标签:
题目:从上到下安层打印二叉树,同一层的结点按从左到右的顺序打印,每一层打印一行。例如,图(1)中二叉树以及打印结果为:
#include <iostream>
#include <queue>
using namespace std;
struct BinaryTree
{
	int data;
	BinaryTree *pLeft;
	BinaryTree *pRight;
};
BinaryTree *pRoot1=NULL;
queue<BinaryTree *> node;
void CreateTree(BinaryTree *&root)
{
	int data;
	cin>>data;
	if(0==data)
		root=NULL;
	else
	{
		root=new BinaryTree;
		root->data=data;
		CreateTree(root->pLeft);
		CreateTree(root->pRight);
	}
}
void PrintTree(BinaryTree *root)
{
	if(NULL==root)
		return;
	node.push(root);
	int nextlevel=0;//下一层的结点数;
	int tobePrinted=1;//当前还有几个结点;
	while(!node.empty())
	{
		BinaryTree *pNode=node.front();
		cout<<pNode->data<<" ";
		if(pNode->pLeft!=NULL)
		{
			node.push(pNode->pLeft);
			nextlevel++;
		}
		if(pNode->pRight!=NULL)
		{
			node.push(pNode->pRight);
			nextlevel++;
		}
		node.pop();//入队列的速度比出队列的要快;
		tobePrinted--;
		if(tobePrinted==0)
		{
			cout<<endl;//一行打印完了,所以换行;
			tobePrinted=nextlevel;
			nextlevel=0;
		}
	}
}
int main()
{
	CreateTree(pRoot1);
	cout<<"之字形打印如下:"<<endl;
	PrintTree(pRoot1);
	cout<<endl;
	system("pause");
	return 0;
}
运行结果如下:
标签:
原文地址:http://blog.csdn.net/gogokongyin/article/details/51778388