title: Count Index Pairs Equal Elements Array
signature: function countIndexPairsEqualElementsArray($arr, $n) {
test_code: <?php
  
  
  // SOLUTION CODE 
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function validateSolution($actual, $expected){
      return serialize($actual) == serialize($expected);
  }
  
  function driver($arr, $n, $expected){
      try{
        if (validateSolution(PLACEHOLDER_FN_NAME($arr, $n), $expected)){
          return "PASSED";
        }
        return "FAILED";
      }
      catch (Exception $exception_obj) {
        return get_class($exception_obj);
      }
  }
  
  function main(){
      printf("TEST-0...%s\n",driver(
        array(4, 6, 9, 16, 16, 21, 36, 41, 58, 60, 62, 73, 77, 81, 95), 12, 
        1));
      
      printf("TEST-1...%s\n",driver(
        array(-86, -72, -26, -34, 18, -62, -66), 3, 
        0));
      
      printf("TEST-2...%s\n",driver(
        array(1), 0, 
        0));
      
      printf("TEST-3...%s\n",driver(
        array(16), 0, 
        0));
      
      printf("TEST-4...%s\n",driver(
        array(-88, -80, -72, -68, -64, -26, 4, 14, 16, 22, 30, 32, 60, 74, 82), 11, 
        0));
      
      printf("TEST-5...%s\n",driver(
        array(0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1), 9, 
        16));
      
      printf("TEST-6...%s\n",driver(
        array(3, 9, 10, 12, 17, 23, 27, 29, 42, 44, 59, 61, 71, 76, 78, 82, 84, 84, 89, 90, 93, 93, 97, 97), 15, 
        0));
      
      printf("TEST-7...%s\n",driver(
        array(68, -40, -46, -20, -64, 90), 5, 
        0));
      
      printf("TEST-8...%s\n",driver(
        array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1), 15, 
        61));
      
      printf("TEST-9...%s\n",driver(
        array(99, 17, 94, 43, 97, 17, 11, 58, 75, 94, 37, 22, 54, 31, 41, 4, 55, 69, 92, 80, 45, 97, 16, 33, 36, 17, 43, 82, 81, 64, 22, 65, 85, 44, 47, 14), 23, 
        3));
      
  }
  
  main();
  ?>
source_py: def count_index_pairs_equal_elements_array(arr, n):
      ans = 0
      for i in range(0, n):
          for j in range((i + 1), n):
              if (arr[i] == arr[j]):
                  ans += 1
      return ans
source_cpp: int count_index_pairs_equal_elements_array(vector<int> arr, int n) {
    int ans = 0;
    for ( int i = 0;
    i < n;
    i ++ ) for ( int j = i + 1;
    j < n;
    j ++ ) if ( arr [ i ] == arr [ j ] ) ans ++;
    return ans;
  }