非递归二叉树C++

#include<iostream>
#include<queue>				//导入自带队列库
#include<stack>				//导入自带栈库
using namespace std;

template<class T>
struct BiNode
{
	T data;
	BiNode<T> *lchild,*rchild;
	int flag;									//用于后序遍历
};


template<class T>
class BiTree
{
public:
	BiTree(queue<T> quer)
	{
		que = quer;
		root = creat(root);
	}
	~BiTree(){release(root);}
	void preOrder(){preOrder(root);}			//从根节点开始遍历
	void inOrder(){inOrder(root);}
	void behOrder(){behOrder(root);}
	void initArray(char *a);
	queue<T> que; 
	stack<BiNode<T>*> sta;								//初始化一个放入对象的栈
private:
	BiNode<T> *root;
	BiNode<T> *creat(BiNode<T> *bt);
	void release(BiNode<T> *bt);
	void preOrder(BiNode<T> *bt);
	void inOrder(BiNode<T> *bt);
	void behOrder(BiNode<T> *bt);
};

template<class T>
BiNode<T>* BiTree<T>::creat(BiNode<T> *bt)				//创建二叉树
{
	char ch = que.front();			//获取队头元素
	que.pop();						//弹出队头
	if(ch=='#')bt = NULL;
	else{
		bt = new BiNode<T>;
		bt->data = ch;
		bt->lchild = creat(bt->lchild);
		bt->rchild = creat(bt->rchild);
	}
	return bt;
}

template<class T>
void BiTree<T>::preOrder(BiNode<T> *bt)					//先序遍历
{
	while(bt!=NULL || sta.empty()!=1)
	{
		while(bt!=NULL)
		{
			cout<<bt->data<<" ";
			sta.push(bt);
			bt = bt->lchild;
		}
		if(sta.empty()!=1)								//栈非空
		{
			bt = sta.top();								//返回栈顶元素
			sta.pop();
			bt = bt->rchild;
		}
	}
}

template<class T>
void BiTree<T>::inOrder(BiNode<T> *bt)					//中序遍历
{
	while(bt!=NULL || sta.empty()!=1)
	{
		while(bt!=NULL)
		{
			sta.push(bt);
			bt = bt->lchild;
		}
		if(sta.empty()!=1)								//栈非空
		{
			bt = sta.top();								//返回栈顶元素
			cout<<bt->data<<" ";						//后输出元素
			sta.pop();
			bt = bt->rchild;
		}
	}
}

template<class T>
void BiTree<T>::behOrder(BiNode<T> *bt)					//后序遍历
{
	BiNode<T> *temp = new BiNode<T>;
	while(bt!=NULL || sta.empty()!=1)
	{
		while(bt!=NULL)							//先遍历左子树
		{
			bt->flag = 1;
			sta.push(bt);
			bt = bt->lchild;
		}
		while(sta.empty()!=1)					//不对bt做任何操作
		{
			temp = sta.top();
			if(temp->flag==2)
			{
				sta.pop();
				cout<<temp->data<<" ";
			}
			else
			{
				break;
			}
		}
		if(sta.empty()!=1)						//栈顶改为2，遍历右子数（1表示左子数遍历完毕，2表示右子数遍历完毕）
		{
			bt = sta.top();						//获取栈顶元素
			bt->flag = 2;
			bt = bt->rchild;
		}
	}
}

template<class T>
void BiTree<T>::release(BiNode<T> *bt)					//释放节点
{
	if(bt!=NULL){
		release(bt->lchild);
		release(bt->rchild);
		delete bt;
	}
}



void main()
{
	char a[] = "ABD#G###CE##F##";			//必须是扩展二叉树(每个节点必须有两个度)
	queue<char> que;					//初始化队列 ，先进先出，出队
	for(int i=0;i<sizeof(a)-1;i++)
	{
		que.push(a[i]);
	}

	BiTree<char> myTree(que);

	cout<<"先序遍历:"<<endl;
	myTree.preOrder();									//先序遍历

	cout<<endl<<"中序遍历:"<<endl;
	myTree.inOrder();									//中序遍历

	cout<<endl<<"后序遍历:"<<endl;
	myTree.behOrder();									//后序遍历
	cout<<endl;
}