leetcode

0 class Solution {

1 pair<int, int> offset[4] = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};

2 int limit_offset[4] = {1, -1, -1, 1};

3 int limit[4] = {0, 0, 0, 0};

4

5 int &m = limit[2], &n = limit[1];

6

7 bool valid(int i, int j) { return i >= limit[0] && i <= m && j >= limit[3] && j <= n; }

8

9 public:

10 vector<int> spiralOrder(vector<vector<int>> &matrix) {

11 vector<int> res;

12 int direction = 0;

13 int cnt = 0;

14 int size;

15 int i = 0, j = 0;

16

17 m = matrix.size() - 1;

18 n = matrix[0].size() - 1;

19 size = (m + 1) * (n + 1);

20

21 while (true) {

22 res.push_back(matrix[i][j]);

23 if (++cnt == size) break;

24

25 if (!valid(i + offset[direction].first, j + offset[direction].second)) {

26 limit[direction] += limit_offset[direction];

27 direction = (direction + 1) % 4;

28 }

29

30 i += offset[direction].first;

31 j += offset[direction].second;

32 }

33

34 return res;

35 }

36 };