title: Divisibility By 7
signature: function divisibility_by_7(num)
source_py: def divisibility_by_7(num):
      if (num < 0):
          return divisibility_by_7((- num))
      if ((num == 0) or (num == 7)):
          return True
      if (num < 10):
          return False
      return divisibility_by_7(((num / 10) - (2 * (num - ((num / 10) * 10)))))
source_cpp: int divisibility_by_7(int num) {
    if ( num < 0 ) return divisibility_by_7 ( - num );
    if ( num == 0 || num == 7 ) return 1;
    if ( num < 10 ) return 0;
    return divisibility_by_7 ( num / 10 - 2 * ( num - num / 10 * 10 ) );
  }
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(0, true)
      print(string.format("TEST-0...%s",result))
  
      result = driver(-21, false)
      print(string.format("TEST-1...%s",result))
  
      result = driver(7, true)
      print(string.format("TEST-2...%s",result))
  
      result = driver(63, false)
      print(string.format("TEST-3...%s",result))
  
      result = driver(84, false)
      print(string.format("TEST-4...%s",result))
  
      result = driver(73, false)
      print(string.format("TEST-5...%s",result))
  
      result = driver(81, false)
      print(string.format("TEST-6...%s",result))
  
      result = driver(-10, false)
      print(string.format("TEST-7...%s",result))
  
      result = driver(47, false)
      print(string.format("TEST-8...%s",result))
  
      result = driver(23, false)
      print(string.format("TEST-9...%s",result))
  
  end
  
  main()
question_info.entry_cls_name: Solution
question_info.test_list: [{"idx": 0, "outputs": true, "inputs": {"num": 0}}, {"idx": 1, "outputs": false, "inputs": {"num": -21}}, {"idx": 2, "outputs": true, "inputs": {"num": 7}}, {"idx": 3, "outputs": false, "inputs": {"num": 63}}, {"idx": 4, "outputs": false, "inputs": {"num": 84}}, {"idx": 5, "outputs": false, "inputs": {"num": 73}}, {"idx": 6, "outputs": false, "inputs": {"num": 81}}, {"idx": 7, "outputs": false, "inputs": {"num": -10}}, {"idx": 8, "outputs": false, "inputs": {"num": 47}}, {"idx": 9, "outputs": false, "inputs": {"num": 23}}]
question_info.extension: lua
question_info.entry_fn_name: divisibility_by_7
question_info.test_case_ids: 0 1 2 3 4 5 6 7 8 9
question_info.commands: lua __FILENAME__