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;
};