completion of the process of non

代码说明：

该程序完成对二叉树的非递归中序遍历，因为其中涉及到二叉树的构造，而且使用类来构造，所以代码比较多。-completion of the process of non- recursive binary tree which preorder because it involved the construction of a binary tree, but the use of class structure, the code more.