Counting ones

input/code.cpp: In function 'int main()':
input/code.cpp:15:19: warning: comparison of integer expressions of different signedness: 'int' and 'ull' {aka 'long long unsigned int'} [-Wsign-compare]
   15 |     for(int i=0; i<n; i++){
      |                  ~^~
input/code.cpp:23:19: warning: comparison of integer expressions of different signedness: 'int' and 'ull' {aka 'long long unsigned int'} [-Wsign-compare]
   23 |     for(int j=0; j<n; j++){
      |                  ~^~
input/code.cpp:24:23: warning: comparison of integer expressions of different signedness: 'int' and 'ull' {aka 'long long unsigned int'} [-Wsign-compare]
   24 |         for(int i=0; i<n; i++){
      |                      ~^~

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    ull n;
    cin >> n;

    vector<ull> as;
    as.reserve(n);
    for(int i=0; i<n; i++){
        ull a; cin >> a;
        as.push_back(a);
    }

    ll maxz = -1;
    ull ma = -1, mb = -1;

    for(int j=0; j<n; j++){
        for(int i=0; i<n; i++){
            if(i == j) continue;
            ll ones = __builtin_popcountll(as[i] * as[j]);
            if(ones > maxz){
                maxz = ones;
                ma = i;
                mb = j;
            }
        }
    }

    if(ma > mb) swap(ma, mb);
    cout << maxz << "\n" << as[ma] << " " << as[mb] << "\n";
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED