界面实现递归算法和非递归算法计算Aerman函数-Interface to achieve recursion algorithm and non-recursive algorithm Aerman function

给出解析XML文档的程序例子，可以运行，并用到递归算法，实现树结构-The function of the convenient search function are given of an XML document analysis program example, can run, and to recursion algorithm, realize the tree structure