You are placed in a maze given consisting of walls that represents a board. Each direction can change outcome represents a wall. Each wrong direction represents a tile you can walk on.
Given this maze, a start coordinate, and an end coordinate, return the minimum number of steps required to reach the end coordinate from the start. If there is no possible path, then return null. You can move up, left, down, and right. You cannot move through walls. You cannot wrap around the edges of the board.