LeetCode 答案(Easy)（601-700）

657-Judge Route Circle （判断 圈形路线）

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.
一开始，机器人位于(0,0)。输入一串移动次序命令，判断机器人是否走了一个圈，也就是说它是否回到了原点。

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.
移动顺序是一串字符串。每一步移动命令都是一个字符。有效的移动命令包括 R（向右） ，L（向左），U（向上）以及D（向下）。最终的输出是true或者false,同来表示机器人是否走了一个圈。

Example 1:Input: "UD"Output: true

Example 2:Input: "LL"Output: false

• 答案

public class Solution {    public boolean judgeCircle(String moves) {        // x轴坐标        int x = 0;        // y轴坐标        int y = 0;        for (int j = 0, length = moves.length(); j < length; j++) {            if (moves.charAt(j) == 'R') {               x++;            }            if (moves.charAt(j) == 'L') {                 x--;            }            if (moves.charAt(j) == 'U') {                 y++;            }            if (moves.charAt(j) == 'D') {                 y--;            }        }       // System.out.println("机器人当前的坐标是：("+x+","+y+")");        return (x==0&&y==0);    }}