// @Title: 岛屿数量 (Number of Islands)
// @Author: qisiii
// @Date: 2024-01-14 21:29:17
// @Runtime: 4 ms
// @Memory: 47.8 MB
// @comment: 
// @flag: 
class Solution {
    public int numIslands(char[][] grid) {
        int x = 0, y = 0, max = 0;
        while (x < grid.length) {
             y=0;
            while (y < grid[x].length) {
                Integer size = 0;
                if (grid[x][y] == '1') {
                    size = dfs(x, y, grid);
                    if(size>0){
                        max++;
                    }
                }
                y++;
            }
            x++;
        }
        return max;
    }

    int dfs(int x, int y, char[][] grid) {
        int i = 0;
        if (x >= grid.length || x < 0 || y >= grid[x].length || y < 0) {
            return 0;
        }
        if (grid[x][y] == '1') {
            i = 1;
        } else {
            return 0;
        }
        grid[x][y] = '0';
        i += dfs(x, y + 1, grid);
        i += dfs(x + 1, y, grid);
        i += dfs(x, y - 1, grid);
        i += dfs(x - 1, y, grid);
        return i;
    }
}