Counting ones

#include <iostream>
#include <vector>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n;
    if (!(cin >> n)) return 0;

    vector<long long> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    int max_bits = -1;
    long long ans_i = -1, ans_j = -1;

    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            long long product = a[i] * a[j];
            
            int current_bits = __builtin_popcountll(product);

            if (current_bits > max_bits) {
                max_bits = current_bits;
                ans_i = a[i];
                ans_j = a[j];
            }
        }
    }

    cout << max_bits << "\n";
    cout << ans_i << " " << ans_j << "\n";

    return 0;
}

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