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 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: 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; } } };