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
/**
* @param {string} moves
* @return {boolean}
*/
var judgeCircle = function(moves) {
"use strict";
let x = y = 0;
for (let i = 0; i < moves.length; i++) {
switch(moves[i]) {
case 'R': x++; break;
case 'L': x--; break;
case 'U': y++; break;
case 'D': y--; break;
}
}
return x === 0 && y === 0;
};