Counting ones

In file included from /usr/include/c++/13/bits/unique_ptr.h:42,
                 from /usr/include/c++/13/memory:78,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:56,
                 from input/code.cpp:1:
In member function 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>]',
    inlined from 'int main()' at input/code.cpp:33:32:
/usr/include/c++/13/ostream:204:25: warning: 'a' may be used uninitialized [-Wmaybe-uninitialized]
  204 |       { return _M_insert(__n); }
      |                ~~~~~~~~~^~~~~
input/code.cpp: In function 'int main()':
input/code.cpp:19:8: note: 'a' was declared here
   19 |     ll a, b;
      |        ^
In member function 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>]',
    inlined from '...

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

int main() {
    const int MAXN = 1e4;
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    int n;
    cin >> n;

    ll nums[MAXN];

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

    ll a, b;
    int maxBits = 0;

    for (int i=0; i<n-1; i++) {
        for (int j=i+1; j<n; j++) {
            int bits = __builtin_popcountll(nums[i] * nums[j]);
            if (bits > maxBits) {
                maxBits = bits;
                a = nums[i];
                b = nums[j];
            }
        }
    }

    cout << maxBits << "\n" << a << " " << b << "\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