线索二叉树的实现 包括先序次序遍历先序二叉树 中序次序遍历中序二叉树 将值为x的结点作为先序二叉树T的左子 中序次序线索化二叉树 后序次序线索化二叉树-Clues to the realization of binary tree, including the order of the first order binary tree traversal sequence to sequence the order of traversal of binary tree in order to value of x as the first node of the sequence of the left sub-tree T in the sequence of the second order leads-tree after the tree order of the order of clues