The document discusses linked lists and C++ code for implementing a linked list. It includes definitions of a Node class to represent individual nodes, with fields for storing data and pointers to other nodes. It also defines a List class for managing the overall linked list, including functions for adding new nodes to the list. Diagrams show how nodes are linked and stored non-contiguously in memory. The code provided implements adding new nodes to the front or end of the linked list by updating pointer references between nodes.

1. Lecture No.03
Data Structures
Dr. Sohail Aslam

2. Linked List

Actual picture in memory:
1051
1052
1053
1063
2
1055
head
1063
1054
current
6
1051
1056
2
6
8
7
1
1057
1058
current
7
1060
1059
1060
1061
head
1
0
1062
1054
1063
8
1064
1057
1065

3. Linked List Operations

add(9): Create a new node in memory to hold ‘9’
Node* newNode = new Node(9);
newNode
9

4. Linked List Operations

add(9): Create a new node in memory to hold ‘9’
Node* newNode = new Node(9);

newNode
Link the new node into the list
head
2
6
8
current
7
2
3
9
newNode
1
1
size=5 6
9

5. C++ Code for Linked List
The Node class
class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };
Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

6. C++ Code for Linked List
The Node class

class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };
Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

7. C++ Code for Linked List
The Node class

class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };
Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

8. C++ Code for Linked List
The Node class

class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };
Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

9. C++ Code for Linked List
The Node class

class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };
Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

10. C++ Code for Linked List
The Node class
class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };

Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

11. C++ Code for Linked List
The Node class
class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };

Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

12. C++ Code for Linked List
The Node class
class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };

Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

13. C++ Code for Linked List
The Node class
class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };

Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

14. C++ Code for Linked List
The Node class
class Node {
public:
int get() { return object; };
void set(int object) { this->object = object; };

Node *getNext() { return nextNode; };
void setNext(Node *nextNode)
{ this->nextNode = nextNode; };
private:
int object;
Node *nextNode;
};

15. C++ Code for Linked List
#include <stdlib.h>
#include "Node.cpp"
class List {
public:
// Constructor
List() {
headNode = new Node();
headNode->setNext(NULL);
currentNode = NULL;
size = 0;
};

16. C++ Code for Linked List

#include <stdlib.h>
#include "Node.cpp"
class List {
public:
// Constructor
List() {
headNode = new Node();
headNode->setNext(NULL);
currentNode = NULL;
size = 0;
};

17. C++ Code for Linked List
#include <stdlib.h>
 #include "Node.cpp"
class List {
public:
// Constructor
List() {
headNode = new Node();
headNode->setNext(NULL);
currentNode = NULL;
size = 0;
};

18. C++ Code for Linked List
#include <stdlib.h>
#include "Node.cpp"

class List {
public:
// Constructor
List() {
headNode = new Node();
headNode->setNext(NULL);
currentNode = NULL;
size = 0;
};

19. C++ Code for Linked List
#include <stdlib.h>
#include "Node.cpp"
class List {
 public:
// Constructor
List() {
headNode = new Node();
headNode->setNext(NULL);
currentNode = NULL;
size = 0;
};

20. C++ Code for Linked List
#include <stdlib.h>
#include "Node.cpp"
class List {
public:
// Constructor
List() {

headNode = new Node();
headNode->setNext(NULL);
currentNode = NULL;
size = 0;
};

21. C++ Code for Linked List
#include <stdlib.h>
#include "Node.cpp"
class List {
public:
// Constructor
List() {

headNode = new Node();
headNode->setNext(NULL);
currentNode = NULL;
size = 0;
};

22. C++ Code for Linked List
#include <stdlib.h>
#include "Node.cpp"
class List {
public:
// Constructor
List() {
headNode = new Node();

headNode->setNext(NULL);
currentNode = NULL;
size = 0;
};

23. C++ Code for Linked List
#include <stdlib.h>
#include "Node.cpp"
class List {
public:
// Constructor
List() {
headNode = new Node();
headNode->setNext(NULL);

currentNode = NULL;
size = 0;
};

24. C++ Code for Linked List
#include <stdlib.h>
#include "Node.cpp"
class List {
public:
// Constructor
List() {
headNode = new Node();
headNode->setNext(NULL);
currentNode = NULL;

size = 0;
};

25. C++ Code for Linked List
void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

26. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

27. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

28. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

29. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

30. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

31. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

32. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

33. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

34. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

35. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

36. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

37. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

38. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

39. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

40. C++ Code for Linked List

void add(int addObject) {
Node* newNode = new Node();
newNode->set(addObject);
if( currentNode != NULL ){
newNode->setNext(currentNode->getNext());
currentNode->setNext( newNode );
lastCurrentNode = currentNode;
currentNode = newNode;
}
else {
newNode->setNext(NULL);
headNode->setNext(newNode);
lastCurrentNode = headNode;
currentNode = newNode;
}
size++;
};

41. Building a Linked List
List list;
headNode
size=0

42. Building a Linked List
List list;
headNode
size=0
currentNode
list.add(2);
headNode
lastcurrentNode
2
size=1

43. Building a Linked List
List list;
headNode
size=0
currentNode
list.add(2);
headNode
2
size=1
lastcurrentNode
currentNode
list.add(6);
headNode
2
6
lastcurrentNode
size=2

44. Building a Linked List
List.add(8); list.add(7); list.add(1);
currentNode
headNode
2
6
8
7
lastcurrentNode
1
size=5

45. C++ Code for Linked List
int get() {
if (currentNode != NULL)
return currentNode->get();
};

46. C++ Code for Linked List
bool next() {
if (currentNode == NULL) return false;
lastCurrentNode = currentNode;
currentNode = currentNode->getNext();
if (currentNode == NULL || size == 0)
return false;
else
return true;
};