Bag.cpp

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

#include "Bag.h"
#include <cstddef>

template<class ItemType>
Bag<ItemType>::Bag() : itemCount(0), maxItems(DEFAULT_BAG_SIZE)
{
}  // end default constructor

template<class ItemType>
int Bag<ItemType>::getCurrentSize() const
{
        return itemCount;
}  // end getCurrentSize

template<class ItemType>
bool Bag<ItemType>::isEmpty() const
{
        return itemCount == 0;
}  // end isEmpty

template<class ItemType>
bool Bag<ItemType>::add(const ItemType& newEntry)
{
        bool hasRoomToAdd = (itemCount < maxItems);
        if (hasRoomToAdd)
        {
                items[itemCount] = newEntry;
                itemCount++;
        }  // end if
    
        return hasRoomToAdd;
}  // end add

template<class ItemType>
bool Bag<ItemType>::remove(const ItemType& anEntry)
{
   int locatedIndex = getIndexOf(anEntry);
        bool canRemoveItem = !isEmpty() && (locatedIndex > -1);
        if (canRemoveItem)
        {
                itemCount--;
                items[locatedIndex] = items[itemCount];
        }  // end if
    
        return canRemoveItem;
}  // end remove

template<class ItemType>
void Bag<ItemType>::clear()
{
        itemCount = 0;
}  // end clear

template<class ItemType>
int Bag<ItemType>::getFrequencyOf(const ItemType& anEntry) const
{
   int frequency = 0;
   int searchIndex = 0;
   while (searchIndex < itemCount)
   {
      if (items[searchIndex] == anEntry)
      {
         frequency++;
      }  // end if
      
      searchIndex++;
   }  // end while
   
   return frequency;
}  // end getFrequencyOf

template<class ItemType>
bool Bag<ItemType>::contains(const ItemType& anEntry) const
{
        return getIndexOf(anEntry) > -1;
}  // end contains

/* ALTERNATE 1
template<class ItemType>
bool Bag<ItemType>::contains(const ItemType& anEntry) const
{
        return getFrequencyOf(anEntry) > 0;
}  // end contains
*/
/* ALTERNATE 2 
template<class ItemType>
bool Bag<ItemType>::contains(const ItemType& anEntry) const
{
   bool found = false;
   for (int i = 0; !found && (i < itemCount); i++)
   {
      if (anEntry == items[i])
      {
         found = true;
      } // end if
   } // end for
   
   return found;
}  // end contains
*/

template<class ItemType>
vector<ItemType> Bag<ItemType>::toVector() const
{
        vector<ItemType> bagContents;
        for (int i = 0; i < itemCount; i++)
                bagContents.push_back(items[i]);
   return bagContents;
}  // end toVector

// private
template<class ItemType>
int Bag<ItemType>::getIndexOf(const ItemType& target) const
{
        bool found = false;
   int result = -1;
   int searchIndex = 0;
   // if the bag is empty, itemCount is zero, so loop is skipped
   while (!found && (searchIndex < itemCount))
   {
      if (items[searchIndex] == target)
      {
         found = true;
         result = searchIndex;
      } 
      else
      {
         searchIndex++;
      }  // end if
   }  // end while
   
   return result;
}  // end getIndexOf