中序线索树插入例程(自调整前驱后缀指针)C语言

int Insert (Tree * const ptree, const Item * const pitem){Node * new_node ;Node * parent, * scan = *ptree ;if (NULL == (new_node = Make_Node (pitem)))return 0 ;if (TreeIsEmpty (ptree)){*ptree = new_node ;(*ptree) -> left = NULL ;(*ptree) -> right = NULL ;return 1 ;}while (scan != NULL){parent = scan ;if (Left_Is_Greater_Than_Right (*pitem, scan -> item)){if (THREAD == scan -> right_tag){parent = scan ;break ;}elsescan = scan -> right ;}else if (Left_Is_Lesser_Than_Right (*pitem, scan -> item)){if (THREAD == scan -> left_tag){parent = scan ;break ;}elsescan = scan -> left ;}/*出现重复数据*/else{free (new_node) ;return 0 ;}}if (Left_Is_Greater_Than_Right (*pitem, parent -> item)){parent -> right_tag = LINK ;parent -> right = new_node ;parent -> right -> left = Find_Predecessor (ptree, parent, parent -> right) ;parent -> right -> right = Find_Successor (ptree, parent, parent -> right) ;}else{parent -> left_tag = LINK ;parent -> left = new_node ;parent -> left -> left = Find_Predecessor (ptree, parent, parent -> left) ;parent -> left -> right = Find_Successor (ptree, parent, parent -> left) ;}return 1 ;}static Node * Find_Predecessor (const Tree * const ptree, Node * const parent, const Node * const pnode) ;static Node * Find_Successor (const Tree * const ptree, Node * const parent, const Node * const pnode) ;static Node * The_Parent_Of (const Tree * const ptree, const Node * const pnode) ; Node * FindMin (const Tree * const ptree){Node * parent = NULL, * scan = *ptree ;while (scan != NULL){parent = scan ;scan = scan -> left ;}return parent ;}Node * FindMax (const Tree * const ptree){Node * parent = NULL, * scan = *ptree ;while (scan != NULL){parent = scan ;scan = scan -> right ;}return parent ;} static Node * Find_Predecessor (const Tree * const ptree, Node * const parent, const Node * const pnode){Node * predecessor ;if (pnode == parent -> left){if (pnode == FindMin (ptree))predecessor = NULL ;elsepredecessor = The_Parent_Of (ptree, parent) ;}else if (pnode == parent -> right)predecessor = parent ;return predecessor ;}static Node * Find_Successor (const Tree * const ptree, Node * const parent, const Node * const pnode){Node * successor ;if (pnode == parent -> left)successor = parent ;else if (pnode == parent -> right){if (pnode == FindMax (ptree))successor = NULL ;elsesuccessor = The_Parent_Of (ptree, parent) ;}return successor ;}static Node * The_Parent_Of (const Tree * const ptree, const Node * const pnode){Node * parent = NULL, * scan = *ptree ;while (scan != NULL){parent = scan ;if (Left_Is_Greater_Than_Right (pnode -> item, scan -> item)){if (scan -> right != NULL)if (Left_Is_Equal_To_Right (pnode -> item, scan -> right -> item))break ;scan = scan -> right ;}else if (Left_Is_Lesser_Than_Right (pnode -> item, scan -> item)){if (scan -> left != NULL)if (Left_Is_Equal_To_Right (pnode -> item, scan -> left -> item))break ;scan = scan -> left ;}else{if (*ptree == scan)parent = NULL ;break ;}}return parent ;}