实现一个搜索二叉树

先来看代码：

BinaryTree.h

#ifndef _BINARY_TREE_#define _BINARY_TREE_class BinaryTree{private:class Node{public:Node(int);int data_;Node *left_;Node *right_;};Node *root_;int size_;void delete_func(Node*);void preOrder_func(Node*);void inOrder_func(Node*);void postOrder_func(Node*);Node* getSuccessor(Node *del);public:BinaryTree();~BinaryTree();bool insert(int data);int size();Node* find(int data);bool deleteNode(int data);void preOrder();void inOrder();void postOrder();void displayTree();};#endif //_BINARY_TREE_

BinaryTree.cpp

#include <iostream>#include <stack>#include "BinaryTree.h"//Node类的构造函数BinaryTree::Node::Node(int data):data_(data),left_(0),right_(0){}//二叉树的构造函数BinaryTree::BinaryTree():root_(0),size_(0){}//二叉树的析构函数BinaryTree::~BinaryTree(){delete_func(root_);}//析构函数要调用的private函数void BinaryTree::delete_func(Node* node){if(node == 0)return;else{delete_func(node->left_);delete_func(node->right_);delete node;}}//往二叉树添加元素bool BinaryTree::insert(int data){Node *newNode = new Node(data);if(root_ == 0){root_ = newNode;++size_;return true;}else{Node *parent = root_;Node *current = root_;bool isleft;while(current != 0){parent = current;if(current->data_ == data)return false;else if(current->data_ > data){isleft = true;current = current->left_;}else{isleft = false;current = current->right_;}}if(isleft){parent->left_ = newNode;}else{parent->right_ = newNode;}++size_;return true;}}//二叉树的大小int BinaryTree::size(){return size_;}//前、中、后遍历二叉树的private方法void BinaryTree::preOrder_func(Node* node){if(node == 0)return;else{std::cout << node->data_ << ",";preOrder_func(node->left_);preOrder_func(node->right_);}}void BinaryTree::inOrder_func(Node* node){if(node == 0)return;else{inOrder_func(node->left_);std::cout << node->data_ << ",";inOrder_func(node->right_);}}void BinaryTree::postOrder_func(Node* node){if(node == 0)return;else{postOrder_func(node->left_);postOrder_func(node->right_);std::cout << node->data_ << ",";}}//前、中、后遍历二叉树void BinaryTree::preOrder(){preOrder_func(root_);std::endl(std::cout);}void BinaryTree::inOrder(){inOrder_func(root_);std::endl(std::cout);}void BinaryTree::postOrder(){postOrder_func(root_);std::endl(std::cout);}//二叉树的查找方法BinaryTree::Node *BinaryTree::find(int data){Node *current = root_;if(root_ == 0){return 0;}while(current->data_ != data){if(current->data_ > data)current = current->left_;elsecurrent= current->right_;if(current == 0)return 0;}return current;}//二叉树的删除方法bool BinaryTree::deleteNode(int data){Node* parent = root_;Node* current = root_;bool isLeft;if(root_ == 0){return false;}while(current->data_ != data){parent = current;if(current->data_ > data){current = current->left_;isLeft = true;}else{current = current->right_;isLeft = false;}if(current == 0)return false;}if(current->left_ == 0 && current->right_ == 0){if(current == root_){root_ = 0;}else if(isLeft){parent->left_ = 0;}else{parent->right_ = 0;}delete current;}else if(current->left_ == 0){if(current == root_){root_ = current->right_;}else if(isLeft){parent->left_ = current->right_;}else{parent->right_ = current->right_;}delete current;}else if(current->right_ == 0){if(current == root_){root_ = current->left_;}else if(isLeft){parent->left_ = current->left_;}else{parent->right_ = current->left_;}delete current;}else{Node *successor = this->getSuccessor(current);if(current == root_){root_ = successor;}else if(isLeft){parent->left_ = successor;}else{parent->right_ = successor;}successor->left_ = current->left_;delete current;}--this->size_;return true;}//查找继任节点的private方法BinaryTree::Node* BinaryTree::getSuccessor(Node *del){Node *successorParent = del;Node *successor = del;Node *current = del->right_;while(current != 0){successorParent = successor;successor = current;current = current->left_;}if(successor != del->right_){successorParent->left_ = successor->right_;successor->right_ = del->right_;}return successor;}//显示树void BinaryTree::displayTree(){std::stack<Node*> globalStack;globalStack.push(root_);int nBlanks = 32;bool isRowEmpty = false;std::cout << ".................................................." << std::endl;while(isRowEmpty == false){std::stack<Node*> localStack;isRowEmpty = true;for(int j=0;j<nBlanks;++j){std::cout << " ";}while(globalStack.empty() == false){Node *tmp = globalStack.top();globalStack.pop();if(tmp != 0){std::cout << tmp->data_;localStack.push(tmp->left_);localStack.push(tmp->right_);if(tmp->left_ != 0 || tmp->right_ != 0)isRowEmpty = false;}else{std::cout << "--";localStack.push(0);localStack.push(0);}for(int j=0; j<nBlanks*2 - 2; ++j)std::cout << " ";}std::cout << std::endl;nBlanks /= 2;while(localStack.empty() == false){globalStack.push(localStack.top());localStack.pop();}}std::cout << ".................................................." << std::endl;}

试验代码：

BinaryTree_app.cpp

#include <iostream>#include "BinaryTree.h"int main(){BinaryTree bt;std::cout << bt.size() << std::endl;bt.insert(5);bt.insert(4);bt.insert(6);bt.insert(3);bt.insert(7);bt.insert(2);bt.insert(8);bt.insert(1);std::cout << bt.size() << std::endl;bt.displayTree();bt.deleteNode(3);bt.displayTree();return 0;}

注意：在删除时，如果要删除的节点既有左子节点，又又右子节点，则找此节点的后继结点，后继结点是：所有比此结点大的节点中最小的一个。

在显示节点的方法中，还可以把此方法改造成“非递归方法遍历二叉树”