Extend the class linkedListType by adding the following function:

Find and delete all occurrences of a given info from the list. Traverse the list only once.) Add these as abstract functions in the class linkedList and provide the definitions of these functions in the class unorderedLinkedList. Also write a program to test this function.

linked list.h

#pragma once

#include

#include

using namespace std;

//Definition of the node

template

struct nodeType

{

Type info;

nodeType *link;

};

//***********************************************************

// Author: D.S. Malik

//

// This class specifies the members to implement an iterator

// to a linked list.

//***********************************************************

template

class linkedListIterator

{

public:

linkedListIterator();

//Default constructor

//Postcondition: current = nullptr;

linkedListIterator(nodeType *ptr);

//Constructor with a parameter.

//Postcondition: current = ptr;

Type operator*();

//Function to overload the dereferencing operator *.

//Postcondition: Returns the info contained in the node.

linkedListIterator operator++();

//Overload the preincrement operator.

//Postcondition: The iterator is advanced to the next node.

bool operator==(const linkedListIterator& right) const;

//Overload the equality operator.

//Postcondition: Returns true if this iterator is equal to

//the iterator specified by right, otherwise it returns

//false.

bool operator!=(const linkedListIterator& right) const;

//Overload the not equal to operator.

//Postcondition: Returns true if this iterator is not equal to

//the iterator specified by right, otherwise it returns

//false.

private:

nodeType *current; //pointer to point to the current

//node in the linked list

};

template

linkedListIterator::linkedListIterator()

{

current = nullptr;

}

template

linkedListIterator::

linkedListIterator(nodeType *ptr)

{

current = ptr;

}

template

Type linkedListIterator::operator*()

{

return current->info;

}

template

linkedListIterator linkedListIterator::operator++()

{

current = current->link;

return *this;

}

template

bool linkedListIterator::operator==

(const linkedListIterator& right) const

{

return (current == right.current);

}

template

bool linkedListIterator::operator!=

(const linkedListIterator& right) const

{return (current != right.current);

}

//***********************************************************

// Author: D.S. Malik

//

// This class specifies the members to implement the basic

// properties of a linked list. This is an abstract class.

// We cannot instantiate an object of this class.

//***********************************************************

template

class linkedListType

{

public:

const linkedListType& operator=(const linkedListType&);

//Overload the assignment operator.

void initializeList();

//Initialize the list to an empty state.

//Postcondition: first = nullptr, last = nullptr, count = 0;

bool isEmptyList() const;

//Function to determine whether the list is empty.

//Postcondition: Returns true if the list is empty, otherwise

//it returns false.

void print() const;

//Function to output the data contained in each node.

//Postcondition: none

int length() const;

//Function to return the number of nodes in the list.

//Postcondition: The value of count is returned.

void destroyList();

//Function to delete all the nodes from the list.

//Postcondition: first = nullptr, last = nullptr, count = 0;

Type front() const;

//Function to return the first element of the list.

//Precondition: The list must exist and must not be empty.

//Postcondition: If the list is empty, the program terminates;

//otherwise, the first element of the list is returned.

Type back() const;

//Function to return the last element of the list.

//Precondition: The list must exist and must not be empty.

//Postcondition: If the list is empty, the program

//terminates; otherwise, the last

//element of the list is returned.

virtual bool search(const Type& searchItem) const = 0;

//Function to determine whether searchItem is in the list.

//Postcondition: Returns true if searchItem is in the list,

//otherwise the value false is returned.

virtual void insertFirst(const Type& newItem) = 0;

//Function to insert newItem at the beginning of the list.

//Postcondition: first points to the new list, newItem is

//inserted at the beginning of the list, last points to

//the last node in the list, and count is incremented by

//1.

virtual void insertLast(const Type& newItem) = 0;

//Function to insert newItem at the end of the list.

//Postcondition: first points to the new list, newItem is

//inserted at the end of the list, last points to the

//last node in the list, and count is incremented by 1.

virtual void deleteNode(const Type& deleteItem) = 0;

//Function to delete deleteItem from the list.

