[数据结构]二叉树之二叉链表的类模板实现

该类模板实现了一个二叉树的模板类，採用二叉链表实现。

定义二叉树节点类，採用二叉链表实现。

/////////////////////////
#include <iostream>
#include <cstdlib>
#include <stack>
#include <deque>
using namespace std;


template<class T>
struct BinTreeNode  //二叉树节点类的定义。使用二叉链表
{
    T data;
    BinTreeNode<T> *leftChild, *rightChild;
    BinTreeNode():leftChild(NULL),rightChild(NULL){}
    BinTreeNode(T x,BinTreeNode<T> *l=NULL,BinTreeNode<T> *r=NULL):data(x),leftChild(l),rightChild(r){}
};

二叉树的模板类实现例如以下：可进行对应的功能扩展。

接口部分：

template<class T>
class BinaryTree//二叉树的模板类
{
public:
    BinaryTree():root(NULL){}
    BinaryTree(char x):root(NULL),RefValue(x){}
    BinaryTree(const BinaryTree<T>& rhs){root=copy(rhs.root);}//copy构造函数
    BinaryTree<T>& operator=(const BinaryTree<T>& rhs);//copy 赋值运算符;析构+copy构造函数  
    ~BinaryTree(){destroy(root);}//析构函数

    bool isEmpty()const{return root!=NULL?
false:true;}
    BinTreeNode<T>* leftChild(BinTreeNode<T>* current)const{return current!=NULL?current->leftChild:NULL;}
    BinTreeNode<T>* rightChild(BinTreeNode<T>* current)const{return current!=NULL?
current->rightChild:NULL;}
    BinTreeNode<T>* parent(BinTreeNode<T>* current)const{return (root==NULL || current==root)?NULL:parent(root,current);}//寻找其父节点
    BinTreeNode<T>* getRoot()const{return root;}

    void inOrder(void (*visit)(BinTreeNode<T> *p)){inOrder(root,visit);}//中序递归遍历
    void preOrder(void (*visit)(BinTreeNode<T> *p)){preOrder(root,visit);}//前序递归
    void postOrder(void (*visit)(BinTreeNode<T> *p)){postOrder(root,visit);}//后序递归
    void levelOrder(void (*visit)(BinTreeNode<T> *p));//使用队列的层次遍历

    int size()const {return size(root);}//使用后序递归遍历求节点个数
    int height()const {return height(root);}//使用后序递归遍历求二叉树的高度



protected:
    BinTreeNode<T> *root;
    char RefValue;//数据输入停止标志

    void destroy(BinTreeNode<T>* subTree);//递归删除二叉树节点。后序遍历删除
    BinTreeNode<T>* copy(const BinTreeNode<T> *orignode);//copy构造;前序

    BinTreeNode<T>* parent(BinTreeNode<T>* subTree,BinTreeNode<T>* current)const;//返回父节点
    void traverse(BinTreeNode<T>* subTree,ostream& out)const;//按前序方式遍历输出每一个节点的值
    void createBinTree(istream& in,BinTreeNode<T>* & subTree);//採用广义表表示的二叉树创建方法

    void inOrder(BinTreeNode<T> *subTree,void (*visit)(BinTreeNode<T> *p));//中序遍历
    void preOrder(BinTreeNode<T> *subTree,void (*visit)(BinTreeNode<T> *p));//前序遍历
    void postOrder(BinTreeNode<T> *subTree,void (*visit)(BinTreeNode<T> *p));//后序遍历

    int size(BinTreeNode<T> *subTree)const;//使用后序递归遍历求节点个数
    int height(BinTreeNode<T> *subTree)const;//使用后序递归遍历求二叉树的高度
    

    friend ostream& operator<< <T>(ostream& out,const BinaryTree<T>& rhs);//add <T> 前序输出二叉树
    friend istream& operator>> <T>(istream& in, BinaryTree<T>& rhs);      //add <T> 採用广义表表示方式创建二叉树

};

对应成员函数的详细实现：

template<class T>
void BinaryTree<T>::destroy(BinTreeNode<T>* subTree)
{
    if(subTree!=NULL){
        destroy(subTree->leftChild);
        destroy(subTree->rightChild);
        delete subTree;
    }
}

template<class T>
BinTreeNode<T>* BinaryTree<T>::parent(BinTreeNode<T>* subTree,BinTreeNode<T>* current)const
{
    if(subTree==NULL) return NULL;
    if(subTree->leftChild==current || subTree->rightChild==current) return subTree;
    
