根据先序和中序重建二叉树并输出后序(不完美版)

        存在的问题：若根据先序遍历结果和中序遍历结果无法重建二叉树应该输出NO。但是它还做不到。

代码如下：

#include <stdio.h>
#include<iostream>
using namespace std;

typedef struct ListNode{
	int value;
	struct ListNode* pLeftChild;
	struct ListNode* pRightChild;

}ListNode;

void lastSearch(ListNode *pHead)
{
	if(pHead!=NULL)
	{
		
		if(pHead->pLeftChild!=NULL)
		{
		lastSearch(pHead->pLeftChild);
		}
		
		if(pHead->pRightChild!=NULL)
		{
		lastSearch(pHead->pRightChild);
		}
		printf("%c\n",pHead->value);

	}
}
//if tag==1:rightChild。 if tag==0:leftChild
void reBuild(char* strPre,int preStrLength,char* strMid,int midStrLength,ListNode *node,int tag)
{
	if(preStrLength<1 || midStrLength<1 || node==NULL || strPre==NULL || strMid==NULL || preStrLength!=midStrLength)
	{
		return;
	}
	int i;
	char value=*strPre;
	char *leftNewPreStr=(char *)malloc(preStrLength);
	char *leftNewMidStr=(char *)malloc(midStrLength);
	char *leftPre=leftNewPreStr;
	char *leftMid=leftNewMidStr;


	char *rightNewPreStr=(char *)malloc(preStrLength);
	char *rightNewMidStr=(char *)malloc(midStrLength);
	char *rightPre=rightNewPreStr;
	char *rightMid=rightNewMidStr;

	ListNode *newNode=(ListNode *)malloc(sizeof(ListNode));
	newNode->value=value;
	newNode->pLeftChild=NULL;
	newNode->pRightChild=NULL;
	if(tag)
	{
		node->pRightChild=newNode;
	}else{
		node->pLeftChild=newNode;
	}
	if(preStrLength==1)
	{
		return;
	}
	//在midStr中查找preStr第一个元素，以构建新的左子树mid序列
	while(*strMid!=value){
		*leftNewMidStr=*strMid;
		leftNewMidStr++;
		strMid++;
	}
	strMid++;
	*leftNewMidStr='\0';
	//printf("%s\n",leftMid);
	//剩下的就是右子树的mid序列
	while(*strMid!='\0'){
		*rightNewMidStr=*strMid;
		rightNewMidStr++;
		strMid++;
	}
	*rightNewMidStr='\0';
	//printf("%s\n",rightMid);
	//构建左右子树的pre序列
	strPre++;
	for(i=0;i<strlen(leftMid);i++)
	{
		*leftNewPreStr=*strPre;
		leftNewPreStr++;
		strPre++;
	}
	*leftNewPreStr='\0';
	//printf("%s\n",leftPre);
	for(int i=0;i<=strlen(rightMid);i++)
	{
		*rightNewPreStr=*strPre;
		rightNewPreStr++;
		strPre++;
	}
	//printf("%s\n",rightPre);
	//重建左子树
	reBuild(leftPre,strlen(leftPre),leftMid,strlen(leftMid),newNode,0);
	//重建右子树
	reBuild(rightPre,strlen(rightPre),rightMid,strlen(rightMid),newNode,1);
}

int main()
{
	char *preStr=(char *)malloc(sizeof(100));
	char *midStr=(char *)malloc(sizeof(100));
	ListNode *pHeader=(ListNode *)malloc(sizeof(ListNode));
	pHeader->pLeftChild=NULL;
	pHeader->pRightChild=NULL;
	pHeader->value=-1;
	
	gets(preStr);
	gets(midStr);
	reBuild(preStr,strlen(preStr),midStr,strlen(midStr),pHeader,0);
	lastSearch(pHeader->pLeftChild);
	system("pause");
	return 0;
}