message: Refactor 'Distribute candies' solution
diff: # The length of the given array is in range [2, 10,000], and will be even.
  # The number in given array is in range [-100,000, 100,000].
  +
  class Solution(object):
  +
  def distributeCandies(self, candies):
  """
  :type candies: List[int]
  :rtype: int
  """
  - lookup = set()
  - for candy in candies:
  - lookup.add(candy)
  + lookup = set(candies)
  return min(len(lookup), len(candies)/2)
  