LeetCode OJ：Number of Islands（孤岛计数）

 1 class Solution {
 2 public:
 3     int numIslands(vector<vector<char>>& grid) {
 4         int count = 0;
 5         if(!grid.size() || !grid[0].size())
 6             return count;
 7           int row = grid.size();
 8           int col = grid[0].size();
 9           for(int i = 0; i < row; ++i){
10               for(int j = 0; j < col; ++j){
11                   if(grid[i][j] == ‘1‘){
12                       dfs(grid, i, j);
13                       count++;
14                   }
15 
16               }
17           }
18           return count;
19     }
20 
21     void dfs(vector<vector<char>> & grid, int x, int y)
22     {
23         if(grid[x][y] == ‘1‘)
24             grid[x][y] = ‘X‘;
25         else 
26             return;
27         dfs(grid, x+1, y);
28         dfs(grid, x-1, y);
29         dfs(grid, x, y+1);
30         dfs(grid, x, y0);
31     }
32 };