As Far from Land as Possible

Medium

Given a grid where 1 is land and 0 is water, find the water cell whose Manhattan distance to the nearest land cell is maximized, and return that distance. If the grid has no water or no land, return -1.

Example 1

Input:  grid = [[1,0,1],[0,0,0],[1,0,1]]
Output: 2

Example 2

Input:  grid = [[1,0,0],[0,0,0],[0,0,0]]
Output: 4

Constraints

• 1 <= n <= 100
• grid[i][j] is 0 or 1.