题目描述:
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
解题思路:
统计输入字符串中字符U和D的个数是否一样,L和R个数是否一样,若都一样,则返回到起点。
代码:
1 class Solution { 2 public: 3 bool judgeCircle(string moves) { 4 5 int u = 0; 6 int d = 0; 7 int l = 0; 8 int r = 0; 9 u = std::count(moves.begin(), moves.end(), 'U'); 10 d = std::count(moves.begin(), moves.end(), 'D'); 11 l = std::count(moves.begin(), moves.end(), 'L'); 12 r = std::count(moves.begin(), moves.end(), 'R'); 13 return (u == d) && (l == r); 14 } 15 };