    BinTreeNode<T>* p;
    if((p=parent(subTree->leftChild,current))!=NULL)
        return p
    else 
        return parent(subTree->rightChild,current);
}

template<class T>
void BinaryTree<T>::traverse(BinTreeNode<T>* subTree,ostream& out)const
{
    if(subTree!=NULL){
        out<<subTree->data<<" ";
        traverse(subTree->leftChild,cout);
        traverse(subTree->rightChild,out);
    }
}

template<class T>
void BinaryTree<T>::createBinTree(istream& in,BinTreeNode<T>* & subTree)
{
    stack<BinTreeNode<T>* > s;
    subTree=NULL;
    BinTreeNode<T> *p,*t;
    unsigned int k;
    T ch;
    in>>ch;//尽管是模板类，可是眼下仅仅支持字符型，不然会报错
    while(ch!=RefValue){
        switch(ch){
        case '(': s.push(p);k=1;break;
        case ')': s.pop();break;
        case ',': k=2;break;
        default:
            p=new BinTreeNode<T>(ch);
            if(subTree==NULL)
                subTree=p;
            else if(k==1)
                {t=s.top();t->leftChild=p;}
            else
                {t=s.top();t->rightChild=p;}
        }
        in>>ch;
    }
}

template<class T>
ostream& operator<<(ostream& out,const BinaryTree<T>& rhs)
{
    rhs.traverse(rhs.root,out);
    out<<endl;
    return out;
}

template<class T>
istream& operator>>(istream& in, BinaryTree<T>& rhs)
{
    rhs.createBinTree(in,rhs.root);
    return in;
}

template<class T>
void BinaryTree<T>::inOrder(BinTreeNode<T> *subTree,void (*visit)(BinTreeNode<T> *p))
{
    if(subTree!=NULL){
        inOrder(subTree->leftChild,visit);
        visit(subTree);
        inOrder(subTree->rightChild,visit);
    }
}

template<class T>
void BinaryTree<T>::preOrder(BinTreeNode<T> *subTree,void (*visit)(BinTreeNode<T> *p))
{
    if(subTree!=NULL){
        visit(subTree);
        inOrder(subTree->leftChild,visit);
        inOrder(subTree->rightChild,visit);
    }
}

template<class T>
void BinaryTree<T>::postOrder(BinTreeNode<T> *subTree,void (*visit)(BinTreeNode<T> *p))
{
    if(subTree!=NULL){
        inOrder(subTree->leftChild,visit);
        inOrder(subTree->rightChild,visit);
        visit(subTree);
    }
}

template<class T>
int BinaryTree<T>::size(BinTreeNode<T> *subTree)const
{
    if(subTree==NULL)  return 0;
    else
        return 1+size(subTree->leftChild)+size(subTree->rightChild);
}

template<class T>
int BinaryTree<T>::height(BinTreeNode<T> *subTree)const
{
    if(subTree==NULL) return 0;
    else{
        int i=height(subTree->leftChild);
        int j=height(subTree->rightChild);
        return (i>j)?
i+1:j+1;
    }
}

template<class T>
BinTreeNode<T>* BinaryTree<T>::copy(const BinTreeNode<T> *orignode)
{
    if(orignode==NULL) return NULL;
    BinTreeNode<T> *temp=new BinTreeNode<T>;
    temp->data=orignode->data;
    temp->leftChild=copy(orignode->leftChild);
    temp->rightChild=copy(orignode->rightChild);
    return temp;
}

template<class T>
BinaryTree<T>& BinaryTree<T>::operator=(const BinaryTree<T>& rhs)
{
    this->destroy(this->root);
    this->root=copy(rhs.root);
    return *this;
}

template<class T>
void BinaryTree<T>::levelOrder(void (*visit)(BinTreeNode<T> *p))
{
    deque<BinTreeNode<T>* > dq; 
    BinTreeNode<T> *p=root;
    dq.push_back(p);
    while(!dq.empty()){
        p=dq.front();
        visit(p);
        dq.pop_front();

        if(p->leftChild!=NULL) dq.push_back(p->leftChild);
        if(p->rightChild!=NULL) dq.push_back(p->rightChild);
    }
}

測试函数：

int main(int argc, char* argv[])
{

    BinaryTree<char> b('#');
    cin>>b;
    cout<<b<<endl;

    //b.levelOrder(NULL);

    //BinaryTree<char> a('#');
    //cin>>a;
    //cout<<a<<endl;
    // b=a;
    //cout<<b<<endl;

    //BinaryTree<char> a=b;
    //cout<<a<<endl;

    //cout<<b.size()<<endl;
    //cout<<b.isEmpty()<<endl;
    //cout<<b.height()<<endl;

    system("pause");
    return 0;

}

測试结果：

a(b(c,d),e(f,g))#
a b c d e f g


请按随意键继续. . .