//  Created by Frank M. Carrano and Tim Henry.
//  Copyright (c) 2013 __Pearson Education__. All rights reserved.

/** Interface for the ADT heap.
    Listing 17-1.
 @file HeapInterface.h */

#ifndef _HEAP_INTERFACE
#define _HEAP_INTERFACE

template<class ItemType>
class HeapInterface
{
public:
   /** Sees whether this heap is empty.
    @return True if the heap is empty, or false if not. */
   virtual bool isEmpty() const = 0;
   
   /** Gets the number of nodes in this heap.
    @return The number of nodes in the heap. */
   virtual int getNumberOfNodes() const = 0;
   
   /** Gets the height of this heap.
    @return The height of the heap. */
   virtual int getHeight() const = 0;
   
   /** Gets the data that is in the root (top) of this heap.
    For a maxheap, the data is the largest value in the heap;
    for a minheap, the data is the smallest value in the heap.
    @pre The heap is not empty.
    @post The root’s data has been returned, and the heap is unchanged.
    @return The data in the root of the heap. */
   virtual ItemType peekTop() const = 0;
   
   /** Adds a new node containing the given data to this heap.
    @param newData The data for the new node.
    @post The heap contains a new node.
    @return True if the addition is successful, or false if not. */
   virtual bool add(const ItemType& newData) = 0;
   
   /** Removes the root node from this heap.
    @return True if the removal is successful, or false if not. */
   virtual bool remove() = 0;
   
   /** Removes all nodes from this heap. */
   virtual void clear() = 0;
}; // end HeapInterface
#endif