把二元查找树转变成排序的双向链表

#include <iostream>
#include <time.h>

#define MAX_NUM 10

using namespace std;

struct BSTreeNode
{
int m_nValue;
BSTreeNode *m_pLeft;
BSTreeNode *m_pRight;
};

int count=0;

void AddTree(BSTreeNode** T, int num)
{
if (*T==NULL)
{
*T=(BSTreeNode*)malloc(sizeof(BSTreeNode));
(*T)->m_nValue=num;
(*T)->m_pLeft=NULL;
(*T)->m_pRight=NULL;
}
else if ((*T)->m_nValue>num)
{
AddTree(&((*T)->m_pLeft), num);
}
else
{
AddTree(&((*T)->m_pRight), num);
}
}

void MidTraversal(BSTreeNode* T)
{
if(T!=NULL)
{
MidTraversal(T->m_pLeft);
count++;
if (count%5==0)
{
cout<<T->m_nValue<<endl;
}
else
{
cout<<T->m_nValue<<"\t";
}

MidTraversal(T->m_pRight);
}
}

void ConvertNode(BSTreeNode* pNode, BSTreeNode** pLastNodeInList)
{
if (pNode==NULL)
{
return;
}

BSTreeNode* pCurrent=pNode;

if (pCurrent->m_pLeft!=NULL)
{
ConvertNode(pCurrent->m_pLeft, pLastNodeInList);
}

//Put the current node into the double-linked list
//pLastNodeInList<--pCurrent
//pLastNodeInList-->pCurrent
pCurrent->m_pLeft=*pLastNodeInList;
if (*pLastNodeInList!=NULL)
{
(*pLastNodeInList)->m_pRight=pCurrent;
}

*pLastNodeInList=pCurrent;

if (pCurrent->m_pRight!=NULL)
{
ConvertNode(pCurrent->m_pRight, pLastNodeInList);
}
}

void PrintList(BSTreeNode* L, int flag)
{
BSTreeNode* p=L;
while (p!=NULL)
{
count++;
if (count%5==0)
{
cout<<p->m_nValue<<endl;
}
else
{
cout<<p->m_nValue<<"\t";
}

if (1==flag)
{
p=p->m_pRight;
}
else
{
p=p->m_pLeft;
}
}
}

BSTreeNode* ConvertSolution(BSTreeNode* pHeadOfTree)
{
BSTreeNode* pLastNodeInList=NULL;
ConvertNode(pHeadOfTree, &pLastNodeInList);

cout<<"Last node is: "<<pLastNodeInList->m_nValue<<endl;
pLastNodeInList->m_pRight=NULL;

cout<<"Revert list is:\n";
PrintList(pLastNodeInList, 2);

BSTreeNode* pHeadOfList=pLastNodeInList;
while(pHeadOfList&&pHeadOfList->m_pLeft)
pHeadOfList=pHeadOfList->m_pLeft;
cout<<"Normal list is: \n";
PrintList(pHeadOfList, 1);

return pHeadOfList;
}

int main()
{
BSTreeNode* T=NULL;
int num, i;

srand((unsigned int)time(NULL));
for (i=0; i<MAX_NUM; i++)
{
num=rand()%100+1;
AddTree(&T, num);
}

cout<<"Mid reversal tree is:\n";
MidTraversal(T);

cout<<"\ndouble list is:\n";
PrintList(ConvertSolution(T), 1);

return 0;
}