leetcode

0 class Solution {

1 public:

2 int numIslands(vector<vector<char>> &grid) {

3 queue<pair<int, int>> q;

4 int cnt = 0;

5 int m = grid.size(), n = grid[0].size();

6 for (int i = 0; i < m; i++) {

7 for (int j = 0; j < n; j++) {

8 if (grid[i][j] == '0') continue;

9 q.push(make_pair(i, j));

10 cnt++;

11 while (!q.empty()) {

12 int i = q.front().first;

13 int j = q.front().second;

14 q.pop();

15 if (i < 0 || i >= m || j < 0 || j >= n || grid[i][j] == '0') continue;

16 grid[i][j] = '0';

17 q.push(make_pair(i + 1, j));

18 q.push(make_pair(i - 1, j));

19 q.push(make_pair(i, j + 1));

20 q.push(make_pair(i, j - 1));

21 }

22 }

23 }

24 return cnt;

25 }

26 };