算法--leetcode 657. Judge Route Circle

题目：

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.

题意：

有一个机器人从原点（0，0）的位置出发，输入一段字串（U，D，L，R），代表向上、下、左、右的移动顺序，求执行完顺序后是否能回到原点

Python 解：

思路：运用 .count(' ')函数，判断L和R，D和U的数量是否相等。

class Solution(object):
    def judgeCircle(self, moves):
        """
        :type moves: str
        :rtype: bool
        """
        return moves.count('R')==moves.count('L') and moves.count('U')==moves.count('D')