[leetcode]657. Judge Route Circle

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 {    public boolean judgeCircle(String moves) {        int x = 0;        int y = 0;        for (int i = 0; i < moves.length(); i++) {            char c = moves.charAt(i);            switch (c) {                case 'U':                    y++;                    break;                case 'D':                    y--;                    break;                case 'R':                    x++;                    break;                case 'L':                    x--;                    break;                default:                    break;            }        }        return x == 0 && y == 0;    }}