1）按照先序序列建立下图所示二叉树的二插链表树，结点元素类型取字符型，树的字符序列从键盘逐个输入。

2）在第1）步建立好的二叉链表树上实施前序、中序和后序递归遍历，并输出相应遍历序列。

3) 在第1) 步建立好的二叉链表树上实施前序遍历的叶子结点输出及其个数统计。

4）在第1）步建立好的二叉链表树上实施中序非递归遍历，并输出相应遍历序列(选做)

5）中序线索化第1）步所建立的二叉链表树，中序遍历所建立的线索二叉树，并输出遍历结果(选做)

-1) the establishment of a first-order sequence shown in the figure below two binary tree insert list, take junction element type character, the character sequence input　the keyboard by one tree. 2) In the first step 1) to establish a good binary tree implementation of the pre-order list, sequence and subsequent recursive traversal, and outputs a corresponding traversal sequence. 3) the establishment of a good list before binary tree traversal implementation leaf node output and the number of statistics in the first step 1). 4) Establish the first step 1) good binary tree list in order to implement the non-recursive traversal, and outputting a corresponding traversal sequences (OPTIONAL) 5) sequence of clues 1) Step list established by the binary tree, in preorder established threaded binary and output through the results (OPTIONAL)