//Postcondition: If found, the node containing deleteItem is

//deleted from the list. first points to the first node,

//last points to the last node of the updated list, and

//count is decremented by 1.

linkedListIterator begin();

//Function to return an iterator at the beginning of the

//linked list.

//Postcondition: Returns an iterator such that current is set

//to first.

linkedListIterator end();

//Function to return an iterator one element past the

//last element of the linked list.

//Postcondition: Returns an iterator such that current is set

//to nullptr.

linkedListType();

//default constructor

//Initializes the list to an empty state.

//Postcondition: first = nullptr, last = nullptr, count = 0;

linkedListType(const linkedListType& otherList);

//copy constructor

~linkedListType();

//destructor

//Deletes all the nodes from the list.

//Postcondition: The list object is destroyed.

protected:

int count; //variable to store the number of list elements

//

nodeType *first; //pointer to the first node of the list

nodeType *last;//pointer to the last node of the list

private:

void copyList(const linkedListType& otherList);

//Function to make a copy of otherList.

//Postcondition: A copy of otherList is created and assigned

//to this list.

};

template

bool linkedListType::isEmptyList() const

{

return (first == nullptr);

}

template

linkedListType::linkedListType() //default constructor

{

first = nullptr;

last = nullptr;

count = 0;

}

template

void linkedListType::destroyList()

{

nodeType *temp;//pointer to deallocate the memory

//occupied by the node

while (first != nullptr)//while there are nodes in the list

{

temp = first;//set temp to the current node

first = first->link; //advance first to the next node

delete temp;//deallocate the memory occupied by temp

}

last = nullptr; //initialize last to nullptr; first has already

//been set to nullptr by the while loop

count = 0;

}

template

void linkedListType::initializeList()

{

destroyList(); //if the list has any nodes, delete them

}

template

void linkedListType::print() const

{

nodeType *current; //pointer to traverse the list

current = first;//set current so that it points to

//the first node

while (current != nullptr) //while more data to print

{

cout << current->info << " ";

current = current->link;

}

}//end print

template

int linkedListType::length() const

{

return count;

}//end length

template

Type linkedListType::front() const

{

assert(first != nullptr);

return first->info; //return the info of the first node

}//end front

template

Type linkedListType::back() const

{

assert(last != nullptr);

return last->info; //return the info of the last node

}//end back

template

linkedListIterator linkedListType::begin()

{

linkedListIterator temp(first);

return temp;

}

template

linkedListIterator linkedListType::end()

{

linkedListIterator temp(nullptr);

return temp;

}

template

void linkedListType::copyList

(const linkedListType& otherList)

{

nodeType *newNode; //pointer to create a node

nodeType *current; //pointer to traverse the list

if (first != nullptr) //if the list is nonempty, make it empty

destroyList();

if (otherList.first == nullptr) //otherList is empty

{

first = nullptr;

last = nullptr;

count = 0;

}

else

{

current = otherList.first; //current points to the

//list to be copied

count = otherList.count;

//copy the first node

first = new nodeType;//create the node

first->info = current->info; //copy the info

first->link = nullptr;//set the link field of

//the node to nullptr

last = first;//make last point to the

//first node

current = current->link;//make current point to

//the next node

//copy the remaining list

while (current != nullptr)

{

newNode = new nodeType;//create a node

newNode->info = current->info; //copy the info

newNode->link = nullptr;//set the link of

//newNode to nullptr

last->link = newNode;//attach newNode after last

last = newNode;//make last point to

//the actual last node

current = current->link;//make current point

//to the next node

}//end while

}//end else

}//end copyList

template

linkedListType::~linkedListType() //destructor

{

destroyList();

}//end destructor

template

linkedListType::linkedListType

(const linkedListType& otherList)

{

first = nullptr;

copyList(otherList);

}//end copy constructor

//overload the assignment operator

template

const linkedListType& linkedListType::operator=

(const linkedListType& otherList)

{

if (this != &otherList) //avoid self-copy

{

copyList(otherList);

}//end else

return *this;

}

unorderedLinkedList.h

#ifndef H_UnorderedLinkedList

#define H_UnorderedLinkedList

//***********************************************************

// Author: D.S. Malik

//

// This class specifies the members to implement the basic

// properties of an unordered linked list. This class is

// derived from the class linkedListType.

