stack.h

主要显示了图书馆信息系统的查询

template <class T>
struct node
{
	T value;
	node<T> *next;
};

template <class T>
class stack
{
public:
	char Err[35];
	node<T> *First;
	int Count;

	stack(){Count = 0;strcpy(Err,"");First = NULL;}

 	T Pop()
	{
		node<T> *tempNode;
		T tempVal;

		if (First!=NULL)
		{
			tempVal = First->value;
			tempNode = First;
			First = First->next;
			delete(tempNode);
		}
		else return NULL;
		return tempVal;
	}

	T front()
	{
		return First->value;
	}

	T Value()
	{
		if (First!=NULL)
		{
			return First->value;
		}
		return "";
	}



	void Push(T v)
	{
		node<T> *tempNode;
		tempNode = new node<T>;

		tempNode->value = v;
		tempNode->next = First;
		First = tempNode;
	}

	bool Last()
	{
		if (First!=NULL)
			if (First->next==NULL)
				return true;
	return false;
	}

	void Empty()
	{
		T t;
		while (First != NULL)
			t = Pop();
	}

	bool isEmpty()
	{
		if (First != NULL)
			return false;
		return true;
	}	

};


template <class T>
void CopyStack(stack<T>& aStack, stack<T>& bStack)    //Copy b into a
	{
		aStack.Empty();
		stack<T> temp;
		T a;

		while (bStack.isEmpty() == false)
			temp.Push(bStack.Pop());

		while (temp.isEmpty() == false)
		{
			a = temp.Pop();
			bStack.Push(a);
			aStack.Push(a);
		}
	}