数据结构实现－队列－循环队列－用链表实现[anank].cpp

数据结构中队列的应用

/*********************************************************************************
** Program Name : implementation of circle queue ( by chain )
** Author  Name : Lu Jian Hua
** Time         : 2007-5-23
**********************************************************************************/

#include <iostream>
using namespace std ;

class Node
{
public:
	Node() : data(0), next(NULL) {}
	int data ;
	Node *next ;
} ;

class Queue									// class of Queue
{
public:
	Queue() ;
	Node*  GetValue() const ;					// get the current value of Queue
	void  Delete() ;							// out_Queue
	void Append(int value) ;				// In__Queue
	void Cleaner() ;						// cleaner of Queue			
	bool IsEmpty() const ;					// is empty ?
	bool IsFull()  const ;					// is full ?
private:
	Node* front ;								// front
	Node* rear  ;								// rear
} ;

Queue::Queue() : front(NULL), rear(NULL) {}

Node* Queue::GetValue() const
{
	if ( IsEmpty() )
	{
		cout << "The queue is empty!" << endl << endl ;
		return 0 ;
	}
	
	return front ;
}

void Queue::Append(int value)
{
	Node *temp = new Node() ;
	temp->data = value ;

	if (front == NULL)				// no element in the queue
	{
		front = temp ;
		rear  = front ;
		rear->next = NULL ;
	}
	else
	{
		rear->next = temp ;
		rear = temp ;
		rear->next = NULL ;
	}
}

void Queue::Delete()
{
	if ( IsEmpty() )
	{
		cout << "The queue is empty!" << endl << endl ;
		return ;
	}

	Node *record = front ;
	
	front = front->next ;
	delete record ;
	cout << "The specific node has beend deleted!" << endl << endl ;
}

void Queue::Cleaner()
{
	while (front)
	{
		Node *record = front->next ;
		delete front ;
		front = record ;
	}
	cout << "Cleaner has done it's work...\n\n" ;
}

bool Queue::IsEmpty() const						
{
	return (front == NULL) ;
}

bool Queue::IsFull()  const
{
	return ( false ) ;			// never full until no enough memory accommodated
}

Queue* CreateQueue()
{
	Queue *ptr = new Queue() ;
	return ptr ;
}


int main()
{

	Queue *ptr = CreateQueue() ;

	while (true)
	{
		cout << "-------------------------------------------------" << endl
			 << "1> Append" << endl
			 << "2> Delete" << endl
			 << "3> Get the value" << endl
			 << "4> Is empty ? " << endl
			 << "5> Is Full?     " << endl
			 << "6> Release the queue?  " ;
		char c = 0 ;
		cin  >> c ;
		cout << endl ;

		int value = 0 ;

		switch (c)
		{
		case '1':
			cout << "Enter the value : " ;
			cin  >> value ;
			ptr->Append(value) ;
			break ;
		case '2':
			ptr->Delete() ;
			break ;
		case '3':
			cout << "The value getted : " ;
			if ( ptr->IsEmpty() )
				cout << "NULL" << endl << endl ;
			else
				cout << (ptr->GetValue())->data  << endl << endl ;
			break ;
		case '4':
			cout << "Is empty ? " << ( ptr->IsEmpty() ? "Yes" : "No" ) << endl << endl ;
			break ;
		case '5':
			cout << "Is full ? " <<  ( ptr->IsFull()  ? "Yes" : "No" ) << endl << endl ;
			break ;
		case '6':
			ptr->Cleaner() ;
			break ;
		default:
			break ;
		}
	}

	return 0 ;
}

/********************************************************************************
*
* Notice : This Program Can Be Launched In VC6.0 Environment
*
********************************************************************************/