Dividing a linked list into two sublists of almost equal siz

Dividing a linked list into two sublists of almost equal sizes

a. Add the operation divideMid to the class linkedListType as follows:

Consider the following statements:

unorderedLinkedList<int> myList;
unorderedLinkedList<int> subList;

Suppose myList points to the list with elements 34 65 27 89 12 (in this order). The statement: myList.divideMid(subList); divides myList into two sublists: myList points to the list with the elements 34 65 27,
and subList points to the sublist with the elements 89 12.

b. Write the definition of the function template to implement the operation divideMid. Also, write a program to test your function. The header files linkedList.h and unorderedLinkedList.h are supplied. Your test program should produce output similar to this:

Turn in:
linkedList.h with modifications
Your test program.

(C++)

Required code is below:

#ifndef H_UnorderedLinkedList
#define H_UnorderedLinkedList

#include \"linkedList.h\"

using namespace std;

template <class Type>
class unorderedLinkedList: public linkedListType<Type>
{
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 in the
// list, 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 in the
// list, 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 <class Type>
bool unorderedLinkedList<Type>::
search(const Type& searchItem) const
{
nodeType<Type> *current; //pointer to traverse the list
bool found = false;

current = this->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 <class Type>
void unorderedLinkedList<Type>::insertFirst(const Type& newItem)
{
nodeType<Type> *newNode; //pointer to create the new node

newNode = new nodeType<Type>; //create the new node

newNode->info = newItem; //store the new item in the node
newNode->link = this->first; //insert newNode before first
this->first = newNode; //make first point to the
//actual first node
this->count++; //increment count

if (this->last == NULL) //if the list was empty, newNode is also
//the last node in the list
this->last = newNode;
}//end insertFirst

template <class Type>
void unorderedLinkedList<Type>::insertLast(const Type& newItem)
{
nodeType<Type> *newNode; //pointer to create the new node

newNode = new nodeType<Type>; //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 (this->first == NULL) //if the list is empty, newNode is
//both the first and last node
{
this->first = newNode;
this->last = newNode;
this->count++; //increment count
}
else //the list is not empty, insert newNode after last
{
this->last->link = newNode; //insert newNode after last
this->last = newNode; //make last point to the actual
//last node in the list
this->count++; //increment count
}
}//end insertLast

template <class Type>
void unorderedLinkedList<Type>::deleteNode(const Type& deleteItem)
{
nodeType<Type> *current; //pointer to traverse the list
nodeType<Type> *trailCurrent; //pointer just before current
bool found;

if (this->first == NULL) //Case 1; the list is empty.
cout << \"Cannot delete from an empty list.\"
<< endl;
else
{
if (this->first->info == deleteItem) //Case 2
{
current = this->first;
this->first = this->first->link;
this->count--;
if (this->first == NULL) //the list has only one node
this->last = NULL;
delete current;
}
else //search the list for the node with the given info
{
found = false;
trailCurrent = this->first; //set trailCurrent to point
//to the first node
current = this->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;
this->count--;

if (this->last == current) //node to be deleted
//was the last node
this->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

#ifndef H_LinkedListType
#define H_LinkedListType

#include <iostream>
#include <cassert>

using namespace std;

//Definition of the node

template <class Type>
struct nodeType
{
Type info;
nodeType<Type> *link;
};

template <class Type>
class linkedListIterator
{
public:
linkedListIterator();
//Default constructor
//Postcondition: current = NULL;

linkedListIterator(nodeType<Type> *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<Type> operator++();
//Overload the pre-increment operator.
//Postcondition: The iterator is advanced to the next
// node.

bool operator==(const linkedListIterator<Type>& right) const;
//Overload the equality operator.
//Postcondition: Returns true if this iterator is equal to
// the iterator specified by right,
// otherwise it returns the value false.

bool operator!=(const linkedListIterator<Type>& 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 the value
// false.

private:
nodeType<Type> *current; //pointer to point to the current
//node in the linked list
};

template <class Type>
linkedListIterator<Type>::linkedListIterator()
{
current = NULL;
}

template <class Type>
linkedListIterator<Type>::
linkedListIterator(nodeType<Type> *ptr)
{
current = ptr;
}

template <class Type>
Type linkedListIterator<Type>::operator*()
{
return current->info;
}

template <class Type>
linkedListIterator<Type> linkedListIterator<Type>::operator++()
{
current = current->link;

return *this;
}

template <class Type>
bool linkedListIterator<Type>::operator==
(const linkedListIterator<Type>& right) const
{
return (current == right.current);
}

template <class Type>
bool linkedListIterator<Type>::operator!=
(const linkedListIterator<Type>& right) const
{ return (current != right.current);
}

