把二元查找樹轉變成排序的雙向鏈表

題目：
輸入一棵二元查找樹，將該二元查找樹轉換成一個排序的雙向鏈表。
要求不能創建任何新的結點，只調整指針的指向。
   10
  / \
  6  14
 / \ / \
4  8 12 16
 轉換成雙向鏈表
4=6=8=10=12=14=16。
 
 首先我們定義的二元查找樹 節點的數據結構如下：
 struct BSTreeNode
{
  int m_nValue; // value of node
  BSTreeNode *m_pLeft; // left child of node
  BSTreeNode *m_pRight; // right child of node

};

#include<iostream>
#include<iomanip>
using namespace std;
//
struct BSTreeNode
{
int m_nValue; // value of node
BSTreeNode *m_pLeft; // left child of node,      pre
BSTreeNode *m_pRight; // right child of node,    next
};

BSTreeNode  * Min(BSTreeNode *&tp)
{

     if(NULL==tp->m_pLeft)
     {
         BSTreeNode  * ret=tp;
         if(NULL!=tp->m_pRight)
         {
             tp=tp->m_pRight;
         }
         else
         {
             tp=NULL;
         }
         return ret;
     }
     else
     {
         BSTreeNode  * p2=tp; //fu
         BSTreeNode  * p1=p2->m_pLeft;//zi
         while(p1->m_pLeft)
         {
             p2=p1;
             p1=p1->m_pLeft;
         }
         p2->m_pLeft=p1->m_pRight;
         return p1;
     }
}

BSTreeNode  *TreetoList(BSTreeNode *tp)
//返回生成的鏈表指針 
{
     if(!tp)
     return NULL;
     else
     {
         BSTreeNode  *lp=Min(tp);
         BSTreeNode  *tem;
         lp->m_pLeft=lp->m_pRight=NULL;
         while(tp)
         {
            tem=Min(tp);
            lp->m_pRight=tem;
            tem->m_pLeft=lp;
            lp=tem;
         }
       return lp;   
     }
     
}
int main()
{
    
    system("pause");
    return 0;
    }

採用遞歸

struct BSTreeNode
{
int m_nValue; // value of node
BSTreeNode *m_pLeft; // left child of node
BSTreeNode *m_pRight; // right child of node
};

BSTreeNode *ConvertNode(BSTreeNode * p_node , bool b)
{
   if(!p_node)  return NULL;
   BSTreeNode * p_left=NULL;
   BSTreeNode * p_right=NULL;
   if(p_node->m_pLeft)
     p_left=ConvertNode(p_node->m_pLeft,false);
   if(p_left)
     {
        p_left->m_pRight=p_node;
        p_node->m_pLeft=p_left;
     }
   if(p_node->m_pRight)
     p_right=ConvertNode(p_node->m_pRight,true);
   if(p_right)
     {
        p_node->m_pRight=p_right;
        p_right->m_pLeft=p_node;
     }
   if(b)
   {
        while(p_node->m_pLeft)
           p_node=p_node->m_pLeft;
   }
   else
   {
       while(p_node->m_pRight)
           p_node=p_node->m_pRight;
   }
   return p_node;
}

BSTreeNode * Convert(BSTreeNode * t)
{
    return ConvertNode(t,true);
}

int main()
{

    system("pause");
    return 0;
    }