preorder.h

该程序完成对二叉树的非递归的前序遍历

#include<iostream.h>
#include"treenode.h"
#include"stack.h"

template<class T>
void PreorderVisit(TreeNode<T> *t)
{
	Stack<TreeNode<T> *> s;
	TreeNode<T> *p;
	p=t;
	if(p!=NULL)
		s.Push(p);
	while(!s.StackEmpty())
	{
		p=s.Pop();
		cout<<p->data<<" ";
		if(p->Right()!=NULL)
			s.Push(p->Right());
		if(p->Left()!=NULL)
			s.Push(p->Left());
	}
}