模板类继承的小问题..
为了实现BinarySearchTree我建了两个模板类，一个为节点类(BinaryNode<Type>)，另外一个(BinarySearchTree<Type>)用来实现二叉排序树（节点类被包含在二叉排序树内）的操作。现在问题来了，我想在新定义的AVL树中重用二叉排序树的代码，但是因为要对节点类的数据成员进行更新(BinaryNode<Type>派生出的AVLNode<Type>要增加一个int hight数据成员)，我如何才能在新建增、由BinarySearchTree<Type>派生出的AVL_BinarySearchTree<Type>中将使用BinaryNode<Type>类型的地方全部更新为使用AVLNode<Type>类型？
以下为代码：
#ifndef BINARY_H#define BINARY_Htemplate <typename Type>class BinaryNode{public: Type data; BinaryNode *right, *left; BinaryNode(const Type &initElement, BinaryNode *r = 0, BinaryNode *l = 0) : right(r), left(l), data(initElement){}};template <typename Type>class BinarySearchTree{public: typedef BinaryNode<Type> BinaryNode; BinarySearchTree(); //BinarySearchTree(const BinarySearchTree&); //~BinarySearchTree(); const Type& findMin() const; const Type& findMax() const; bool contains(const Type&); void insert(const Type&); void remove(const Type&); void outPut(); private: BinaryNode *root; bool contains(const Type&, BinaryNode*); void insert(const Type&, BinaryNode*&); void remove(const Type&, BinaryNode*&); BinaryNode* findMin(BinaryNode* t) const; BinaryNode* findMax(BinaryNode*) const; void InOrder(BinaryNode*) const; //void makeEmpty(BinaryNode *t);};//#include "BinarySearchTree.cpp"#endif#include "BinarySearchTree.h"template <typename Type>BinarySearchTree<Type>::BinarySearchTree() : root(0){}////////////////////////////////////////////////////////////////////////template <typename Type>typename BinarySearchTree<Type>::BinaryNode* BinarySearchTree<Type>::findMin(BinaryNode* t) const{ if(t == 0) return 0;//ERROR if(t->left == 0) return t; else return findMin(t->left);}template <typename Type>typename BinarySearchTree<Type>::BinaryNode* BinarySearchTree<Type>::findMax(BinaryNode* t) const{ if(t == 0) return 0;//ERROR if(t->right == 0) return t; else return findMax(t->right);}template <typename Type>const Type& BinarySearchTree<Type>::findMin() const{ return findMin(root)->data;}template <typename Type>const Type& BinarySearchTree<Type>::findMax() const{ return findMax(root)->data;}////////////////////////////////////////////////////////////////////////template <typename Type>bool BinarySearchTree<Type>::contains(const Type& x){ return contains(x, root);}template <typename Type>bool BinarySearchTree<Type>::contains(const Type& x, BinaryNode* t){ if(t == 0) return false; else if(x < t->data) return contains(x, t->left); else if(x > t->data) return contains(x, t->right); else return true;}////////////////////////////////////////////////////////////////////////template <typename Type>void BinarySearchTree<Type>::insert(const Type& x){ insert(x, root);}template <typename Type>void BinarySearchTree<Type>::insert(const Type& x, BinaryNode*& t){ if(t == 0) t = new BinaryNode(x, 0, 0); else if(x < t->data) insert(x, t->left); else if(x > t->data) insert(x, t->right); else ;}////////////////////////////////////////////////////////////////////////template <typename Type>void BinarySearchTree<Type>::remove(const Type& x){ remove(x, root);}template <typename Type>void BinarySearchTree<Type>::remove(const Type& x, BinaryNode*& t){ if(t == 0) return; else if(x < t->data) remove(x, t->left); else if(x > t->data) remove(x, t->right); else if(t->left != 0 && t->right != 0) { t->data = findMin(t->right)->data; remove(t->data, t->right); } else { BinaryNode *old = t; t = (t->left != 0) ? t->left : t->right; delete old; } }////////////////////////////////////////////////////////////////////////template <typename Type>void BinarySearchTree<Type>::outPut(){ InOrder(root);}template <typename Type>void BinarySearchTree<Type>::InOrder(BinaryNode* t) const{ if(t == 0) return; if(t->left != 0) InOrder(t->left); cout<<t->data<<" "; if(t->right != 0) InOrder(t->right);}
#ifndef AVL_H#define AVL_H #include "BinarySearchTree.h"template <typename Type>class AVLNode : public BinaryNode<Type>{public: int hight; AVLNode() : hight(0){} };template <typename Type>class AVL_BinarySearchTree : public BinarySearchTree<Type>{public: typedef AVLNode<Type> BinaryNode;};#endif