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

代码：

class Solution {    public boolean judgeCircle(String moves) {        int x=0;        int y=0;        for(int i=0;i