二叉树通过字符串方式，能够创建相应的二叉树，而且可以递归实现。同样，对于任意的二叉树，可以生成对应的字符串。包括从指定字符串形式创建二叉树（包括空树和平凡树）、将二叉树按照指定的字符串形式输出、判断是否空树、

计算二叉树的结点总数、计算二叉树的叶子总数、计算二叉树的高度，其中空树和平凡树的高度分别为0和1、前序遍历输出二叉树，逗号分隔、中序遍历输出二叉树，逗号分隔、后序遍历输出二叉树，逗号分隔、将树清空等功能-By way of binary string, you can create the corresponding binary tree, and can be implemented recursively. Similarly, for any binary tree, the corresponding string can be generated. Including the creation of a binary tree (including the empty tree and ordinary tree)　the specified string, the binary string according to the specified output to determine whether an empty tree,

The total number of computing nodes of the binary tree, calculate the total number of leaves of a binary tree, calculate the height of a binary tree, wherein the height of the empty tree and ordinary trees are 0 and 1, the former preorder output binary tree, separated by commas, preorder output binary tree, separated by commas after preorder output binary tree, separated by commas, empty tree functions