Question

CSCI 2010 Lab11 Link-Lists

Lab 11A Linked-Lists

Preparation

1. Create a Visual Studio C++ Project C2010Lab11A
2. Add the following to the project.

//LinkedList.cpp

#include <cstdlib>
#include "LinkedList.h"
using namespace std;

//---------------------------------------------------
//List Element Members
//---------------------------------------------------
ListElement::ListElement(int d, ListElement * n)
{
   datum=d;
   next=n;
}
int ListElement::getDatum () const
{
   return datum;
}
ListElement const* ListElement::getNext () const
{
   return next;
}

//---------------------------------------------------
//LinkedList Members
//---------------------------------------------------
LinkedList::LinkedList ()
{
   head=NULL;
}

void LinkedList::insertItem(int item)
{
   ListElement *currPtr = head;
   ListElement *prevPtr = NULL;
   ListElement *newNodePtr;      //points to a new node

   while(currPtr != NULL && item > currPtr->datum)
   {
       prevPtr = currPtr;
       currPtr = currPtr->next;
   }

   newNodePtr = new ListElement(item, currPtr);

   if (prevPtr == NULL) // insert at the beginning
       head=newNodePtr;
   else
       prevPtr->next = newNodePtr;
}

void LinkedList::makeList()
{
   int InValue;
   ListElement *currPtr;
   ListElement *newNodePtr;

   cout << "Enter values for a linked list, one per line." << endl
       << "Enter 999 to end the list." << endl;

   cin >> InValue;
   //Adding elements to end so that "next" will be NULL
   newNodePtr=new ListElement(InValue, NULL);
   head=newNodePtr; //assign head to the first Node
   currPtr=head;
   cin >> InValue;

   while ( InValue != 999)
   {
       newNodePtr=new ListElement(InValue, NULL);
       currPtr->next=newNodePtr;     //link the new node to list
       currPtr=newNodePtr;           //move the currPtr so it is at end of list
       cin >> InValue;
   }

}

void LinkedList::appendItem (int item)
{
   //REPLACE THE LINE BELOW WITH YOUR OWN CODE
   cout << "You must implement this function" <<endl;
  
}

void LinkedList::deleteItem (int item)
{
   //REPLACE THE LINE BELOW WITH YOUR OWN CODE
   cout << "You must implement this function" <<endl;
}

void LinkedList::printList ()
{
   //REPLACE THE LINE BELOW WITH YOUR OWN CODE
   cout << "You must implement this function" <<endl;
  
}

// LinkedList.h

#ifndef LINKEDLIST_H
#define LINKEDLIST_H
#include <cstdlib>
#include <iostream>
using namespace std;

class LinkedList; // needed for friend line below

class ListElement
{
private:  
   int datum;
   ListElement* next;  
public:
   ListElement (int, ListElement*);
   int getDatum () const;
   ListElement const* getNext () const;

   friend class LinkedList; // gives LinkedList access to datum and next
};
class LinkedList
{
private:
   ListElement* head;

public:
   LinkedList ();
   void insertItem (int);
   void makeList ();
   void appendItem (int);
   void deleteItem (int);
   void printList ();
};

#endif

//main.cpp

#include<iostream>
#include"LinkedList.h"
#include <string>
using namespace std;

int readInt(string);
int main()
{

   char choice;
   int item;
   LinkedList a;
   cout << "This program demonstrates the linked list. " << endl;
   cout << "Initially, you will be asked to create the list." << endl;
   cout << "You will be later prompted to manipulate the list." <<endl << endl;
   a.makeList();
   choice='b';
   while(choice != 'q')
   {
      cout << "*******************************************************" << endl;
      cout<<"i: Insert (Insert an element and keep the list ordered)\n";
      cout<<"a: Append (Append an element to the end of the list)\n";
      cout<<"d: Delete (Delete a node with the given value)\n";
      cout<<"p: Print (Print the content of the current list)\n";
      cout<<"q: Quit   (Quit the program)\n";
      cout << "*******************************************************" << endl << endl;
      cout<<"\n   Please enter your choice here:";
      cin>>choice;
      switch(choice)
      {
   case 'i':
        item=readInt("to insert:");
        a.insertItem(item);
        break;
   case 'a':
        item=readInt("to append to the end:");
        a.appendItem(item);
        break;

