编写五个函数，实现对二叉树的插入、复制、删除、非递归中序遍历和层序遍历操作，理解和掌握链式存储二叉树的性质和操作方法，同时进一步熟悉指针操作。-Write five functions to achieve the insertion of binary tree, copy, delete, and non-recursive preorder traversal sequence operations, understand and