#include "stdafx.h"
#include <iostream>
#include <stack>
#include <queue>
#include <Windows.h>
using namespace std;typedef struct _Node
{int data;struct _Node *left;struct _Node *right;bool isVisit;        //用于后序非递归遍历，表示节点是否可以访问
    _Node(){data = 0;left = NULL;right = NULL;isVisit = false;}
}Node, *PNode;//****************二叉树的递归建造********************
//约定：输入0表示该节点的子树为NULL
void RecurCreate(PNode pRoot)
{int data;cin>>data;if (0 != data){pRoot = new Node;pRoot->data = data;RecurCreate(pRoot->left);RecurCreate(pRoot->right);}
}//假定二叉树如下图所示，利用前序和中序、后序与中序可以唯一确定一棵二叉树的原理
//                       1
//                     /   \
//                    2     3
//                  / \     / \
//                 4   5   6   7
//               / \  /
//              8   9 10const int MAX_NUM = 10;                             //二叉树的节点数
int pre[MAX_NUM] = {1, 2, 4, 8, 9, 5, 10, 3, 6, 7}; //前序遍历的数组
int mid[MAX_NUM] = {8, 4, 9, 2, 10, 5, 1, 6, 3, 7}; //中序遍历的数组
int post[MAX_NUM] = {8, 9, 4, 10, 5, 2, 6, 7,3, 1}; //后序遍历的数组//获取前序数组的data在中序数组的索引
int GetPositionInMid(int data)
{for (int i = 0; i < MAX_NUM; i++){if (mid[i] == data){return i;}}
}//利用前序和中序可以唯一确定一棵二叉树
//参数说明
// pRoot   —— 需要建造节点的指针引用
// iPre    —— 表示pRoot节点的左子树（右子树）在前序数组的第一个索引
// iMid    —— 表示pRoot节点的左子树（右子树）在中序数组的第一个索引
// length  —— 表示pRoot节点的左子树（右子树）的长度
void PreAndMidRecurCreate(PNode &pRoot, int iPre, int iMid, int length)
{if (length <= 0){return;}pRoot = new Node;pRoot->data = pre[iPre];int pos = GetPositionInMid(pre[iPre]);PreAndMidRecurCreate(pRoot->left, iPre + 1, iMid, pos - iMid);PreAndMidRecurCreate(pRoot->right, iPre + (pos - iMid) + 1, pos + 1, length - (pos - iMid) - 1);
}//利用后序和中序可以唯一确定一棵二叉树
//参数说明
// pRoot   —— 需要建造节点的指针引用
// iPost   —— 表示pRoot节点的左子树（右子树）在后序数组的第一个索引
// iMid    —— 表示pRoot节点的左子树（右子树）在中序数组的第一个索引
// length  —— 表示pRoot节点的左子树（右子树）的长度
void PostAndMidRecurCreate(PNode &pRoot, int iPost, int iMid, int length)
{if (length <= 0){return;}pRoot = new Node;pRoot->data = post[iPost];int pos = GetPositionInMid(post[iPost]);PostAndMidRecurCreate(pRoot->left, iPost - 1 - (length - (pos - iMid) - 1), iMid, pos - iMid);PostAndMidRecurCreate(pRoot->right, iPost - 1, pos + 1, length - (pos - iMid) - 1);
}//****************二叉树的递归遍历********************//前序递归遍历
void PreRecurTraversal(PNode pRoot)
{if (NULL != pRoot){cout<<pRoot->data<<'\t';PreRecurTraversal(pRoot->left);PreRecurTraversal(pRoot->right);}
}//中序递归遍历
void MidRecurTraversal(PNode pRoot)
{if (NULL != pRoot){MidRecurTraversal(pRoot->left);cout<<pRoot->data<<'\t';MidRecurTraversal(pRoot->right);}
}//序后递归遍历
void PostRecurTraversal(PNode pRoot)
{if (NULL != pRoot){PostRecurTraversal(pRoot->left);PostRecurTraversal(pRoot->right);cout<<pRoot->data<<'\t';}
}//****************二叉树的非递归遍历********************//第一种前序非递归遍历
void PreTraversalOne(PNode pRoot)
{PNode pTree = pRoot;stack<PNode> s;while (!s.empty() || NULL != pTree){while (NULL != pTree){cout<<pTree->data<<'\t';s.push(pTree);pTree = pTree->left;}if (!s.empty()){pTree = s.top();s.pop();pTree = pTree->right;}}
