657. 机器人能否返回原点

Java代码：

class Solution {
    public boolean judgeCircle(String moves) {
        int[] x = {0, 0, -1, 1};
        int[] y = {1, -1, 0, 0};
        String str = "UDLR";

        int xx = 0, yy = 0;
        for (int i = 0; i < moves.length(); i++) {
            xx += x[str.indexOf(moves.charAt(i))];
            yy += y[str.indexOf(moves.charAt(i))];
        }

        return xx == 0 && yy == 0;
    }
}