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.
判断字符串能否回到原点（R_L, U_D）。
Example 1:
Input: "UD"
Output: true
Example 2:
Input: "LL"
Output: false
class Solution:
def judgeCircle(self, moves):
"""
:type moves: str
:rtype: bool
"""
if moves.count('U') == moves.count('D') and moves.count('L') == moves.count('R'):
return True
else:
return False
