5.　　定义二叉树两个结点的最小距离为这两个结点的最近公共祖先分别到这两个结点的路径长度之和。请设计一种方法，找出给定二叉树中任意两个结点的最小距离，可以考虑以图形显示之-5. The definition of binary tree of two nodes for a minimum distance between two nodes, respectively, the most recent public ancestors to these two nodes and the path length. Please design a method to identify a given binary tree any two nodes in a minimum distance between a graphical display could be considered the