根据二叉树的抽象数据类型的定义，使用二叉链表实现一个二叉树。

二叉树的基本功能：

1、二叉树的建立

2、前序遍历二叉树

3、中序遍历二叉树

4、后序遍历二叉树

5、按层序遍历二叉树

6、求二叉树的深度

7、求指定结点到根的路径

8、二叉树的销毁

-According to the abstract data type binary definition, use two forks to implement a binary tree list. The basic function of a binary tree: 1, build the binary tree 2, 3, before traversing a binary tree, binary tree traversal in the order 4, 5, after traversing a binary tree, binary tree traversal according to the sequence 6, find binary tree of depth 7, find the specified path to the root node 8, the destruction of binary tree