nitially, 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 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 boolean judgeCircle(String moves) {
- int x = 0;
- int y = 0;
- for (char ch : moves.toCharArray()) {
- if (ch == 'U')
- y++;
- if (ch == 'D')
- y--;
- if (ch == 'L')
- x--;
- if (ch == 'R')
- x++;
- }
- return x == 0 && y== 0; // 检查是否回到了起点处
- }
- }
来源: http://www.bubuko.com/infodetail-3019024.html