【LeetCode】Judge Route Circle 判斷路徑是否成環
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) {
var result = moves.match(new RegExp('L', 'g'));
var countL = !result ? 0 : result.length;
result = moves.match(new RegExp('R' , 'g'));
var countR = !result ? 0 : result.length;
result = moves.match(new RegExp('U', 'g'));
var countU = !result ? 0 : result.length;
result = moves.match(new RegExp('D', 'g'));
var countD = !result ? 0 : result.length;
return countL == countR && countU ==countD;
};