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<vector<int>> spiralMatrix(int dm, int dn, ListNode *head) {

11 vector<vector<int>> res(dm, vector<int>(dn, -1));

12 int direction = 0;

13 int cnt = 0;

14 int size;

15 int i = 0, j = 0;

16

17 m = dm - 1;

18 n = dn - 1;

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

20

21 while (true) {

22 res[i][j] = head->val;

23 head = head->next;

24 if (!head || ++cnt == size) break;

25

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

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

28 direction = (direction + 1) % 4;

29 }

30

31 i += offset[direction].first;

32 j += offset[direction].second;

33 }

34

35 return res;

36 }

37 };