657. Judge Route Circle

Posted on Edited on

题目

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

思路

设置两个变量代表x,y轴坐标，然后对应操作就好。最后查看x，y是否还等于0。

代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
class Solution {
public:
    bool judgeCircle(string moves) {
        int x = 0,y=0;
        for(auto m:moves) {
            switch(m) {
                case 'L':x--;break;
                case 'R':x++;break;
                case 'U':y++;break;
                case 'D':y--;break;
            }
        }
        if(x == 0 && y == 0) {
            return true;
        }
        else {
            return false;
        }
    }
};