public class Solution
extends Object
1162 - As Far from Land as Possible\.
Medium
Given an `n x n` `grid` containing only values `0` and `1`, where `0` represents water and `1` represents land, find a water cell such that its distance to the nearest land cell is maximized, and return the distance. If no land or water exists in the grid, return `-1`.
The distance used in this problem is the Manhattan distance: the distance between two cells `(x0, y0)` and `(x1, y1)` is `|x0 - x1| + |y0 - y1|`.
**Example 1:**
**Input:** grid = \[\[1,0,1],[0,0,0],[1,0,1]]
**Output:** 2
**Explanation:** The cell (1, 1) is as far as possible from all the land with distance 2.
**Example 2:**
**Input:** grid = \[\[1,0,0],[0,0,0],[0,0,0]]
**Output:** 4
**Explanation:** The cell (2, 2) is as far as possible from all the land with distance 4.
**Constraints:**
* `n == grid.length`
* `n == grid[i].length`
* `1 <= n <= 100`
* `grid[i][j]` is `0` or `1`