LeetCode:1905. 统计子岛屿
class Solution {
public:
int countSubIslands(vector<vector<int>>& grid1, vector<vector<int>>& grid2) {
int m = grid1.size(), n = grid1[0].size();
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
//说明不是子岛
if (grid1[i][j] == 0 && grid2[i][j] == 1) {
dfs(grid2, i, j);
}
}
}
int res = 0;
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
if (grid2[i][j] == 1) {
res++;
dfs(grid2, i, j);
}
}
}
return res;
}
private:
void dfs(vector<vector<int>>& grid, int i, int j) {
int m = grid.size(), n = grid[0].size();
if (i < 0 || j < 0 || i >= m || j >= n) {
return;
}
if (grid[i][j] == 0) {
return;
}
grid[i][j] = 0;
dfs(grid, i + 1, j);
dfs(grid, i, j + 1);
dfs(grid, i - 1, j);
dfs(grid, i, j - 1);
}
};