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;
};