nohead_linstack.h

不带头结点的链式堆栈类,1、 定义并实现不带头结点的链式堆栈类

#ifndef NOHEAD_LINSTACK_H
#define NOHEAD_LINSTACK_H

template <class T> class nohead_LinStack;
template <class T>
class StackNode
{
	friend class nohead_LinStack<T>;
private:
	T data;
	StackNode<T> *next;
public:
	StackNode(const T& item,StackNode *ptrNext=NULL)
	{
		data=item;
		next=ptrNext;
	}
	~StackNode(){};
};

template<class T>
class nohead_LinStack
{
private:
	StackNode<T> *head;
	int size;
public:
	nohead_LinStack(void);
	~nohead_LinStack(void);
	void Push(const T& item);
	T Pop(void);
	T GetTop(void)const;
	int NotEmpty(void) const;
};

template <class T>
nohead_LinStack<T>::nohead_LinStack()
{
	head=NULL;
	size=0;
}

template <class T>
nohead_LinStack<T>::~nohead_LinStack(void)
{
	StackNode<T> *p,*q;
	p=head;
	while(p!=NULL)
	{
		q=p;
		p=p->next;
		delete q;
	}
}

template <class T>
int nohead_LinStack<T>::NotEmpty(void) const
{
	if(size!=0) return 1;
	else return 0;
}

template <class T>
void nohead_LinStack<T>::Push(const T &item)
{
	StackNode<T> *newNode=new StackNode<T>(item,head);
	head=newNode;
	size++;
}

template <class T>
T nohead_LinStack<T>::Pop(void)
{
	if(size==0)
	{
		cout<<"The LinStack is empty!"<<endl;
		exit(0);
	}
	StackNode<T> *p=head;
	T data=p->data;
	head=head->next;
	delete p;
	size--;
	return data;
}

template <class T>
T nohead_LinStack<T>::GetTop(void)const
{
	return head->data;
}

#endif