(n+1)/2) & 1 ? "Odd" : "Even"));
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  solve();
  return 0;
}