编写一个程序，实现二叉树的下列运算：
1) 输入一个二叉树的先序序列，生成二叉树的二叉链表;
2) 显示其先序、中序和后序遍历结果
3) 计算二叉树的叶子结点数。
4) 求二叉树的深度(Write a program to implement the following operations of a two fork tree:　　　　　　1) input a preorder sequence of a two fork tree to generate a two chain list of two forked trees.　　　　　　2) showed that the first order, the order and post order traversal results　　　　　　3) calculate the number of leaf nodal points of the two forked tree.　　　　　　4) the depth of the two forked tree)