// ********************************************************
// Header file Queuearr.h for the ADT queue.
// Array-based implementation.
// ********************************************************

#ifndef QUEUEARR_H
#define QUEUEARR_H

const int MAX_QUEUE = 30;

typedef type-of-queue-item queueItemType;

class Queue
{
public:
// constructors and destructor:
   Queue();    // default constructor
               // copy constructor and destructor are
               // supplied by the compiler

// queue operations:

//  Determines whether a Queue is empty.
//  Precondition: None.
//  Postcondition: Returns true if the Queue is empty; otherwise returns false.
   int isEmpty();

//  Inserts an item at the back of a Queue.
//  Precondition: NewItem is the item to be inserted.
//  Postcondition: If insertion was successful, NewItem is at the back of 
//  the Queue and insert returns true; otherwise insert returns false.
   int insert(queueItemType NewItem);

//  Deletes the front of a Queue.
//  Precondition: None.
//  Postcondition: If the Queue was not empty, the item that was added to 
//  the Queue earliest is deleted and del returns true. However, if the 
//  Queue was empty, deletion is impossible and del returns false.
   int del();

//  Retrieves and deletes the front of a Queue.
//  Precondition: None.
//  Postcondition: If the Queue was not empty, QueueFront contains the item 
//  that was added to the Queue earliest, the item is deleted, and del returns 
//  true. However, if the Queue was empty, deletion is impossible and del 
//  returns false.
   int del(queueItemType& QueueFront);

//  Retrieves the item at the front of a Queue.
//  Precondition: None.
//  Postcondition: If the Queue was not empty, QueueFront contains the item 
//  that was added to the Queue earliest and getFront returns true. However, 
//  if the Queue was empty, the operation fails, QueueFront is unchanged, and
//  getFront returns false. The Queue is unchanged.
   int getFront(queueItemType& QueueFront);

private:
   queueItemType Items[MAX_QUEUE];
   int           Front;
   int           Back;
   int           Count;
};  // end class
// End of header file.

#endif

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