Gravity connect four AI with Monte Carlo Tree Search(MCTS) and Upper Confidence bounds applied to Trees(UCT).

Import nodes pool to reduce the time used to allocate space, which will be destructed when the decision is made.

The win rate against 90.so is over 90%, against 94.so is about 60%, 100.so is about 30%.

Some of ideas are learned from https://github.com/duzx16/Connect4AI