leetcode

0 class Solution {

1 public:

2 int minimumObstacles(vector<vector<int>> &grid) const {

3 const int n = size(grid), m = size(grid[0]);

4

5 vector<vector<int>> d(n, vector(m, INT_MAX / 2));

6 deque<pair<int, int>> dq = {{0, 0}};

7

8 static const int offset[] = {-1, 0, 1, 0, -1};

9 const auto valid = [&](int x, int y) { return x >= 0 && x < n && y >= 0 && y < m; };

10

11 for (d[0][0] = 0; !dq.empty();) {

12 const auto [a, b] = dq.front();

13 dq.pop_front();

14

15 for (int k = 0; k < 4; k++) {

16 const int x = a + offset[k + 1];

17 const int y = b + offset[k];

18

19 if (!valid(x, y) || d[x][y] != INT_MAX / 2) continue;

20 if (d[a][b] + grid[x][y] >= d[x][y]) continue;

21

22 d[x][y] = d[a][b] + grid[x][y];

23

24 if (grid[x][y] == 1)

25 dq.emplace_back(x, y);

26 else

27 dq.emplace_front(x, y);

28 }

29 }

30

31 return d[n - 1][m - 1];

32 }

33 };