new_contents: # Time:  O(n)
  # Space: O(1)
  
  # Initially, there is a Robot at position (0, 0). Given a sequence of its moves,
  # judge if this robot makes a circle, which means it moves back to the original place.
  #
  # The move sequence is represented by a string. And each move is represent by a character.
  # The valid robot moves are R (Right), L (Left), U (Up) and D (down).
  # The output should be true or false representing whether the robot makes a circle.
  #
  # Example 1:
  # Input: "UD"
  # Output: true
  # Example 2:
  # Input: "LL"
  # Output: false
      
  class Solution(object):
      def judgeCircle(self, moves):
          """
          :type moves: str
          :rtype: bool
          """
          v, h = 0, 0
          for move in moves:
              if move == 'U':
                  v += 1
              elif move == 'D':
                  v -= 1
              elif move == 'R':
                  h += 1
              elif move == 'L':
                  h -= 1
          return v == 0 and h == 0
  
subject: Create judge-route-circle.py