Pacific and Atlantic Water Flow
Calculate water flow from a matrix to the Pacific and Atlantic oceans.
Input: heights = [[2,1],[1,2]]
Output: [[0,0],[0,1],[1,0],[1,1]]
Explanation: All cells can flow to both oceans because water can move to adjacent cells of equal or lower height or directly off the edges.

Question

Calculate water flow from a matrix to the Pacific and Atlantic oceans.

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

Output: [[0,0],[0,1],[1,0],[1,1]]

Explanation: All cells can flow to both oceans because water can move to adjacent cells of equal or lower height or directly off the edges.