Counting ones

input/code.cpp: In function 'int main()':
input/code.cpp:14:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |   scanf("%zu", &n);
      |   ~~~~~^~~~~~~~~~~
input/code.cpp:17:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     scanf("%lu", &data[i]);
      |     ~~~~~^~~~~~~~~~~~~~~~~

#include<cstdio>
#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
#pragma GCC optimize "Ofast"
#pragma GCC optimize "unroll-loops"

long int data[200000];

int main() {
  #ifdef ONPC
  freopen("A2.in", "r", stdin);
  #endif

  size_t n;
  scanf("%zu", &n);

  for (size_t i = 0; i < n; i++) {
    scanf("%lu", &data[i]);
  }

  int ans = 0;
  size_t imax = -1;
  size_t jmax = -1;
  for (size_t i = 0; i < n; i++) {
    for (size_t j = i; j < n; j++) {
      int count = __builtin_popcountll(data[i] * data[j]);
      if(count > ans) {
        imax = i;
        jmax = j;
        ans = count;
      }
    }
  }

  printf("%d\n%zu %zu\n", ans, data[imax], data[jmax]);
  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