Counting ones

input/code.cpp: In function 'int main()':
input/code.cpp:6:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    6 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
input/code.cpp:9:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |         scanf("%lld", &a[i]);
      |         ~~~~~^~~~~~~~~~~~~~~

#include <bits/stdc++.h>
using namespace std;

int main() {
    int n;
    scanf("%d", &n);
    vector<long long> a(n);
    for (int i = 0; i < n; i++) {
        scanf("%lld", &a[i]);
}

    int best = -1;
    long long x = 0;
    long long y = 0;
    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            
            int c = __builtin_popcountll(a[i] * a[j]);
            
            if (c > best) {
                best = c;
                x = a[i];
                y = a[j];
            }
        }
    }
    printf("%d\n%lld %lld\n", best, x, y);
}

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