title: Triangular Numbers
signature: function triangular_numbers(num)
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;
  }
question_info.entry_fn_name: triangular_numbers
question_info.entry_cls_name: Solution
question_info.test_case_ids: ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
question_info.test_code: 
  
  -- SOLUTION CODE
  -- ============================================
  PLACEHOLDER_CODE_BODY
  
  -- TESTING CODE 
  -- ============================================
  function isCorrect(actual, expected)
      if type(expected) ~= type(actual) then
          return false
      end
      
      if type(expected) == 'table' then
          for k,v_expected in pairs(expected) do
              
              if actual[k] == nil then
                  return false
              end
              local v_actual = actual[k]
              if not isCorrect(v_actual, v_expected) then
                  return false
              end
              actual[k]=nil
          end
      
          if next(actual) then 
              return false
          end
          return true
      else
          return actual == expected
      end
  end
  
  function validateSolution(actual, expected)
      return isCorrect(actual,expected)
  end
  
  function driver(num, expected)
      local exec_result;
      local status, error_msg = pcall(function () 
          exec_result=PLACEHOLDER_FN_NAME(num) 
      end)
      if status then
          if validateSolution(exec_result,expected) then
              return "PASSED"
          end
          return "FAILED"
      else
          return string.format("ERROR=%s",string.gsub(error_msg,".*:[%d]+: ",""))
      end
  end
      
  function main()
      result = driver(97, false)
      print(string.format("TEST-0...%s",result))
  
      result = driver(97, false)
      print(string.format("TEST-1...%s",result))
  
      result = driver(32, false)
      print(string.format("TEST-2...%s",result))
  
      result = driver(40, false)
      print(string.format("TEST-3...%s",result))
  
      result = driver(18, false)
      print(string.format("TEST-4...%s",result))
  
      result = driver(14, false)
      print(string.format("TEST-5...%s",result))
  
      result = driver(90, false)
      print(string.format("TEST-6...%s",result))
  
      result = driver(39, false)
      print(string.format("TEST-7...%s",result))
  
      result = driver(1, true)
      print(string.format("TEST-8...%s",result))
  
      result = driver(57, false)
      print(string.format("TEST-9...%s",result))
  
  end
  
  main()
question_info.test_list: [{"idx": 0, "outputs": false, "inputs": {"num": 97}}, {"idx": 1, "outputs": false, "inputs": {"num": 97}}, {"idx": 2, "outputs": false, "inputs": {"num": 32}}, {"idx": 3, "outputs": false, "inputs": {"num": 40}}, {"idx": 4, "outputs": false, "inputs": {"num": 18}}, {"idx": 5, "outputs": false, "inputs": {"num": 14}}, {"idx": 6, "outputs": false, "inputs": {"num": 90}}, {"idx": 7, "outputs": false, "inputs": {"num": 39}}, {"idx": 8, "outputs": true, "inputs": {"num": 1}}, {"idx": 9, "outputs": false, "inputs": {"num": 57}}]