C++. Difficulty getting function for call correctly in driver.

I'm having trouble getting the program that gets the position of a given entry in this list. This method will have one parameter of type ItemType that specifies the entry you are searching for. If the entry is found, its position will be returned (an integer in the range 1 through itemCount). If the list contains multiple entries with that same value, return the position of the entry with the smallest position number. If the entry is not found in the list, the method returns zero.

Here is the code I have:

ArrayList.cpp

#include

#include

#include "ArrayList.h" // ADT list operations

using namespace std;

void displayList(ListInterface* listPtr)

{

if (listPtr->isEmpty())

cout << "The list is empty" << endl;

else

{

cout << "The list contains " << endl;

for (int pos = 1; pos <= listPtr->getLength(); pos++)

{

cout << listPtr->getEntry(pos) << " ";

}

cout << endl;

}

}

int main()

{

ListInterface* listPtr = new ArrayList();

cout << "List should be empty" << endl;;

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 0" << endl << endl;

listPtr->insert(1, "two");

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 1" << endl << endl;

listPtr->insert(1, "one");

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 2" << endl << endl;

listPtr->insert(3, "three");

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 3" << endl << endl;

listPtr->insert(3, "two.five");

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 4" << endl << endl;

listPtr->insert(5, "five");

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 5" << endl << endl;

//getPosition

//Call getPosition to display item in list

listPtr->getPosition("one");

displayList(listPtr);

cout << "The position of one in the list is: " << listPtr->getPosition("one") << endl;

cout << "List should be full; next insert should fail" << endl;

if (listPtr->insert(6, "six"))

cout << "Inserted \"six\" at position 6" << endl;

else

cout << "Cannot insert \"six\" at position 6" << endl;

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 5" << endl << endl;

cout << "Remove first entry" << endl;

listPtr->remove(1);

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 4" << endl << endl;

cout << "Remove last entry" << endl;

listPtr->remove(4);

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 3" << endl << endl;

cout << "Remove remaining entries" << endl;

listPtr->remove(1);

listPtr->remove(1);

listPtr->remove(1);

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 0" << endl << endl;

cout << "Try to remove entry from empty list" << endl;

if (listPtr->remove(1))

cout << "Removed an entry" << endl;

else

cout << "Cannot remove entry" << endl;

// test clear

listPtr->insert(1, "one");

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 1" << endl << endl;

listPtr->insert(2, "two");

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 2" << endl << endl;

cout << "Clearing list" << endl;

listPtr->clear();

displayList(listPtr);

cout << "Length : " << listPtr->getLength() << "; should be 0" << endl << endl;

return 0;

} // end main

ListInterface.h

/** Interface for the ADT list

Listing 8-1

@file ListInterface.h */

#ifndef _LIST_INTERFACE

#define _LIST_INTERFACE

template

class ListInterface

{

public:

virtual bool isEmpty() const = 0;

virtual int getLength() const = 0;

virtual bool insert(int newPosition, const ItemType& newEntry) = 0;

virtual bool remove(int position) = 0;

virtual void clear() = 0;

virtual ItemType getEntry(int position) const = 0;

virtual void replace(int position, const ItemType& newEntry) = 0;

virtual int getPosition(const ItemType& anEntry) const = 0;

}; // end ListInterface

#endif

ArrayList.h

/** ADT list: Array-based implementation.

Listing 9-1.

@file ArrayList.h */

#ifndef ARRAY_LIST_

#define ARRAY_LIST_

#include "ListInterface.h"

#include

template

class ArrayList : public ListInterface

{

private:

static const int DEFAULT_CAPACITY = 5; // Small capacity to test for a full list

ItemType items[DEFAULT_CAPACITY+1]; // Array of list items (not using element [0]

int itemCount; // Current count of list items

int maxItems; // Maximum capacity of the list

public:

ArrayList();

// Copy constructor and destructor are supplied by compiler

bool isEmpty() const;

int getLength() const;

bool insert(int newPosition, const ItemType& newEntry);

bool remove(int position);

void clear();

/** @throw PrecondViolatedExcep if position < 1 or

position > getLength(). */

ItemType getEntry(int position) const;

/** @throw PrecondViolatedExcep if position < 1 or

position > getLength(). */

void replace(int position, const ItemType& newEntry);

//getPosition

int getPosition(const ItemType& anEntry) const;

}; // end ArrayList

/** Implementation file for the class ArrayList.

@file ArrayList.cpp */

template

ArrayList::ArrayList() : itemCount(0), maxItems(DEFAULT_CAPACITY)

{

} // end default constructor

template

bool ArrayList::isEmpty() const

{

return itemCount == 0;

} // end isEmpty

template

int ArrayList::getLength() const

{

return itemCount;

} // end getLength

template

bool ArrayList::insert(int newPosition, const ItemType& newEntry)

{

bool ableToInsert = (newPosition >= 1)

&& (newPosition <= itemCount + 1)

&& (itemCount < maxItems);

if (ableToInsert)

{

// Make room for new entry by shifting all entries at

// positions >= newPosition toward the end of the array

// (no shift if newPosition == itemCount + 1)

for (int entryPosition = itemCount; entryPosition >= newPosition; entryPosition--)

items[entryPosition + 1] = items[entryPosition]; // copy the entry right

// Insert new entry

items[newPosition] = newEntry;

itemCount++; // Increase count of entries

} // end if

return ableToInsert;

} // end insert

template

bool ArrayList::remove(int position)

{

bool ableToRemove = (position >= 1) && (position <= itemCount);

if (ableToRemove)

{

// Remove entry by shifting all entries after the one at

// position toward the beginning of the array

// (no shift if position == itemCount)

for (int entryPosition = position; entryPosition < itemCount; entryPosition++)

items[entryPosition] = items[entryPosition + 1]; // copy entry on the right to left

itemCount--; // Decrease count of entries

} // end if

return ableToRemove;

} // end remove

template

void ArrayList::clear()

{

itemCount = 0;

} // end clear

template

ItemType ArrayList::getEntry(int position) const

{

// Enforce precondition

bool ableToGet = (position >= 1) && (position <= itemCount);

assert( ableToGet );

return items[position];

} // end getEntry

template

void ArrayList::replace(int position, const ItemType& newEntry)

{

// Enforce precondition

bool ableToSet = (position >= 1) && (position <= itemCount);

assert (ableToSet);

items[position] = newEntry;

} // end replace

// End of implementation file.

template

int ArrayList::getPosition(const ItemType& anEntry) const

{

//Variable for position

int position = 0;

//Make sure list isn't empty

if(!isEmpty())

{

//Variable for index

int index = 0;

//Locate index

while((position == 0) && (index < itemCount))

{

//Index is at getEntry

if(anEntry == items[index])

{

position = index + 1;

}

}

}

//return position

return position;

}

#endif