自顶向下伸展树实现文件C语言

/*SplayTree.c -- 自顶向下伸展树实现文件*/#include "SplayTree.h"/*外部变量引用*/extern Node * NullNode ;/*局部函数声明*/static Node * singleRotateWithLeft (Node * const position) ;static Node * singleRotateWithRight (Node * const position) ;static void upDataLeftSubTreeCount (Node * const headerRight) ;static void upDataRightSubTreeCount (Node * const headerLeft) ;static Node * splay (Node * root, const Item * const pi) ;static void release (Node * const root) ;/*接口函数定义*/BOOL Create_S (SplayTree * const pst){NullNode = (Node *) malloc (sizeof (Node)) ;if (NULL == NullNode)return FALSE ;*pst = (struct splayTree *) malloc (sizeof (struct splayTree)) ;if (NULL == *pst){free (NullNode) ;NullNode = NULL ;return FALSE ;}else{NullNode -> left = NullNode -> right = NullNode ;NullNode -> leftSubTreeCount = NullNode -> rightSubTreeCount = 0 ;(*pst) -> root = NullNode ;(*pst) -> current = 0 ;return TRUE ;}}BOOL IsEmpty_S (const SplayTree * const pst){if (NullNode == (*pst) -> root)return TRUE ;elsereturn FALSE ;}BOOL Insert_S (const SplayTree * const pst, const Item * const pi){static Node * newNode = NULL ;Node * root ;/*If it had tried to insert a item that has been inserted to the tree just now,*//*it won't need allocate memory space.*/if (NULL == newNode){newNode = (Node *) malloc (sizeof (Node)) ;if (NULL == newNode)return FALSE ;}newNode -> item = *pi ;if (NullNode == (*pst) -> root){newNode -> left = newNode -> right = NullNode ;newNode -> leftSubTreeCount = newNode -> rightSubTreeCount = 0 ;(*pst) -> root = newNode ;}else{(*pst) -> root = splay ((*pst) -> root, pi) ;root = (*pst) -> root ;if (*pi < root -> item){newNode -> leftSubTreeCount = root -> leftSubTreeCount ;newNode -> left = root -> left ;root -> leftSubTreeCount = 0 ;root -> left = NullNode ;newNode -> rightSubTreeCount = root -> rightSubTreeCount + 1 ;newNode -> right = root ;(*pst) -> root = newNode ;}else if (*pi > (*pst) -> root -> item){newNode -> rightSubTreeCount = root -> rightSubTreeCount ;newNode -> right = root -> right ;root -> rightSubTreeCount = 0 ;root -> right = NullNode ;newNode -> leftSubTreeCount = root -> leftSubTreeCount + 1 ;newNode -> left = root ;(*pst) -> root = newNode ;}else/*Already in the tree.*/return FALSE ;}/*So next insert will call malloc.*/newNode = NULL ;(*pst) -> current++ ;return TRUE ;}Node * Retrieve_S (const SplayTree * const pst){if (IsEmpty_S (pst))return NULL ;elsereturn (*pst) -> root ;}BOOL Find_S (const SplayTree * const pst, const Item * const pi){splay ((*pst) -> root, pi) ;if (*pi == (*pst) -> root -> item)return TRUE ;elsereturn FALSE ;}Node * FindKthMin_S (const SplayTree * const pst, int k){Node * scan ;if (k > (*pst) -> current || k <= 0)return NULL ;scan = (*pst) -> root ;while (1){if (scan -> leftSubTreeCount + 1 == k)break ;else if (scan -> leftSubTreeCount >= k)scan = scan -> left ;else{k = k - scan -> leftSubTreeCount - 1 ;scan = scan -> right ;}}/*Not must to do.*/(*pst) -> root = splay ((*pst) -> root, &scan -> item) ;return scan ;}Node * FindKthMax_S (const SplayTree * const pst, int k){Node * scan ;if (k > (*pst) -> current || k <= 0)return NULL ;scan = (*pst) -> root ;while (1){if (scan -> rightSubTreeCount + 1 == k)break ;else if (scan -> rightSubTreeCount >= k)scan = scan -> right ;else{k = k - scan -> rightSubTreeCount - 1 ;scan = scan -> left ;}}(*pst) -> root = splay ((*pst) -> root, &scan -> item) ;return scan ;}Node * FindMin_S (const SplayTree * const pst){Node * scan = (*pst) -> root ;while (scan -> left != NullNode)scan = scan -> left ;return scan ;}Node * FindMax_S (const SplayTree * const pst){Node * scan = (*pst) -> root ;while (scan -> right != NullNode)scan = scan -> right ;return scan ;}BOOL Delete_S (const SplayTree * const pst, const Item * const pi){Node * root ;if (IsEmpty_S (pst))return FALSE ;(*pst) -> root = splay ((*pst) -> root, pi) ;root = (*pst) -> root ;if (*pi == root -> item){/*Found it!