}//第二种前序非递归遍历
void PreTraversalTwo(PNode pRoot)
{PNode pTree = pRoot;stack<PNode> s;s.push(pTree);while (!s.empty()){pTree = s.top();cout<<pTree->data<<'\t';s.pop();if (NULL != pTree->right) //1、右子树进栈
        {s.push(pTree->right);}if (NULL != pTree->left) //2、左子树进栈
        {s.push(pTree->left);}}
}//中序非递归遍历
void MidTraversal(PNode pRoot)
{PNode pTree = pRoot;stack<PNode> s;while (!s.empty() || NULL != pTree){while (NULL != pTree){s.push(pTree);pTree = pTree->left;}if (!s.empty()){pTree = s.top();cout<<pTree->data<<'\t';s.pop();pTree = pTree->right;}}
}//后序非递归遍历
void PostTraversal(PNode pRoot)
{PNode pTree = pRoot;stack<PNode> s;while (!s.empty() || NULL != pTree){while (NULL != pTree){s.push(pTree);pTree = pTree->left;}if (!s.empty()){pTree = s.top();if (pTree->isVisit){cout<<pTree->data<<'\t';s.pop();pTree = NULL;}else{pTree->isVisit = true;pTree = pTree->right;}}}
}//层序非递归遍历——用队列,注意与第二种非递归前序遍历的区别
void LevelTraversal(PNode pRoot)
{PNode pTree = pRoot;queue<PNode> q;q.push(pTree);while (!q.empty()){pTree = q.front();q.pop();cout<<pTree->data<<'\t';if (NULL != pTree->left)  //1、左子树进队列
        {q.push(pTree->left);}if (NULL != pTree->right) //2、右子树进队列
        {q.push(pTree->right);}}
}//辅助函数，设置控制台的颜色
void SetConsoleTextColor(WORD dwColor)
{HANDLE handle = GetStdHandle(STD_OUTPUT_HANDLE);if (INVALID_HANDLE_VALUE == handle){return;}SetConsoleTextAttribute(handle, dwColor);
}int _tmain(int argc, _TCHAR* argv[])
{PNode pRoot1 = NULL;PNode pRoot2 = NULL;cout<<endl<<"******************根据前序和中序建造二叉树********************"<<endl<<endl;PreAndMidRecurCreate(pRoot1, 0, 0, MAX_NUM);SetConsoleTextColor(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_INTENSITY);cout<<endl<<"******************层序遍历二叉树********************"<<endl<<endl;LevelTraversal(pRoot1);SetConsoleTextColor(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_INTENSITY);cout<<endl<<"******************递归遍历二叉树********************"<<endl<<endl;cout<<endl<<"       **********前序递归遍历二叉树**********"<<endl<<endl;PreRecurTraversal(pRoot1);cout<<endl<<"       **********中序递归遍历二叉树**********"<<endl<<endl;MidRecurTraversal(pRoot1);cout<<endl<<"       **********后序递归遍历二叉树**********"<<endl<<endl;PostRecurTraversal(pRoot1);SetConsoleTextColor(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);cout<<endl<<"******************根据后序和中序建造二叉树********************"<<endl<<endl;PostAndMidRecurCreate(pRoot2, MAX_NUM - 1, 0, MAX_NUM);SetConsoleTextColor(FOREGROUND_GREEN | FOREGROUND_INTENSITY);cout<<endl<<"******************非递归遍历二叉树********************"<<endl<<endl;cout<<endl<<"       **********前序非递归遍历二叉树**********"<<endl<<endl;PreTraversalOne(pRoot2);cout<<endl;PreTraversalTwo(pRoot2);cout<<endl<<"       **********中序非递归遍历二叉树**********"<<endl<<endl;MidTraversal(pRoot2);cout<<endl<<"       **********后序非递归遍历二叉树**********"<<endl<<endl;PostTraversal(pRoot2);return 0;
}