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 tothe original place.

The move sequence is represented by a string. And each move is represent by a character. The valid robot moves areR (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: falss

class Solution {public:    bool judgeCircle(string moves) {        int updown = 0, leftright = 0;        for(int i = 0; i < moves.length(); ++i){            if(moves[i] == 'L'){                leftright--;            }else if(moves[i] == 'R'){                leftright++;            }else if(moves[i] == 'U'){                updown--;            }else if(moves[i] == 'D'){                updown++;            }        }        if(updown == 0 && leftright == 0){            return true;        }else{            return false;        }    }};