Counting ones

#include <bits/stdc++.h>

using namespace std;

#define debug(x) cerr << #x << ": " << x << endl;
#define ll long long
#define ull unsigned long long
#define vi vector<int>

int main() {
    int n;
    cin >> n;

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

    int maxi = -1;
    int v;
    ll l = 0, r = 0;
    for (int i = 0; i < n-1; i++)
    {
        for (int j = i+1; j < n; j++)
        {
            v = __builtin_popcountll(a[i]*a[j]);
            if (v > maxi) {
                maxi = v;
                l = a[i]; r = a[j];
            }
        }   
    }
    
    cout << maxi << endl;
    cout << l << ' ' << r << endl;    

    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