message: Update jewels-and-stones.py
diff: # Time: O(m + n)
  # Space: O(n)
  +# You're given strings J representing the types of stones that are jewels,
  +# and S representing the stones you have.
  +# Each character in S is a type of stone you have.
  +# You want to know how many of the stones you have are also jewels.
  +#
  +# The letters in J are guaranteed distinct, and all characters in J and S are letters.
  +# Letters are case sensitive, so "a" is considered a different type of stone from "A".
  +#
  +# Example 1:
  +# Input: J = "aA", S = "aAAbbbb"
  +# Output: 3
  +# Example 2:
  +#
  +# Input: J = "z", S = "ZZ"
  +# Output: 0
  +#
  +# Note:
  +# - S and J will consist of letters and have length at most 50.
  +# - The characters in J are distinct.
  +
  class Solution(object):
  def numJewelsInStones(self, J, S):
  """
  