输入一棵二叉搜索树，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。

// ConsoleApplication2.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "stdafx.h"
#include<iostream>
#include<vector>
#include<algorithm>
#include<numeric>
#include<list>
#include<iterator>
#include<queue>
#include<stack>
#include<algorithm>
#include<forward_list>
using namespace std;



struct TreeNode {
	int val;
	struct TreeNode *left;
	struct TreeNode *right;
	TreeNode(int x) :
	val(x), left(NULL), right(NULL) {
	}
};
class Solution {
public:
	TreeNode* Convert(TreeNode* pRootOfTree)
	{
		if (pRootOfTree == NULL) return NULL;
		vec.clear();
		node.clear();

		InOrderTraversData(pRootOfTree);
		InOrderTraversNode(pRootOfTree);

		auto valIt = vec.begin(); 
		auto nodeIt = node.begin();
		TreeNode *head=*(node.begin()); //初始化头节点
		TreeNode *pre;
		head->left = NULL;
		head->right = NULL;
		head->val = *(vec.begin());
		pre = head;  //pre指向头节点
		
		while (++valIt != vec.end() && ++nodeIt != node.end()) //将节点值赋值个node中的节点
		{
			pre->right = *(nodeIt);
			(*nodeIt)->left = pre;
			(*nodeIt)->val = *valIt;
			pre = *nodeIt;
		}
		pre->right = NULL;
		return head;
	}
   
	void printLinkL_R(TreeNode *T) //打印 测试程序是否正确
	{
		cout << "从左往右打印：" << endl;
		while (T->right != NULL)
		{
			cout << T->val << "  ";
			T = T->right;
		}
		cout << T->val << "  ";
		cout << endl;

		cout << "从右往左打印：" << endl;
		
		while (T->left != NULL)
		{
			cout << T->val << "  ";
			T = T->left;
		}
		cout << T->val << "  ";
		cout << endl;
	}

	

	vector<TreeNode *> node;
	void InOrderTraversNode(TreeNode* T)//中序遍历得到节点的值
	{
		if (T == NULL) return;
		else
		{
			InOrderTraversNode(T->left);
			node.push_back(T);
			InOrderTraversNode(T->right);
		}
	}

	vector<int> vec;
	void InOrderTraversData(TreeNode* T) //中序遍历得到T的值
	{
		if (T == NULL) return;
		else
		{

			InOrderTraversData(T->left);
			vec.push_back(T->val);
			
			InOrderTraversData(T->right);
		}
	}
	void print() //中序打印
	{
		for (auto it = vec.begin(); it != vec.end(); ++it)
			cout << *it<<" ";
		cout << endl;
	}
	void preCreate(TreeNode* &T)  //前序创建
	{
		int num;
		cin >> num;
		if (num == 0) return;
		else
		{
			T = new TreeNode(num);
			preCreate(T->left);
			preCreate(T->right);
		}
	}
};

int main()
{

	Solution so;
	TreeNode *T=NULL;
	TreeNode *copy = NULL;

	so.preCreate(T);
	cout << "创建二叉树成功！"<<endl;
	cout << "中序遍历的结果：" << endl;
	//so.InOrderTraversData(T);
	//so.print();
	copy = so.Convert(T);
	so.printLinkL_R(copy);
//	so.print();

	

	cout << endl;
	return 0;
}