title: Count Natural Numbers Whose Permutation Greater Number
signature: function count_natural_numbers_whose_permutation_greater_number(n)
source_py: def count_natural_numbers_whose_permutation_greater_number(n):
      result = 0
      for i in range(1, 10):
          s = []
          if (i <= n):
              s.append(i)
              result += 1
          while (len(s) != 0):
              tp = s[(- 1)]
              s.pop()
              for j in range((tp % 10), 10):
                  x = ((tp * 10) + j)
                  if (x <= n):
                      s.append(x)
                      result += 1
      return result
source_cpp: int count_natural_numbers_whose_permutation_greater_number(int n) {
    int result = 0;
    for ( int i = 1;
    i <= 9;
    i ++ ) {
      stack < int > s;
      if ( i <= n ) {
        s . push ( i );
        result ++;
      }
      while ( ! s . empty ( ) ) {
        int tp = s . top ( );
        s . pop ( );
        for ( int j = tp % 10;
        j <= 9;
        j ++ ) {
          int x = tp * 10 + j;
          if ( x <= n ) {
            s . push ( x );
            result ++;
          }
        }
      }
    }
    return result;
  }
question_info.entry_fn_name: count_natural_numbers_whose_permutation_greater_number
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(n, expected)
      local exec_result;
      local status, error_msg = pcall(function () 
          exec_result=PLACEHOLDER_FN_NAME(n) 
      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(69, 48)
      print(string.format("TEST-0...%s",result))
  
      result = driver(72, 48)
      print(string.format("TEST-1...%s",result))
  
      result = driver(88, 52)
      print(string.format("TEST-2...%s",result))
  
      result = driver(7, 7)
      print(string.format("TEST-3...%s",result))
  
      result = driver(66, 45)
      print(string.format("TEST-4...%s",result))
  
      result = driver(34, 28)
      print(string.format("TEST-5...%s",result))
  
      result = driver(23, 20)
      print(string.format("TEST-6...%s",result))
  
      result = driver(37, 31)
      print(string.format("TEST-7...%s",result))
  
      result = driver(33, 27)
      print(string.format("TEST-8...%s",result))
  
      result = driver(21, 18)
      print(string.format("TEST-9...%s",result))
  
  end
  
  main()
question_info.test_list: [{"idx": 0, "outputs": 48, "inputs": {"n": 69}}, {"idx": 1, "outputs": 48, "inputs": {"n": 72}}, {"idx": 2, "outputs": 52, "inputs": {"n": 88}}, {"idx": 3, "outputs": 7, "inputs": {"n": 7}}, {"idx": 4, "outputs": 45, "inputs": {"n": 66}}, {"idx": 5, "outputs": 28, "inputs": {"n": 34}}, {"idx": 6, "outputs": 20, "inputs": {"n": 23}}, {"idx": 7, "outputs": 31, "inputs": {"n": 37}}, {"idx": 8, "outputs": 27, "inputs": {"n": 33}}, {"idx": 9, "outputs": 18, "inputs": {"n": 21}}]