Given an m x n matrix of positive integers representing the height of each unit cell in a 2D elevation map, compute the volume of water it is able to trap after raining.
Note:
Both m and n are less than 110. The height of each unit cell is greater than 0 and is less than 20,000.
Example:
Given the following 3x6 height map:
[
[1,4,3,1,3,2],
[3,2,1,3,2,4],
[2,3,3,2,3,1]
]
Return 4.
The above image represents the elevation map [[1,4,3,1,3,2],[3,2,1,3,2,4],[2,3,3,2,3,1]] before the rain.
After the rain, water is trapped between the blocks. The total volume of water trapped is 4.
407. Trapping Rain Water II
Difficulty: Hard
Given an
m x nmatrix of positive integers representing the height of each unit cell in a 2D elevation map, compute the volume of water it is able to trap after raining.Note:
Both m and n are less than 110. The height of each unit cell is greater than 0 and is less than 20,000.
Example:
The above image represents the elevation map
[[1,4,3,1,3,2],[3,2,1,3,2,4],[2,3,3,2,3,1]]before the rain.After the rain, water is trapped between the blocks. The total volume of water trapped is 4.