public class Solution
extends Object
695 - Max Area of Island\.
Medium
You are given an `m x n` binary matrix `grid`. An island is a group of `1`'s (representing land) connected **4-directionally** (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water.
The **area** of an island is the number of cells with a value `1` in the island.
Return _the maximum **area** of an island in_ `grid`. If there is no island, return `0`.
**Example 1:**
**Input:** grid = \[\[0,0,1,0,0,0,0,1,0,0,0,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,1,1,0,1,0,0,0,0,0,0,0,0],[0,1,0,0,1,1,0,0,1,0,1,0,0],[0,1,0,0,1,1,0,0,1,1,1,0,0],[0,0,0,0,0,0,0,0,0,0,1,0,0],[0,0,0,0,0,0,0,1,1,1,0,0,0],[0,0,0,0,0,0,0,1,1,0,0,0,0]]
**Output:** 6
**Explanation:** The answer is not 11, because the island must be connected 4-directionally.
**Example 2:**
**Input:** grid = \[\[0,0,0,0,0,0,0,0]]
**Output:** 0
**Constraints:**
* `m == grid.length`
* `n == grid[i].length`
* `1 <= m, n <= 50`
* `grid[i][j]` is either `0` or `1`.