//***************** class linkedListType ****************

template <class Type>
class linkedListType
{
public:
const linkedListType<Type>& operator=
(const linkedListType<Type>&);
//Overload the assignment operator.

void initializeList();
//Initialize the list to an empty state.
//Postcondition: first = NULL, last = NULL, 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 = NULL, last = NULL, 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<Type> begin();
//Function to return an iterator at the begining of the
//linked list.
//Postcondition: Returns an iterator such that current is
// set to first.

linkedListIterator<Type> 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 NULL.

linkedListType();
//default constructor
//Initializes the list to an empty state.
//Postcondition: first = NULL, last = NULL, count = 0;

linkedListType(const linkedListType<Type>& 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
//elements in the list
nodeType<Type> *first; //pointer to the first node of the list
nodeType<Type> *last; //pointer to the last node of the list

private:
void copyList(const linkedListType<Type>& otherList);
//Function to make a copy of otherList.
//Postcondition: A copy of otherList is created and
// assigned to this list.
};

template <class Type>
bool linkedListType<Type>::isEmptyList() const
{
return(first == NULL);
}

template <class Type>
linkedListType<Type>::linkedListType() //default constructor
{
first = NULL;
last = NULL;
count = 0;
}

template <class Type>
void linkedListType<Type>::destroyList()
{
nodeType<Type> *temp; //pointer to deallocate the memory
//occupied by the node
while (first != NULL) //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 = NULL; //initialize last to NULL; first has already
//been set to NULL by the while loop
count = 0;
}

template <class Type>
void linkedListType<Type>::initializeList()
{
destroyList(); //if the list has any nodes, delete them
}

template <class Type>
void linkedListType<Type>::print() const
{
nodeType<Type> *current; //pointer to traverse the list

current = first; //set current so that it points to
//the first node
while (current != NULL) //while more data to print
{
cout << current->info << \" \";
current = current->link;
}
}//end print

template <class Type>
int linkedListType<Type>::length() const
{
return count;
} //end length

template <class Type>
Type linkedListType<Type>::front() const
{
assert(first != NULL);

return first->info; //return the info of the first node
}//end front

template <class Type>
Type linkedListType<Type>::back() const
{
assert(last != NULL);

return last->info; //return the info of the last node
}//end back

template <class Type>
linkedListIterator<Type> linkedListType<Type>::begin()
{
linkedListIterator<Type> temp(first);

return temp;
}

template <class Type>
linkedListIterator<Type> linkedListType<Type>::end()
{
linkedListIterator<Type> temp(NULL);

return temp;
}

template <class Type>
void linkedListType<Type>::copyList
(const linkedListType<Type>& otherList)
{
nodeType<Type> *newNode; //pointer to create a node
nodeType<Type> *current; //pointer to traverse the list

if (first != NULL) //if the list is nonempty, make it empty
destroyList();

if (otherList.first == NULL) //otherList is empty
{
first = NULL;
last = NULL;
count = 0;
}
else
{
current = otherList.first; //current points to the
//list to be copied
count = otherList.count;

//copy the first node
first = new nodeType<Type>; //create the node

first->info = current->info; //copy the info
first->link = NULL; //set the link field of
//the node to NULL
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 != NULL)
{
newNode = new nodeType<Type>; //create a node
newNode->info = current->info; //copy the info
newNode->link = NULL; //set the link of
//newNode to NULL
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 <class Type>
linkedListType<Type>::~linkedListType() //destructor
{
destroyList();
}//end destructor

template <class Type>
linkedListType<Type>::linkedListType
(const linkedListType<Type>& otherList)
{
first = NULL;
copyList(otherList);
}//end copy constructor

//overload the assignment operator
template <class Type>
const linkedListType<Type>& linkedListType<Type>::operator=
(const linkedListType<Type>& otherList)
{
if (this != &otherList) //avoid self-copy
{
copyList(otherList);
}//end else

return *this;
}

#endif

template <class Type>

void linkedListType<Type>DivideMid(linkedListType<Type> &sublist)

{

int myListItems, subListItems;

if ((count%2)!=0) myListItems = (count/2 + 1);

else myListItems = (count/2);

subListItems = (count - myListItems);

nodeType<Type> *current;

current = first;

sublist.last = last;