AVL树实现文件C语言(AVLTree.c)

/* AVLTree.c -- AVL树实现文件*/#include <stdio.h>#include <stdlib.h>#include "AVLTree.h"/*局部函数声明*/static int Left_Above_And_Beyond_Right (const Item left, const Item right) ;static int Left_Is_Less_Than_Right (const Item left, const Item right) ;static Position Make_Node (const Item item) ;static void Copy_Item_To_Node (Node * * pnode, const Item * const pitem) ;static int Height_Count (Position position) ;static Position Single_Rotate_With_Left (Position K2) ;static Position Single_Rotate_With_Right (Position K2) ;static Position Double_Rotate_With_Left (Position K3) ;static Position Double_Rotate_With_Right (Position K3) ;static Max (const int num, const int the_other_num) ;/*接口函数定义*/void InitializeAVLTree (Tree * ptree){*ptree = NULL ;}int AVLTreeIsEmpty (const Tree tree){return NULL == tree ;}Position Find (const Tree tree, const Item item){if (NULL == tree)return NULL ;else if (Left_Above_And_Beyond_Right (item, tree -> item))return Find (tree -> right, item) ;else if (Left_Is_Less_Than_Right (item, tree -> item))return Find (tree -> left, item) ;/*找到该结点*/elsereturn tree ;}Position FindMax (const Tree tree){if (NULL == tree)return NULL ;else if (tree -> right != NULL)return FindMax (tree -> right) ;elsereturn tree ;}Position FindMin (const Tree tree){if (NULL == tree)return NULL ;else if (tree -> left != NULL)return FindMin (tree -> left) ;elsereturn tree ;}Tree Insert (Tree tree, const Item item){if (NULL == tree){tree = Make_Node (item) ;if (NULL == tree)return NULL ;}else if (Left_Above_And_Beyond_Right (item, tree -> item)){tree -> right = Insert (tree -> right, item) ;if (2 == Height_Count (tree -> right) - Height_Count (tree -> left)){if (Left_Above_And_Beyond_Right (item, tree -> right -> item))tree = Single_Rotate_With_Right (tree) ;elsetree = Double_Rotate_With_Right (tree) ;}}else if (Left_Is_Less_Than_Right (item, tree -> item)){tree -> left = Insert (tree -> left, item) ;if (2 == Height_Count (tree -> left) - Height_Count (tree -> right)){if (Left_Is_Less_Than_Right (item, tree -> left -> item))tree = Single_Rotate_With_Left (tree) ;elsetree = Double_Rotate_With_Left (tree) ;}}tree -> height = Max (Height_Count (tree -> left), Height_Count (tree -> right)) + 1 ;return tree ;}void PostorderTraverse (const Tree tree, void (* pfun) (const Position position)){if (tree != NULL){PostorderTraverse (tree -> left, pfun) ;(* pfun) (tree) ;PostorderTraverse (tree -> right, pfun) ;}}Tree Delete (Tree tree, const Item item){Position temp ;if (NULL == tree)/*其实可以什么都不做, 因为下面有返回.这里满足条件返回为了体现思维的逻辑性*/return NULL ;else if (Left_Above_And_Beyond_Right (item, tree -> item))tree -> right = Delete (tree -> right, item) ;else if (Left_Is_Less_Than_Right (item, tree -> item))tree -> left = Delete (tree -> left, item) ;else if (tree -> left && tree -> right){temp = FindMin (tree -> right) ;Copy_Item_To_Node (&tree, &(temp -> item)) ;tree -> right = Delete (tree -> right, tree -> item) ;}else{temp = tree ;if (NULL == tree -> left)tree = tree -> right ;else if (NULL == tree -> right)tree = tree -> left ;free (temp) ;}if (tree != NULL){tree -> height = Max (Height_Count (tree -> left), Height_Count(tree -> right)) + 1 ;if (2 == Height_Count (tree -> left) - Height_Count (tree -> right)){if (NULL == tree -> left -> right)tree = Single_Rotate_With_Left (tree) ;else if (NULL == tree -> left -> left)tree = Double_Rotate_With_Left (tree) ;/*左右全为不为NULL的情况下, 执行双旋转. 双旋转使树的数据分布更紧凑*/elsetree = Double_Rotate_With_Left (tree) ;}else if (2 == Height_Count (tree -> right) - Height_Count (tree -> left)){if (NULL == tree -> right -> left)tree = Single_Rotate_With_Right (tree) ;else if (NULL == tree -> right -> right)tree = Double_Rotate_With_Right (tree) ;elsetree = Double_Rotate_With_Right (tree) ;}}return tree ;}void EmptyTheAVLTree (Tree tree){if (tree != NULL){EmptyTheAVLTree (tree -> left) ;EmptyTheAVLTree (tree -> right) ;free (tree) ;}}/*局部函数定义*/static int Left_Above_And_Beyond_Right (const Item left, const Item right){return left > right ;}static int Left_Is_Less_Than_Right (const Item left, const Item right){return left < right ;}static Position Make_Node (const Item item){Position new_node ;new_node = (Position) malloc (sizeof (Node)) ;if (NULL == new_node)return NULL ;else{Copy_Item_To_Node (&new_node, &item) ;new_node -> height = 0 ;new_node -> left = new_node -> right = NULL ;return new_node ;}}static void Copy_Item_To_Node (Node * * pnode, const Item * const pitem){(*pnode) -> item = *pitem ;}static int Height_Count (Position position){if (NULL == position)return -1 ;elsereturn position -> height ;}static Position Single_Rotate_With_Left (Position K2){Position K1 ;K1 = K2 -> left ;K2 -> left = K1 -> right ;K1 -> right = K2 ;K2 -> height = Max (Height_Count (K2 -> left), Height_Count (K2 -> right)) + 1 ;K1 -> height = Max (Height_Count (K1 -> left), K2 -> height) + 1 ;return K1 ;}static Position Single_Rotate_With_Right (Position K2){Position K1 ;K1 = K2 -> right ;K2 -> right = K1 -> left ;K1 -> left = K2 ;K2 -> height = Max (Height_Count (K2 -> left), Height_Count (K2 -> right)) + 1 ;K1 -> height = Max (Height_Count (K1 -> right), K2 -> height) + 1 ;return K1 ;}static Position Double_Rotate_With_Left (Position K3){K3 -> left = Single_Rotate_With_Right (K3 -> left) ;return Single_Rotate_With_Left (K3) ;}static Position Double_Rotate_With_Right (Position K3){K3 -> right = Single_Rotate_With_Left (K3 -> right) ;return Single_Rotate_With_Right (K3) ;}static Max (const int num, const int the_other_num){return num >= the_other_num ? num : the_other_num ;}