二叉搜索树实现文件C语言(BinarySearchTree.c)

/* BinarySearchTree.c -- 二叉搜索树实现文件 */ #include <stdio.h> #include <stdlib.h> #include "BinarySearchTree.h" /* 局部函数声明 */ int Left_Is_Less_Than_Right (const Item left, const Item right) ; int Left_Is_More_Than_Right (const Item left, const Item right) ; Position Make_Node (const Item item) ; void Copy_Item_To_Node (Node * * pnode, const Item * pitem) ; /* 接口函数声明 */ void InitializeTree (Tree * ptree) { *ptree = NULL ; } int TreeIsEmpty (const Tree tree) { return NULL == tree ; } Position Find (const Tree tree, const Item item) { if (TreeIsEmpty (tree)) return NULL ; if (Left_Is_Less_Than_Right (item, tree -> item)) return Find (tree -> left, item) ; else if (Left_Is_More_Than_Right (item, tree -> item)) return Find (tree -> right, item) ; else return tree ; } Position FindMin (const Tree tree) { if (TreeIsEmpty (tree)) return NULL ; else if (NULL == tree -> left) return tree ; else return FindMin (tree -> left) ; } Position FindMax (const Tree tree) { if (TreeIsEmpty (tree)) return NULL ; else if (NULL == tree -> right) return tree ; else return FindMax (tree -> right) ; } Tree Insert (Tree tree, const Item item) { if (NULL == tree) { tree = Make_Node (item) ; if (NULL == tree) return NULL ; } else if (Left_Is_Less_Than_Right (item, tree -> item)) tree -> left = Insert (tree -> left, item) ; else if (Left_Is_More_Than_Right (item, tree -> item)) tree -> right = Insert (tree -> right, item) ; /* Else item is in the tree already; We'll do nothing */ return tree ; } Tree Delete (Tree tree, const Item item) { Position temp ; if (NULL == tree) return NULL ; else if (Left_Is_Less_Than_Right (item, tree -> item)) tree -> left = Delete (tree -> left, item) ; else if (Left_Is_More_Than_Right (item, tree -> item)) tree -> right = Delete (tree -> right, item) ; /* Found element to be deleted */ else if (tree -> left && tree -> right) { temp = FindMin (tree) ; Copy_Item_To_Node (&tree, &temp -> item) ; tree -> right = Delete (tree -> right, tree -> item) ; } /* one or zero children <- 我感觉是child, 不过不自信 */ else { temp = tree ; if (NULL == tree -> left) tree = tree -> right ; else if (NULL == tree -> right) tree = tree -> left ; free (temp) ; } return tree ; } void InorderTraversal (const Tree tree, void (* pfun) (const Item item)) { if (tree != NULL) { InorderTraversal (tree -> left, pfun) ; (* pfun) (tree -> item) ; InorderTraversal (tree -> right, pfun) ; } } void EmptyTheTree (Tree tree) { if (tree != NULL) { EmptyTheTree (tree -> left) ; EmptyTheTree (tree -> right) ; free (tree) ; } } /* 局部函数定义 */ int Left_Is_Less_Than_Right (const Item left, const Item right) { return left < right ; } int Left_Is_More_Than_Right (const Item left, const Item right) { return left > right ; } Position Make_Node (const Item item) { Node * new_node ; new_node = (Node *) malloc (sizeof (Node)) ; if (NULL == new_node) return NULL ; else { Copy_Item_To_Node (&new_node, &item) ; new_node -> left = NULL ; new_node -> right = NULL ; return new_node ; } } void Copy_Item_To_Node (Node * * pnode, const Item * pitem) { (*pnode) -> item = *pitem ; }