message: Update next-closest-time.py
diff: # Time: O(1)
  # Space: O(1)
  +# Given a time represented in the format "HH:MM",
  +# form the next closest time by reusing the current digits.
  +# There is no limit on how many times a digit can be reused.
  +#
  +# You may assume the given input string is always valid.
  +# For example, "01:34", "12:09" are all valid. "1:34", "12:9" are all invalid.
  +#
  +# Example 1:
  +#
  +# Input: "19:34"
  +# Output: "19:39"
  +# Explanation: The next closest time choosing from digits 1, 9, 3, 4, is 19:39, which occurs 5 minutes later.
  +# It is not 19:33, because this occurs 23 hours and 59 minutes later.
  +#
  +# Example 2:
  +#
  +# Input: "23:59"
  +# Output: "22:22"
  +# Explanation: The next closest time choosing from digits 2, 3, 5, 9, is 22:22.
  +# It may be assumed that the returned time is next day's time since it is smaller than the input time numerically.
  +
  class Solution(object):
  def nextClosestTime(self, time):
  """
  