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
判断路径回环,就是判断L与R,U与D是否相等。这种抵消问题可以用2个标志位来记录字母出现的次数,对对应的字母出现相加减。
class Solution { public: bool judgeCircle(string moves) { int x = 0, y = 0; for (char c : moves) { if (c == ‘U‘) x++; else if (c == ‘D‘) x--; else if (c == ‘L‘) y++; else if (c == ‘R‘) y--; } return !(x || y); } }; // 19 ms
时间: 2024-10-09 01:24:14