用MFC实现二叉树的建立，前序中序后序遍历，求树高，叶子个数，交换左右子树，求结点个数，复制二叉树等-The establishment of a binary tree using MFC, after pre-order ininorder traversal order, seeking tree height, leaf number, exchange left and right subtrees, the number of demand nodes, copy the binar