695. 岛屿的最大面积（DFS）

695. 岛屿的最大面积

依然DFS，加上最大值判断，跟200. 岛屿数量基本一模一样

class Solution {
	int res = Integer.MIN_VALUE;
	int[][] dir = new int[][] { { 0, 1 }, { 0, -1 }, { 1, 0 }, { -1, 0 } };
	int r;
	int c;
	int count;
	public int maxAreaOfIsland(int[][] grid) {
        if(grid.length == 0)
            return 0;
		r = grid.length;
		c = grid[0].length;
		for (int i = 0; i < r; i++) {
			for (int j = 0; j < c; j++) {
				if (grid[i][j] == 1) {
					count = 0;
					dfs(i, j, grid);
					res = Math.max(res, count);
				}
			}
		}
		return res < 0 ? 0 : res;
	}

	public int dfs(int i, int j, int[][] grid) {
		grid[i][j] = 0;
        count++ ;
		for (int[] d : dir) {
			int newx = i + d[0];
			int newy = j + d[1];
			if (newx >= 0 && newx < r && newy >= 0 && newy < c) {
				if(grid[newx][newy] == 1)
					dfs(newx, newy, grid);
			}
		}
		return count;
	}
}