657. Judge Route Circle

最新推荐文章于 2021-02-14 19:40:03 发布

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本文介绍了一个简单的方法来判断一个机器人在二维平面上移动后是否回到了初始位置(0,0)。通过解析输入字符串，该字符串由字符'R'(右)、'L'(左)、'U'(上)和'D'(下)组成，代表机器人的移动指令。根据这些指令调整机器人的坐标，并检查最终坐标是否为(0,0)，以此来判断机器人是否回到了起点。

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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

My Solution:

class Solution {
    public boolean judgeCircle(String moves) {
        int x = 0;
        int y = 0;
        for(int i = 0; i < moves.length(); i++){
            if(moves.charAt(i) == 'U')
                y++;
            else if(moves.charAt(i) == 'D')
                y--;
            else if(moves.charAt(i) == 'L')
                x--;
            else if(moves.charAt(i) == 'R')
                x++;
        }
        if(x == 0 && y == 0)
            return true;
        else
            return false;
    }
}