Develop minimax algorithm

[huiwang]

Both Caribbean and Code4life winner strategy are based on minimax algo.

https://github.com/Agade09/Agade-Code-4-Life-Postmortem/blob/master/Agade_C4L_Postmortem.md

https://recursive.cc/blog/coders-of-the-carribean-post-mortem.html

TODO :

• performance checks
• prune branches from root
• real game tests (connect4 ? need a game with a working heuristic)
• iterative deepening

[tyrcho]

#26

[huiwang]

@tyrcho I realized that what you've implemented is actually a negamax algo. Is it right?

[tyrcho]

Yep, this is the alpha beta optimization of negamax.