I'm back to storing 4x4 possible board states to MongoDB. If you recall from the previous posts, I spent days working on what I thought was the solution, when in fact I was attempting to store trillions of board states which contained a lot of redundancy. I removed alpha-beta pruning and added memoization using MongoDB to read/write board states and its respective best scores. The best thing about using memoization and MongoDB is that if I were to stop the method, I won't lose the work it has previously done. I can stop and resume at any time. I'm in the process of optimizing the Negamax algorithm; Micah pointed out that my code was creating new arrays at each recursive call which allocates memory for each array. Instead of creating new arrays for every board, I plan to "undo" the board move when it's completed the score for that move. This should speed things along. It's been running almost half a day and has only stored ~310,000 board states vs. the ~130 million it used to store. It's either running a lot slower than the previous algorithm or there's a lot of redundancy.
I'm also in the process of making my RSpec tests pass again. When I was working on the UI story and changing the GUI around, my tests that were looking for those GUI fields started to fail. I have a bad habit of leaving a story and working on another and not remember what I did in the previous story. I plan to focus my time today to fix these failing RSpec tests.