#pragma once#include <iostream>using namespace std;enum ORDER_MODE{ORDER_MODE_PREV = 0,ORDER_MODE_MID,ORDER_MODE_POST};template <class T>struct BinaryNode{T element;BinaryNode *left;BinaryNode *right;BinaryNode(const T& theElement,BinaryNode *lt,BinaryNode *rt):element(theElement),left(lt),right(rt){}};template <class T>class BinarySearchTree{private:BinaryNode<T> *m_root;public:BinarySearchTree();BinarySearchTree(const BinarySearchTree& rhs);~BinarySearchTree();const T& findMin() const;const T& findMax() const;bool contains(const T& x) const;void printTree(ORDER_MODE eOrderMode = ORDER_MODE_PREV) const;void makeEmpty();void insert(const T& x);void remove(const T& x);private://因为树的方法用到了很多递归， 所以这里我们需要申明如下的私有成员函数void insert(const T& x, BinaryNode<T>* &t) ;void remove(const T& x, BinaryNode<T>* &t) ;BinaryNode<T>* findMin( BinaryNode<T>* t) const;BinaryNode<T>* findMax( BinaryNode<T>* t) const;bool contains(const T& x, const BinaryNode<T>* t) const;void makeEmpty(BinaryNode<T>* &t);void printTreeInPrev(BinaryNode<T>* t) const;void printTreeInMid(BinaryNode<T>* t)const;void printTreeInPost(BinaryNode<T>* t)const;};template <class T>BinarySearchTree<T>::BinarySearchTree(){m_root = NULL;}template <class T>BinarySearchTree<T>:: BinarySearchTree(const BinarySearchTree& rhs){m_root = rhs.m_root;}template <class T>BinarySearchTree<T>:: ~BinarySearchTree(){makeEmpty();}// return true if the x is found in the treetemplate <class T>bool BinarySearchTree<T>::contains(const T& x) const{return contains(x, m_root);}template <class T>bool BinarySearchTree<T>::contains(const T& x, const BinaryNode<T>* t) const{if (!t)return false;else if (x < t->element)return contains(x, t->left);else if (x > t->element)return contains(x, t->right);elsereturn true;}// find the min value in the treetemplate <class T>const T& BinarySearchTree<T>::findMin() const{return findMin(m_root)->element;}template <class T>BinaryNode<T>* BinarySearchTree<T>::findMin( BinaryNode<T>* t) const{//二叉树的一个特点就是左子叶的值比根节点小， 右子叶的比根节点的大if (!t)return NULL;if (t->left == NULL)return t;elsereturn findMin(t->left);}// find the max value in the treetemplate <class T>const T& BinarySearchTree<T>::findMax() const{return findMax(m_root)->element;}template <class T>BinaryNode<T>* BinarySearchTree<T>::findMax( BinaryNode<T>* t) const{//二叉树的一个特点就是左子叶的值比根节点小， 右子叶的比根节点的大if (t != NULL)while (t->right != NULL)t = t->right;return t;}//insert an element into treetemplate <class T>void BinarySearchTree<T>:: insert(const T& x){insert(x, m_root);}template <class T>void BinarySearchTree<T>::insert(const T& x, BinaryNode<T>* &t) {if (t == NULL)t = new BinaryNode<T>(x, NULL, NULL);//注意这个指针参数是引用else if (x < t->element)insert(x, t->left);else if (x > t->element)insert(x, t->right);else;//do nothing}//remove a element int a treetemplate <class T>void BinarySearchTree<T>::remove(const T& x){return remove(x, m_root);}template <class T>void BinarySearchTree<T>::remove(const T& x, BinaryNode<T>* &t) {if (t == NULL)return;if (x < t->element)remove(x, t->left);else if (x > t->element)remove (x, t->right);else // now =={if (t->left != NULL &&t->right != NULL)//two child{t->element = findMin(t->right)->element;remove(t->element, t->right);}else{BinaryNode<T> *oldNode = t;t = (t->left != NULL) ? t->left : t->right;delete oldNode;}}}template <class T>void BinarySearchTree<T>::makeEmpty(){makeEmpty(m_root);}template <class T>void BinarySearchTree<T>::makeEmpty(BinaryNode<T>* &t){if (t){makeEmpty(t->left);makeEmpty(t->right);delete t;}t = NULL;}//Print treetemplate <class T>void BinarySearchTree<T>::printTree(ORDER_MODE eOrderMode /*= ORDER_MODE_PREV*/) const{if (ORDER_MODE_PREV == eOrderMode)printTreeInPrev(m_root);else if (ORDER_MODE_MID == eOrderMode)printTreeInMid(m_root);else if (ORDER_MODE_POST == eOrderMode)printTreeInPost(m_root);else ;//do nothing}template <class T>void BinarySearchTree<T>::printTreeInPrev(BinaryNode<T>* t) const{if (t){cout << t->element;printTreeInPrev(t->left);printTreeInPrev(t->right);}}template <class T>void BinarySearchTree<T>::printTreeInMid(BinaryNode<T>* t) const{if (t){printTreeInPrev(t->left);cout << t->element;printTreeInPrev(t->right);}}template <class T>void BinarySearchTree<T>::printTreeInPost(BinaryNode<T>* t) const{if (t){printTreeInPost(t->left);printTreeInPost(t->right);cout << t->element;}}
0 0