*/if (NullNode == root -> left)(*pst) -> root = root -> right ;else{(*pst) -> root = root -> left ;/*To set (*pst) -> root -> right = NullNode.*/(*pst) -> root = splay ((*pst) -> root, pi) ;(*pst) -> root -> right = root -> right ;}free (root) ;(*pst) -> current-- ;return TRUE ;}elsereturn FALSE ;}void Traversal_S (const Node * const pr, void (* pfun) (const Node * const pn)){if (pr != NullNode){Traversal_S (pr -> left, pfun) ;(* pfun) (pr) ;Traversal_S (pr -> right, pfun) ;}}void Release_S (const SplayTree * const pst){release ((*pst) -> root) ;free (*pst) ;free (NullNode) ;}/*局部函数定义*/static Node * singleRotateWithLeft (Node * const position){Node * child ;child = position -> left ;position -> leftSubTreeCount = child -> rightSubTreeCount ;position -> left = child -> right ;child -> rightSubTreeCount = position -> leftSubTreeCount + position -> rightSubTreeCount + 1 ;child -> right = position ;return child ;}static Node * singleRotateWithRight (Node * const position){Node * child ;child = position -> right ;position -> rightSubTreeCount = child -> leftSubTreeCount ;position -> right = child -> left ;child -> leftSubTreeCount = position -> leftSubTreeCount + position -> rightSubTreeCount + 1 ;child -> left = position ;return child ;}static void upDataLeftSubTreeCount (Node * const headerRight){if (headerRight != NullNode){if (headerRight -> left != NullNode){upDataLeftSubTreeCount (headerRight -> left) ;headerRight -> leftSubTreeCount = headerRight -> left -> leftSubTreeCount + headerRight -> left -> rightSubTreeCount + 1 ;}elseheaderRight -> leftSubTreeCount = 0 ;}}static void upDataRightSubTreeCount (Node * const headerLeft){if (headerLeft != NullNode){if (headerLeft -> right != NullNode){upDataRightSubTreeCount (headerLeft -> right) ;headerLeft -> rightSubTreeCount = headerLeft -> right -> leftSubTreeCount + headerLeft -> right -> rightSubTreeCount + 1 ;}elseheaderLeft -> rightSubTreeCount = 0 ;}}/*NullNode -> leftSubTreeCount = NullNode -> rightSubTreeCount = 0.*/static Node * splay (Node * root, const Item * const pi){Node header ;Node * left_tree_max, * right_tree_min ;header.left = header.right = NullNode ;left_tree_max = right_tree_min = &header ;NullNode -> item = *pi ;while (*pi != root -> item){if (*pi < root -> item){if (*pi < root -> left -> item)root = singleRotateWithLeft (root) ;if (NullNode == root -> left)break ;/*Link right.*/right_tree_min -> left = root ;right_tree_min = root ;root = root -> left ;}else{if (*pi > root -> right -> item)root = singleRotateWithRight (root) ;if (NullNode == root -> right)break ;/*Link left.*/left_tree_max -> right = root ;left_tree_max = root ;root = root -> right ;}}/*Reassemble.*/left_tree_max -> right = root -> left ;right_tree_min -> left = root -> right ;root -> left = header.right ;root -> right = header.left ;upDataLeftSubTreeCount (root -> right) ;upDataRightSubTreeCount (root -> left) ;if (root -> left != NullNode)root -> leftSubTreeCount = root -> left -> leftSubTreeCount + root -> left -> rightSubTreeCount + 1 ;elseroot -> leftSubTreeCount = 0 ;if (root -> right != NullNode)root -> rightSubTreeCount = root -> right -> leftSubTreeCount + root -> right -> rightSubTreeCount + 1 ;elseroot -> rightSubTreeCount = 0 ;return root ;}static void release (Node * const root){if (root != NullNode){release (root -> left) ;release (root -> right) ;free (root) ;}}