title: Triangular Numbers
signature: function triangularNumbers($num) {
test_code: <?php
  
  
  // SOLUTION CODE 
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function validateSolution($actual, $expected){
      return serialize($actual) == serialize($expected);
  }
  
  function driver($num, $expected){
      try{
        if (validateSolution(PLACEHOLDER_FN_NAME($num), $expected)){
          return "PASSED";
        }
        return "FAILED";
      }
      catch (Exception $exception_obj) {
        return get_class($exception_obj);
      }
  }
  
  function main(){
      printf("TEST-0...%s\n",driver(
        97, 
        false));
      
      printf("TEST-1...%s\n",driver(
        97, 
        false));
      
      printf("TEST-2...%s\n",driver(
        32, 
        false));
      
      printf("TEST-3...%s\n",driver(
        40, 
        false));
      
      printf("TEST-4...%s\n",driver(
        18, 
        false));
      
      printf("TEST-5...%s\n",driver(
        14, 
        false));
      
      printf("TEST-6...%s\n",driver(
        90, 
        false));
      
      printf("TEST-7...%s\n",driver(
        39, 
        false));
      
      printf("TEST-8...%s\n",driver(
        1, 
        true));
      
      printf("TEST-9...%s\n",driver(
        57, 
        false));
      
  }
  
  main();
  ?>
source_py: def triangular_numbers(num):
      if (num < 0):
          return False
      (sum, n) = (0, 1)
      while (sum <= num):
          sum = (sum + n)
          if (sum == num):
              return True
          n += 1
      return False
source_cpp: bool triangular_numbers(int num) {
    if ( num < 0 ) return false;
    int sum = 0;
    for ( int n = 1;
    sum <= num;
    n ++ ) {
      sum = sum + n;
      if ( sum == num ) return true;
    }
    return false;
  }