一个好的递归算法可以实现基本的人工智能，无论下棋，还是什么.因为它可以实现一定程序的"预知未来",下面程序用了一个最鲜明的例子讲述了递归的入门难点,也就是注意点。-Recursive algorithm can achieve a good basic artificial intelligence, regardless of chess, or what, because it can achieve some degree of "predict the future", the following program uses one of the most striking examples about the recursive entry difficulty, that is, pay attention to point.