695. Max Area of Island.java

class Solution {
    public int maxAreaOfIsland(int[][] grid) {
        int row = grid.length;
        int col = grid[0].length;
        int result = 0;
        for (int i = 0; i < row; i++)
            for (int j = 0; j < col; j++) {
                if (grid[i][j] == 1)
                    result = Math.max(result, DFS(grid, i, j));
            }
        return result;
    }

    public int DFS(int[][] grid, int i, int j) {
        if (i >= grid.length || j >= grid[0].length || i < 0 || j < 0 || grid[i][j] == 0)
            return 0;
        grid[i][j] = 0;
        return 1 + DFS(grid, i, j + 1) + DFS(grid, i + 1, j) + DFS(grid, i - 1, j) + DFS(grid, i, j - 1);
    }
}