Neliöt

input/code.cpp: In function 'int main()':
input/code.cpp:18:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       if (j < sq.size() && sq[j] == x) f=1;
           ~~^~~~~~~~~~~

#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int T;
  cin >> T;
  vector<int> sq;
  for (int i = 0; i*i <= int(1e9); ++i) sq.push_back(i*i);
  for (int Ti = 0; Ti < T; ++Ti) {
    int n;
    cin >> n;
    bool f=0;
    for (int a : sq) {
      if (a > n) break;
      int x = n-a;
      int j = lower_bound(sq.begin(), sq.end(), x)-sq.begin();
      if (j < sq.size() && sq[j] == x) f=1;
    }
    if (f) cout << "YES\n";
    else cout << "NO\n";
  }
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 2

Verdict: ACCEPTED