二叉查找树（binary search tree）的实现

二叉查找树的实现继承了 二叉树的实现。

//二叉查找树的头文件

#ifndef SEARCH_TREE_H_#define SEARCH_TREE_H_#include"tree_exception.h"#include"binary_tree.h"class SearchTree :public BinaryTree{public:SearchTree();SearchTree(const BinaryTree &_tree);virtual ~SearchTree();virtual void insert(const ItemType &newitem)throw(TreeException);virtual void remove(const ItemType &newitem)throw(TreeException);protected:void insertitem(TreeNode *&treePtr,const ItemType &newitem)throw(TreeException);void removeitem(TreeNode *&treePtr,const ItemType &keyitem)throw(TreeException);void removenode(TreeNode *&treePtr);void processleftmost(TreeNode *&treePtr,ItemType &_item);};#endif

//二叉查找树的实现文件

#include"search_tree.h"SearchTree::SearchTree(){}SearchTree::SearchTree(const BinaryTree &_tree):BinaryTree(_tree){}SearchTree::~SearchTree(){}void SearchTree::insert(const ItemType &newitem)throw(TreeException){try{insertitem(rootPtr(),newitem);}catch(TreeException &e){throw;}}void SearchTree::remove(const ItemType &keyitem)throw(TreeException){try{removeitem(rootPtr(),keyitem);}catch(TreeException &e){throw;}}void SearchTree::insertitem(TreeNode *&treePtr,const ItemType &newitem)throw(TreeException){if(treePtr==NULL){treePtr=new TreeNode(newitem,NULL,NULL);if(treePtr==NULL)throw TreeException("calling insert function failed :allocate memory failed ");}else if(treePtr->item>newitem){insertitem(getLeftPtr(treePtr),newitem);}elseinsertitem(getRightPtr(treePtr),newitem);}void SearchTree::removeitem(TreeNode *&treePtr,const ItemType &keyitem)throw(TreeException){if(treePtr==NULL)throw TreeException("calling remove function failed:search key item failed ");else if(treePtr->item==keyitem){removenode(treePtr);}else if(treePtr->item>keyitem){removeitem(getLeftPtr(treePtr),keyitem);}else{removeitem(getRightPtr(treePtr),keyitem);}}void SearchTree::removenode(TreeNode *&treePtr){ItemType replaceitem;if((getLeftPtr(treePtr)==NULL)&&(getRightPtr(treePtr)==NULL)){delete treePtr;treePtr=NULL;}else if(getLeftPtr(treePtr)==NULL){TreeNode *temp=treePtr;treePtr=getRightPtr(treePtr);getRightPtr(temp)=NULL;delete temp;}else if(getRightPtr(treePtr)==NULL){TreeNode *temp=treePtr;treePtr=getLeftPtr(treePtr);getLeftPtr(temp)=NULL;delete temp;}else{processleftmost(getRightPtr(treePtr),replaceitem);treePtr->item=replaceitem;}}void SearchTree::processleftmost(TreeNode *&treePtr,ItemType &_item){if(getLeftPtr(treePtr)==NULL){_item=treePtr->item;TreeNode *temp=treePtr;treePtr=getRightPtr(treePtr);getRightPtr(temp)=NULL;delete temp;}else{processleftmost(getLeftPtr(treePtr),_item);}}

//二叉查找树的测试

#include"search_tree.h"#include"binary_tree.h"#include<iostream>using namespace std;void display(ItemType &anitem);int main(){BinaryTree tree1,tree2,left;BinaryTree tree3("hello");try{tree1.setRootData("tetrach");tree1.attachLeft("creature");tree1.attachRight("vocation");cout<<"tree1 :"<<endl;tree1.postorderTraverse(display);cout<<endl;tree2.setRootData("prevail");tree2.attachLeft("dormant");tree2.attachRightSubtree(tree1);cout<<endl;cout<<"tree2 :"<<endl;tree2.inorderTraverse(display);cout<<endl;BinaryTree binTree("povit",tree2,tree3);cout<<"binTree :"<<endl;binTree.inorderTraverse(display);cout<<endl;cout<<"binTree 's left subtree :"<<endl;binTree.getLeftSubtree().preorderTraverse(display);cout<<endl;binTree.deleteLeftSubtree(left);cout<<endl;cout<<"binTree 's left subtree :"<<endl;left.inorderTraverse(display);cout<<endl<<"binTree after delete :"<<endl;binTree.preorderTraverse(display);cout<<endl;SearchTree * atree=new SearchTree();atree->insert("inheritor");atree->insert("arrogate");atree->insert("diverse");atree->insert("sacrament");cout<<endl;cout<<"atree :"<<endl;atree->inorderTraverse(display);atree->remove("arrogate");cout<<endl;cout<<"atree after removing :"<<endl;atree->inorderTraverse(display);}catch(TreeException &e){cout<<e.what()<<endl;}return 0;}void display(ItemType &anitem){cout<<anitem<<"  ";}