从上到下遍历二叉树

代码：

/*
从上到下遍历二叉树
by Rowandjj
2014/8/1
*/
#include<iostream>
using namespace std;
typedef struct _BNODE_
{
	int data;
	struct _BNODE_ *lChild;
	struct _BNODE_ *rChild;
}BNode,*pTree,*pNode;
typedef struct _QUEUENODE_
{
	pNode data;
	struct _QUEUENODE_ *next;
}QNode,*pQNode;
typedef struct _QUEUE_
{
	pQNode pHead;
	pQNode pTail;
}Queue,*pQueue;
void InitQueue(pQueue pQ)
{
	pQ->pHead = pQ->pTail = (pQNode)malloc(sizeof(QNode));
	if(pQ->pHead == NULL)
	{
		exit(-1);
	}
	pQ->pHead->next = NULL;
}
void Enqueue(pQueue pQ,pNode data)
{
	if(pQ == NULL || data == NULL)
	{
		return;
	}
	pQNode pNew = (pQNode)malloc(sizeof(QNode));
	if(!pNew)
	{
		exit(-1);
	}
	pNew->data = data;
	pNew->next = NULL;
	pQ->pTail->next = pNew;
	pQ->pTail = pNew;
}
pNode Dequeue(pQueue pQ)
{
	if(pQ == NULL)
	{
		return NULL;
	}
	pQNode pDel = pQ->pHead->next;
	if(pDel == NULL)
	{
		return NULL;
	}	
	pNode data = pDel->data;
	if(pDel == pQ->pTail)
	{
		pQ->pTail = pQ->pHead;
	}
	pQ->pHead->next = pDel->next;
	free(pDel);
	return data;
}
void Destroy(pQueue pQ)
{
	if(pQ == NULL)
	{
		return;
	}
	pNode pTemp;
	while((pTemp = Dequeue(pQ)) != NULL)
	{	
		free(pTemp);
	}
	free(pQ->pHead);
}
//层次遍历
void LevelTraverse(pTree pT)
{
	if(pT == NULL)
	{
		return;
	}
	Queue q;
	InitQueue(&q);
	Enqueue(&q,pT);
	pNode pTemp;
	while((pTemp = Dequeue(&q)) != NULL)
	{
		cout<<pTemp->data<<" ";
		if(pTemp->lChild)
		{
			Enqueue(&q,pTemp->lChild);
		}
		if(pTemp->rChild)
		{
			Enqueue(&q,pTemp->rChild);
		}
	}
	Destroy(&q);
}
void Create(pTree *pT)
{
	int data;
	cin>>data;
	if(data != -1)
	{
		*pT = (pTree)malloc(sizeof(BNode));
		if(*pT == NULL)
		{
			exit(-1);
		}
		(*pT)->lChild = NULL;
		(*pT)->rChild = NULL;
		(*pT)->data = data;
		Create(&(*pT)->lChild);
		Create(&(*pT)->rChild);
	}
}
int main()
{
	pTree pT= NULL;
	Create(&pT);
	LevelTraverse(pT);
	return 0;
}

从上到下遍历二叉树,布布扣,bubuko.com

从上到下遍历二叉树

原文：http://blog.csdn.net/chdjj/article/details/38341289