1、二叉树的创建和遍历演示

1）从键盘输入二叉树的各结点值，按先序递归方式创建二叉树

2）分别实现先序、中序、后序递归遍历二叉树

3）输出二叉树的按层次遍历序列

4）输出二叉树的中序非递归遍历下的结点访问次序-1, binary tree traversal of the creation and demonstration of 1) from the keyboard input of the binary tree node value, according to first create binary tree recursive sequence 2), respectively, to achieve the first order, in sequence, after the recursive sequence times calendar tree 3) output by the level of binary tree traversal sequence 4) output of the binary tree in order traversal non-recursive node under the access order