//***********************************************************

#include "linkedList.h"

using namespace std;

template

class unorderedLinkedList: public linkedListType

{

using linkedListType::count;

using linkedListType::first;

using linkedListType::last;

public:

bool search(const Type& searchItem) const;

//Function to determine whether searchItem is in the list.

//Postcondition: Returns true if searchItem is in the list,

//otherwise the value false is returned.

void insertFirst(const Type& newItem);

//Function to insert newItem at the beginning of the list.

//Postcondition: first points to the new list, newItem is

//inserted at the beginning of the list, last points to

//the last node, and count is incremented by 1.

//

void insertLast(const Type& newItem);

//Function to insert newItem at the end of the list.

//Postcondition: first points to the new list, newItem is

//inserted at the end of the list, last points to the

//last node, and count is incremented by 1.

void deleteNode(const Type& deleteItem);

//Function to delete deleteItem from the list.

//Postcondition: If found, the node containing deleteItem

//is deleted from the list. first points to the first

//node, last points to the last node of the updated

//list, and count is decremented by 1.

};

template

bool unorderedLinkedList::

search(const Type& searchItem) const

{

nodeType *current; //pointer to traverse the list

bool found = false;

current = first; //set current to point to the first

//node in the list

while (current != NULL && !found)//search the list

if (current->info == searchItem) //searchItem is found

found = true;

else

current = current->link; //make current point to

//the next node

return found;

}//end search

template

void unorderedLinkedList::insertFirst(const Type& newItem)

{

nodeType *newNode; //pointer to create the new node

newNode = new nodeType; //create the new node

newNode->info = newItem;//store the new item in the node

newNode->link = first;//insert newNode before first

first = newNode;//make first point to the

//actual first node

count++;//increment count

if (last == NULL)//if the list was empty, newNode is also

//the last node in the list

last = newNode;

}//end insertFirst

template

void unorderedLinkedList::insertLast(const Type& newItem)

{

nodeType *newNode; //pointer to create the new node

newNode = new nodeType; //create the new node

newNode->info = newItem;//store the new item in the node

newNode->link = NULL;//set the link field of newNode

//to NULL

if (first == NULL)//if the list is empty, newNode is

//both the first and last node

{

first = newNode;

last = newNode;

count++;//increment count

}

else//the list is not empty, insert newNode after last

{

last->link = newNode; //insert newNode after last

last = newNode; //make last point to the actual

//last node in the list

count++;//increment count

}

}//end insertLast

template

void unorderedLinkedList::deleteNode(const Type& deleteItem)

{

nodeType *current; //pointer to traverse the list

nodeType *trailCurrent; //pointer just before current

bool found;

if (first == NULL)//Case 1; the list is empty.

cout << "Cannot delete from an empty list."

<< endl;

else

{

if (first->info == deleteItem) //Case 2

{

current = first;

first = first->link;

count--;

if (first == NULL)//the list has only one node

last = NULL;

delete current;

}

else //search the list for the node with the given info

{

found = false;

trailCurrent = first;//set trailCurrent to point

//to the first node

current = first->link; //set current to point to

//the second node

while (current != NULL && !found)

{

if (current->info != deleteItem)

{

trailCurrent = current;

current = current-> link;

}

else

found = true;

}//end while

if (found) //Case 3; if found, delete the node

{

trailCurrent->link = current->link;

count--;

if (last == current)//node to be deleted

//was the last node

last = trailCurrent; //update the value

//of last

delete current;//delete the node from the list

}

else

cout << "The item to be deleted is not in "

<< "the list." << endl;

}//end else

}//end else

}//end deleteNode

#endif