queue.h

包括图、二叉树、链表

#include "Node.h"
enum Error_code {success,overflow,underflow};
const int maxqueue = 10; //  small value for testing
typedef Node_entry Queue_entry;
class Queue {
public:
	// standard Queue methods
	Queue();
	bool empty() const;
	Error_code append(const Queue_entry &item);
	Error_code serve();
	Error_code retrieve(Queue_entry &item) const;
	// safety features for linked structures
	~Queue();
	Queue(const Queue &original);
	void operator =(const Queue &original);
protected:
	Node *front, *rear;
};