message: Update robot-return-to-origin.py
diff: # Time: O(n)
  # Space: O(1)
  +import collections
  +
  +
  +class Solution(object):
  + def judgeCircle(self, moves):
  + """
  + :type moves: str
  + :rtype: bool
  + """
  + count = collections.Counter(moves)
  + return count['L'] == count['R'] and count['U'] == count['D']
  +
  +
  +# Time: O(n)
  +# Space: O(1)
  class Solution(object):
  def judgeCircle(self, moves):
  """
  @@ -18,4 +33,3 @@ class Solution(object):
  elif move == 'L':
  h -= 1
  return v == 0 and h == 0
  -
  