面试题 -二元查找树转变成排序的双向链表

// Tree.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <malloc.h>
#include <iostream>
using namespace std;

template<class Type>
struct BinaryNode
{
private:
    Type value;
    BinaryNode<Type> *left;
    BinaryNode<Type> *right;
public:
    BinaryNode(Type val):left(NULL),right(NULL)
    {
        value = val;
    }
    BinaryNode<Type> * GetLeftBiggest();
    BinaryNode<Type> * GetRightSmallest();
    void convert();
    void Insert(BinaryNode<Type> *ptr);
    void Print();
    void PrintList();
};

template<class Type>
void BinaryNode<Type>::Print()
{
    if(this==NULL)
    {
        return;
    }
    cout<<value<<endl;    
    left->Print();
    right->Print();
}

template<class Type>
void BinaryNode<Type>::PrintList()
{
    BinaryNode *l = left;
    BinaryNode *r = right;

    while(l->left!=NULL)
    {
        l = l->left;
    }
    while(l->right!=NULL)
    {
        cout<<l->value<<endl;
        l = l->right;
    }
    while(l->left != NULL)
    {
        cout<<l->value<<endl;
        l=l->left;
    }

}



template<class Type>
BinaryNode<Type> * BinaryNode<Type>::GetLeftBiggest()
{
    BinaryNode<Type> *result=NULL;
    if(left!= NULL)
    {
        result = left;
        while(result->right!=NULL)
        {
            result = result->right;
        }
    }
    return result;

}

template<class Type>
BinaryNode<Type> * BinaryNode<Type>::GetRightSmallest()
{
    BinaryNode<Type> *result=NULL;
    if(right!= NULL)
    {
        result = right;
        while(result->left!=NULL)
        {
            result = result->left;
        }
    }
        return result;
}

template<class Type>
void BinaryNode<Type>::convert( )
{
    if(left!=NULL)
    {
        BinaryNode<Type> *ptr = GetLeftBiggest();
        left->convert();
        ptr->right = this;
        this->left = ptr;
    }
    if(right!=NULL)
    {
        BinaryNode<Type> * ptr = GetRightSmallest();
        right->convert();
        ptr->left = this;
        this->right = ptr;
    }
}

template<class Type>
void BinaryNode<Type>::Insert(BinaryNode<Type> *ptr)
{
    if((value>=ptr->value)&&(left == NULL))
    {
        left = ptr;
        return;
    }
    else if((value>=ptr->value)&&(left != NULL))
    {
        return left->Insert(ptr);
    }
    else if((value<ptr->value)&&(right == NULL))
    {
        right = ptr;
        return;
    }
    else
    {
        return right->Insert(ptr);
    }
}

int _tmain(int argc, _TCHAR* argv[])
{
    int value;
    cout<<"Please input the root value"<<endl;
    cin>>value;
    BinaryNode<int> *root=  new BinaryNode<int>(value);;
    
    int TreeNodeNumber;
    cout<<"Please input the Tree Node Numbers:"<<endl;
    cin>>TreeNodeNumber;
    BinaryNode<int> **nodes = new BinaryNode<int> *[TreeNodeNumber];
    for(int index=0;index<TreeNodeNumber;index++)
    {
        int value;
        cout<<"Please input the "<<index+1<<" Node"<<endl;
        cin>>value;
        nodes[index] = new BinaryNode<int>(value);        
        root->Insert(nodes[index]);
    }

    root->Print();
    root->convert();
    root->PrintList();
    
    return 0;
}

参考：

http://blog.csdn.net/anialy/article/details/7645535