695. Max Area of Island

Link

Solution

 public int maxAreaOfIsland(int[][] grid) {
        int m = grid.length;
        if(m == 0) return 0;
        int n = grid[0].length;
        int max = 0;
        for(int i = 0; i < m; i++){
            for(int j = 0; j < n; j++){
                if(grid[i][j] == 0) continue;
                max = Math.max(max, dfs(grid, i, j));
            }
        }
        return max;
    }
    
    public int dfs(int[][] grid, int i, int j){
        int m = grid.length, n = grid[0].length;
        if(i < 0 || i >= m || j < 0 || j >= n || grid[i][j] == 0) return 0;
        
        grid[i][j] = 0;
        return 1 + dfs(grid, i+1, j) + dfs(grid, i-1, j) + dfs(grid, i, j+1) + dfs(grid, i, j-1);
        
    }