二叉搜索树与双向链表

来源：互联网发布：lv男士名片夹淘宝编辑：程序博客网时间：2024/06/03 13:42

问题:输入一颗二叉搜素树，将该二叉搜索树转换成一个排序的双向链表，要求不能创建任何新的结点，只能调整树中结点指针的指向。

二叉树的结点的定义如下:

struct BinaryTreeNode

{

int m_nValue;

BinaryTreeNode * m_pLeft;

BinaryTreeNode* m_pRight;

};

举个栗子:

实现的详细代码如下:

#include "stdafx.h"#include "..\Utilities\BinaryTree.h"void ConvertNode(BinaryTreeNode* pNode, BinaryTreeNode** pLastNodeInList);BinaryTreeNode* Convert(BinaryTreeNode* pRootOfTree){    BinaryTreeNode *pLastNodeInList = NULL;    ConvertNode(pRootOfTree, &pLastNodeInList);    // pLastNodeInList指向双向链表的尾结点，    // 我们需要返回头结点    BinaryTreeNode *pHeadOfList = pLastNodeInList;    while(pHeadOfList != NULL && pHeadOfList->m_pLeft != NULL)        pHeadOfList = pHeadOfList->m_pLeft;    return pHeadOfList;}void ConvertNode(BinaryTreeNode* pNode, BinaryTreeNode** pLastNodeInList){    if(pNode == NULL)        return;    BinaryTreeNode *pCurrent = pNode;    if (pCurrent->m_pLeft != NULL)        ConvertNode(pCurrent->m_pLeft, pLastNodeInList);    pCurrent->m_pLeft = *pLastNodeInList;     if(*pLastNodeInList != NULL)        (*pLastNodeInList)->m_pRight = pCurrent;    *pLastNodeInList = pCurrent;    if (pCurrent->m_pRight != NULL)        ConvertNode(pCurrent->m_pRight, pLastNodeInList);}// ====================测试代码====================void PrintDoubleLinkedList(BinaryTreeNode* pHeadOfList){    BinaryTreeNode* pNode = pHeadOfList;    printf("The nodes from left to right are:\n");    while(pNode != NULL)    {        printf("%d\t", pNode->m_nValue);        if(pNode->m_pRight == NULL)            break;        pNode = pNode->m_pRight;    }    printf("\nThe nodes from right to left are:\n");    while(pNode != NULL)    {        printf("%d\t", pNode->m_nValue);        if(pNode->m_pLeft == NULL)            break;        pNode = pNode->m_pLeft;    }    printf("\n");}void DestroyList(BinaryTreeNode* pHeadOfList){    BinaryTreeNode* pNode = pHeadOfList;    while(pNode != NULL)    {        BinaryTreeNode* pNext = pNode->m_pRight;        delete pNode;        pNode = pNext;    }}void Test(char* testName, BinaryTreeNode* pRootOfTree){    if(testName != NULL)        printf("%s begins:\n", testName);    PrintTree(pRootOfTree);    BinaryTreeNode* pHeadOfList = Convert(pRootOfTree);    PrintDoubleLinkedList(pHeadOfList);}//            10//         /      \//        6        14//       /\        /\//      4  8     12  16void Test1(){    BinaryTreeNode* pNode10 = CreateBinaryTreeNode(10);    BinaryTreeNode* pNode6 = CreateBinaryTreeNode(6);    BinaryTreeNode* pNode14 = CreateBinaryTreeNode(14);    BinaryTreeNode* pNode4 = CreateBinaryTreeNode(4);    BinaryTreeNode* pNode8 = CreateBinaryTreeNode(8);    BinaryTreeNode* pNode12 = CreateBinaryTreeNode(12);    BinaryTreeNode* pNode16 = CreateBinaryTreeNode(16);    ConnectTreeNodes(pNode10, pNode6, pNode14);    ConnectTreeNodes(pNode6, pNode4, pNode8);    ConnectTreeNodes(pNode14, pNode12, pNode16);    Test("Test1", pNode10);    DestroyList(pNode4);}//               5//              ///             4//            ///           3//          ///         2//        ///       1void Test2(){    BinaryTreeNode* pNode5 = CreateBinaryTreeNode(5);    BinaryTreeNode* pNode4 = CreateBinaryTreeNode(4);    BinaryTreeNode* pNode3 = CreateBinaryTreeNode(3);    BinaryTreeNode* pNode2 = CreateBinaryTreeNode(2);    BinaryTreeNode* pNode1 = CreateBinaryTreeNode(1);    ConnectTreeNodes(pNode5, pNode4, NULL);    ConnectTreeNodes(pNode4, pNode3, NULL);    ConnectTreeNodes(pNode3, pNode2, NULL);    ConnectTreeNodes(pNode2, pNode1, NULL);    Test("Test2", pNode5);    DestroyList(pNode1);}// 1//  \//   2//    \//     3//      \//       4//        \//         5void Test3(){    BinaryTreeNode* pNode1 = CreateBinaryTreeNode(1);    BinaryTreeNode* pNode2 = CreateBinaryTreeNode(2);    BinaryTreeNode* pNode3 = CreateBinaryTreeNode(3);    BinaryTreeNode* pNode4 = CreateBinaryTreeNode(4);    BinaryTreeNode* pNode5 = CreateBinaryTreeNode(5);    ConnectTreeNodes(pNode1, NULL, pNode2);    ConnectTreeNodes(pNode2, NULL, pNode3);    ConnectTreeNodes(pNode3, NULL, pNode4);    ConnectTreeNodes(pNode4, NULL, pNode5);    Test("Test3", pNode1);    DestroyList(pNode1);}// 树中只有1个结点void Test4(){    BinaryTreeNode* pNode1 = CreateBinaryTreeNode(1);    Test("Test4", pNode1);    DestroyList(pNode1);}// 树中没有结点void Test5(){    Test("Test5", NULL);}int _tmain(int argc, _TCHAR* argv[]){    Test1();    Test2();    Test3();    Test4();    Test5();    return 0;}

显示的部分结果如下:

0 0