input: def calculate_string_stats(string: str) -> tuple:
      """
      Calculate the maximum, minimum, and mean number of elements in a given string.
      
      >>> calculate_string_stats("abcdef")
      ('f', 'a', 100.0)
      >>> calculate_string_stats("hello")
      ('o', 'e', 108.0)
      """
      num_elements = len(string)
      max_element = max(string)
      min_element = min(string)
      mean_element = sum(map(ord, string)) / num_elements
      return (max_element, min_element, mean_element)
output:     num_elements = len(string)
      max_element = max(string)
      min_element = min(string)
      mean_element = sum(map(ord, string)) / num_elements
      return (max_element, min_element, mean_element)