code: def get_longest_non_repeat_v2(string):
      """
      Find the length of the longest substring
      without repeating characters.
      Uses alternative algorithm.
      Return max_len and the substring as a tuple
      """
      if string is None:
          return 0, ""
      sub_string = ""
      start, max_len = 0, 0
      used_char = {}
      for index, char in enumerate(string):
          if char in used_char and start <= used_char[char]:
              start = used_char[char] + 1
          else:
              if index - start + 1 > max_len:
                  max_len = index - start + 1
                  sub_string = string[start : index + 1]
          used_char[char] = index
      return max_len, sub_string
  
label_desc: Use image node_id 4 for calling a global function with example usage: get_longest_non_repeat_v2(string) and returns: max_len,  sub_string, int,  str