1631 - Path With Minimum Effort.

Medium

You are a hiker preparing for an upcoming hike. You are given heights, a 2D array of size rows x columns, where heights[row][col] represents the height of cell (row, col). You are situated in the top-left cell, (0, 0), and you hope to travel to the bottom-right cell, (rows-1, columns-1) (i.e., 0-indexed ). You can move up , down , left , or right , and you wish to find a route that requires the minimum effort.

A route's effort is the maximum absolute difference in heights between two consecutive cells of the route.

Return the minimum effort required to travel from the top-left cell to the bottom-right cell.

Example 1:

Input: heights = [1,2,2,3,8,2,5,3,5]

Output: 2

Explanation: The route of 1,3,5,3,5 has a maximum absolute difference of 2 in consecutive cells. This is better than the route of 1,2,2,2,5, where the maximum absolute difference is 3.

Example 2:

Input: heights = [1,2,3,3,8,4,5,3,5]

Output: 1

Explanation: The route of 1,2,3,4,5 has a maximum absolute difference of 1 in consecutive cells, which is better than route 1,3,5,3,5.

Example 3:

Input: heights = [1,2,1,1,1,1,2,1,2,1,1,2,1,2,1,1,2,1,2,1,1,1,1,2,1]

Output: 0

Explanation: This route does not require any effort.

Constraints:

• rows == heights.length

• columns == heights[i].length

• 1 <= rows, columns <= 100

• <code>1 <= heightsj<= 10⁶</code>