題目:657. Judge Route Circle

難度:簡單

問題&範例:

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

 

中文說明:

機器人會走上下左右，如果最後回到原點回傳true

沒有就回傳false

 

做法:

很簡單，判斷例如右邊就x++上面就y++以此類推

最後(x,y)=(0,0)就true

 

以下程式碼

class Solution {
public:
    bool judgeCircle(string moves) {
        int i,x=0,y=0;
        
        for(i=0;i<moves.size();i++)
        {
            switch(moves[i])
            {//判斷上下左右
                case 'U':
                    y++;
                    break;
                case 'D':
                    y--;
                    break;
                case 'R':
                    x++;
                    break;
                case 'L':
                    x--;
                    break;
                default:
                    break;
                   
            }
        }
        if(x==0 &&y==0)return true;
        else return false;
    }
};