学步园

void PostorderThreading (Tree * const ptree) ；<br /> static void Postorder_Threading (Tree * const ptree, Node * * const previous) ;<br /> void PostorderThreadedTraversal (const Tree tree, void (* pfun) (const Item item)) ；<br /> static void A_Recursive_Function_For_Postorder_Threaded (const Tree * const ptree, const Node * const pnode) ;</p> <p>void PostorderThreading (Tree * const ptree)<br /> {<br /> Node * previous = NULL ;</p> <p> Postorder_Threading (ptree, &previous) ;<br /> }</p> <p>static void Postorder_Threading (Tree * const ptree, Node * * const previous)<br /> {<br /> if (*ptree != NULL)<br /> {<br /> Postorder_Threading (&(*ptree) -> left, previous) ;<br /> Postorder_Threading (&(*ptree) -> right, previous) ;<br /> if (NULL == (*ptree) -> left)<br /> {<br /> (*ptree) -> left_tag = THREAD ;<br /> (*ptree) -> left = *previous ;<br /> }<br /> if (*previous != NULL)<br /> if (NULL == (*previous) -> right)<br /> {<br /> (*previous) -> right_tag = THREAD ;<br /> (*previous) -> right = *ptree ;<br /> }<br /> *previous = *ptree ;<br /> }<br /> }</p> <p>void PostorderThreadedTraversal (const Tree tree, void (* pfun) (const Item item))<br /> {<br /> Node * scan = tree ;</p> <p> while (LINK == scan -> left_tag)<br /> scan = scan -> left ;<br /> while (THREAD == scan -> right_tag)<br /> {<br /> (* pfun) (scan -> item) ;<br /> scan = scan -> right ;<br /> }<br /> (* pfun) (scan -> item) ;<br /> scan = FindMin (&tree -> right) ;<br /> while (THREAD == scan -> right_tag)<br /> {<br /> (* pfun) (scan -> item) ;<br /> scan = scan -> right ;<br /> }<br /> A_Recursive_Function_For_Postorder_Threaded (&tree, scan -> right) ;<br /> }</p> <p>static void A_Recursive_Function_For_Postorder_Threaded (const Tree * const ptree, const Node * const pnode)<br /> {<br /> if (*ptree != pnode)<br /> {<br /> A_Recursive_Function_For_Postorder_Threaded (&(*ptree) -> right, pnode) ;<br /> printf ("%d ", (*ptree) -> item) ;<br /> }<br /> }<br />