參考 1. https://en.wikipedia.org/wiki/Alpha%E2%80%93beta_pruning 2. https://en.wikipedia.org/wiki/Minimaxv 3. [01-傳統電腦下棋](https://github.com/ccc112b/py2cs/tree/master/03-%E4%BA%BA%E5%B7%A5%E6%99%BA%E6%85%A7/08-%E9%9B%BB%E8%85%A6%E4%B8%8B%E6%A3%8B/01-%E5%82%B3%E7%B5%B1%E9%9B%BB%E8%85%A6%E4%B8%8B%E6%A3%8B)