   case 'd':
        item=readInt("to delete:");
        a.deleteItem(item);      
        break;

   case 'p':
        cout << "The content of the current ordered list is: "<<endl;
        a.printList();
        break;
   case 'q':
        break;
   default:
        cout<<"\n Invalid choice. Please try again.\n";
        break;
      }
   }
   cout<<"\n Bye\n";
   return 0;
}  
int readInt(string descr)
{
   int item;
   cout << "\n   Please enter an integer value " << descr;
   cin >> item;
   while (item < 0)
   {
      cout << "\n Please try again:";
      cin >> item;
   }
   return item;
}

The purpose of the program is to demonstrate operations on a simple singly linked list.

Exercise 1

1. Examine the header file and the program carefully.
2. Fill in the right side of the table with the lines of code provided at the top. The purpose here is to help you relate the algorithmic description with the code while viewing the graphical representation of the nodes in a linked list.
3. The diagrams in the following table represent a progression of inserts into an empty linked list.
4. Match the following lines of code with the appropriate illustration on the left.

Use each line only once:

1. currPtr=head;
2. newNodePtr=new ListElement(8,NULL);
3. currPtr->next=newNodePtr;
4. head=newNodePtr;
5. newNodePtr=new ListElement(2,NULL);
6. currPtr=newNodePtr;

Note what changes from one picture to the next. This represents the sequence of operations.

	Fill in answer.
	Fill in answer.
	Fill in answer.
	Fill in answer.
	Fill in answer.
	Fill in answer.

Exercise 2

Now you should be ready to start adding code to that program.

1. First, in LinkedList.cpp, add the code to print out the linked list. The function called LinkedList::printList() is provided in the code; you need to add the implementation.
2. Compile and run this C++ program.
3. Now, add the code to add a single node element to the end of the list. The function called LinkedList::appendItem() is provided in the code; you need to add the implementation.
4. Compile and run this C++ program.
5. Add the code to delete a node from the list. The function called LinkedList::deleteItem() is provided in the code; you need to add the implementation.
6. Compile and run this C++ program.

Try deleting the first, last and middle node. Also try to remove something that is not in the list (an appropriate message should be printed).

When you are happy with the results, script the following test run.

Test Run

1. Make the list: 4 12 16 999
2. Print
3. Insert an 8
4. Print
5. Append a 30
6. Print
7. Delete the 4
8. Print
9. Delete the 30
10. Print
11. Delete the 12
12. Print
13. Try to delete a 2
14. Print

(Paste your .h and .cpp files and a screen capture of the program output here – upload this document to lab11A.)

newNodePtr 704F0 704F0 NULL head 704FO newNodePtr 704F0 704F0 NULL currPtr 704FO head 704F0 newNodePtr 704F0 704F0 NULL currPtr 704F0 head 704F0 newNodePtr 70500 704F0 70500 NULL NULL currPtr 704F0 head 704F0 newNodePtr 70500 704F0 70500 70500 NULL currPtr 70500 newNodePtr 70500 head 704F0 704F0 70500 70500 NULL

Answer 1

Hope this helps you. Thank you.

