leetcode

0 class Solution {

1 public:

2 bool isRobotBounded(const string &instructions) const {

3 static const int offset_x[] = {0, -1, 0, 1};

4 static const int offset_y[] = {1, 0, -1, 0};

5

6 int x = 0, y = 0, dir = 0;

7 for (const char instruction : instructions) {

8 switch (instruction) {

9 case 'G':

10 x += offset_x[dir];

11 y += offset_y[dir];

12 break;

13 case 'L': dir = dir == 3 ? 0 : dir + 1; break;

14 case 'R': dir = dir == 0 ? 3 : dir - 1; break;

15 }

16 }

17

18 return (x == 0 && y == 0) || (dir != 0);

19 }

20 };