Memory usage in Reversi board state
I agree with other commenters that you should have your memory usage measured first, so you know for sure you need to solve this. That said, I don't think MinMax requires storing all board states of the tree. Why do you need to have more boards in the memory than the level of the tree search? That should be 10-15 boards in the memory tops, no? I would even think about storing just one board in the memory and passing just the "moves" down the recursion. You will perform the move when you go down the recursion and undo the move when going up.