线索二叉树，二叉树的中序线索化方法。建立二叉树对应的二叉链表，先将该二叉树线索化，然后用非栈非递归方式输出该二叉树的中序序列。采用二叉链表存储结构，用递归方式 -Threaded Binary Tree, inorder threaded binary tree method. The establishment of the corresponding binary tree binary list, the first clue of the binary tree, and then