Judge Route Circle

Judge Route Circle string

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

Judge Route Circle Solution

class JudgeRouteCircle {
    public boolean judgeCircle(String moves) {
        int UD = 0;
        int LR = 0;
        for(int i = 0; i < moves.length(); i++) {
            if(moves.charAt(i) == 'U') {
                UD++;
            } else if(moves.charAt(i) == 'D') {
                UD--;
            } else if(moves.charAt(i) == 'L') {
                LR++;
            } else if(moves.charAt(i) == 'R') {
                LR--;
            }
        }

        return UD == 0 && LR == 0;
    }
}

Last modified October 4, 2020