Exercise-1

According to the diagrams

1. newNodePtr=new ListElement(2,NULL);
2. head=newNodePtr;
3. currPtr=head;
4. newNodePtr=new ListElement(8,NULL);
5. currPtr->next=newNodePtr;
6. currPtr=newNodePtr;

Exercise-2

LinkedList.cpp file

//LinkedList.cpp

#include <cstdlib>
#include "LinkedList.h"
using namespace std;

//---------------------------------------------------
//List Element Members
//---------------------------------------------------
ListElement::ListElement(int d, ListElement * n)
{
datum=d;
next=n;
}
int ListElement::getDatum () const
{
return datum;
}
ListElement const* ListElement::getNext () const
{
return next;
}

//---------------------------------------------------
//LinkedList Members
//---------------------------------------------------
LinkedList::LinkedList ()
{
head=NULL;
}

void LinkedList::insertItem(int item)
{
ListElement *currPtr = head;
ListElement *prevPtr = NULL;
ListElement *newNodePtr; //points to a new node

while(currPtr != NULL && item > currPtr->datum)
{
prevPtr = currPtr;
currPtr = currPtr->next;
}

newNodePtr = new ListElement(item, currPtr);

if (prevPtr == NULL) // insert at the beginning
head=newNodePtr;
else
prevPtr->next = newNodePtr;
}

void LinkedList::makeList()
{
int InValue;
ListElement *currPtr;
ListElement *newNodePtr;

cout << "Enter values for a linked list, one per line." << endl
<< "Enter 999 to end the list." << endl;

cin >> InValue;
//Adding elements to end so that "next" will be NULL
newNodePtr=new ListElement(InValue, NULL);
head=newNodePtr; //assign head to the first Node
currPtr=head;
cin >> InValue;

while ( InValue != 999)
{
newNodePtr=new ListElement(InValue, NULL);
currPtr->next=newNodePtr; //link the new node to list
currPtr=newNodePtr; //move the currPtr so it is at end of list
cin >> InValue;
}

}

void LinkedList::appendItem (int item) {
//REPLACE THE LINE BELOW WITH YOUR OWN CODE
//cout << "You must implement this function" <<endl;

   ListElement *temp = head, *newNodePtr = NULL;
   while(temp->getNext () != NULL) {
       temp = temp->next;
   }

   newNodePtr = new ListElement(item, temp);
   temp -> next = newNodePtr;
   newNodePtr -> next = NULL;

}

void LinkedList::deleteItem (int item) {
//REPLACE THE LINE BELOW WITH YOUR OWN CODE
//cout << "You must implement this function" <<endl;
   bool flag = false;
   if(head->getDatum() == item ) {
       flag = true;
       head = head->next;
   } else {
       ListElement *currPtr = head->next, *prevPtr = head;
       while(currPtr != NULL) {
           if(currPtr->getDatum() == item) {
               flag = true;
               prevPtr -> next = currPtr -> next;
           } else {
               prevPtr = currPtr;
           }
           currPtr = currPtr -> next;
       }
   }
   if(!flag) {
       cout << "No matching data found in the list" << endl;
   }
}

void LinkedList::printList () {
//REPLACE THE LINE BELOW WITH YOUR OWN CODE
//cout << "You must implement this function" <<endl;
   ListElement *temp = head;
while( temp != NULL) {
   cout << temp->getDatum() << " ";
   temp = temp->next;
}
cout << endl;
}

Output:

This program demonstrates the linked list.

Initially, you will be asked to create the list.

You will be later prompted to manipulate the list.

Enter values for a linked list, one per line.

Enter 999 to end the list.

4

12

16

999

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:i

Please enter an integer value to insert:8

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:p

The content of the current ordered list is:

4 8 12 16

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:a

Please enter an integer value to append to the end:30

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:p

The content of the current ordered list is:

4 8 12 16 30

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:d

Please enter an integer value to delete:4

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:p

The content of the current ordered list is:

8 12 16 30

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:d

Please enter an integer value to delete:30

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:p

The content of the current ordered list is:

8 12 16

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:d

Please enter an integer value to delete:12

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:p

The content of the current ordered list is:

8 16

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:d

Please enter an integer value to delete:2

No matching data found in the list

*******************************************************

i: Insert (Insert an element and keep the list ordered)

a: Append (Append an element to the end of the list)

d: Delete (Delete a node with the given value)

p: Print (Print the content of the current list)

q: Quit (Quit the program)

*******************************************************

Please enter your choice here:q

Bye

Thanks. Please do comment if you could not understand anything.