LeetCode 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: false

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