Implement A* and IDA* search to solve the 8-puzzle problem. Implemented the following heuristics:
h(n) = 0 i.e. leading to breadth-first search.
h(n) = 0 i.e. the number of misplaced tiles (excluding the blank tile).
h(n) = 0 i.e. the sum of the distance of the tiles from their goal positions (excluding the blank tile).