657. Judge Route Circle

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

 

 

给垂直方向和水平方向两个计数器，根据不同的变动进行加减，都为0说明没动。（自己第一时间想到的无脑解）

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