1. Data Structures (CS301) Linked List and its implementation
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2. Objective
Objective of this presentation is to teach you the concept and implementation of list data structure by using linked list
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3. What is a linked list? It is a dynamic data structure.
Linked list consist of series of nodes
Chain the nodes together to form a linked list
Structure of each node is like the one given below
Data
Next
1000
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4. Linked list Analogy to a train
Insert a node with value ‘2’ in existing list

5. Graphical Representation of Linked List
Picture of our list (2, 6, 8, 7, 1) stored as a linked list:
8000
1000 2
3000 6
5000 8
2000 7
6000 1
headNode
lastcurrentNode
currentNode
Size = 5
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6. C++ Code for linked list
We need two classes to implement linked list:
Node Class
List class
In addition to linked list class and node class, we also need a function main() from where execution of our program will start.
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7. Example
Create a list of students using linked list data structure.

8. Defining a Node class (Student)
class Student { char* Rollno; Student *NextStudent; public: Student() // Constructor Rollno=""; NextStudent=NULL; } void Set_RollNo(char* rno) //Setter function to set data member Rollno Rollno = rno; char* Get_RollNo() //Getter function to get value of Rollno return Rollno;

9. Node class (Student) Con’t
void SetNextStudent(Student *NS) //Setter function to set NextStudent { NextStudent = NS; } Student* getNextStudent() //Getter function to get value of NextStudent return NextStudent; };

10. StudentList class class StudentList { private:
Student *HeadStudent,*CurrentStudent;
public:
StudentList::StudentList() // Constructor
HeadStudent = new Student();
HeadStudent->SetNextStudent(NULL);
CurrentStudent = NULL; }
HeadStudent
8000
8000
CurrentStudent
NULL

11. Add function
void Add_Student(char* rno) // Function to add students in list {
Student *NewStudent = new Student();
NewStudent->Set_RollNo(rno);
NewStudent->SetNextStudent(NULL);
if(CurrentStudent == NULL)
HeadStudent = NewStudent;
CurrentStudent = NewStudent; }
else
CurrentStudent->SetNextStudent(NewStudent);
CurrentStudent= NewStudent;
cout<<CurrentStudent->Get_RollNo();

12. Main() function main() // Main() function { StudentList S;
S.Add_Student("MC ");
cout<<endl;
S.Add_Student("MC ");
S.Add_Student("MC ");
system("pause"); }

13. Output

14. Your Tasks
Task 1:
Remove the following line from end of Add() function.
cout<<CurrentStudent->Get_RollNo();
Task 2:
Add traverse (display) function to display roll number of students.
Task3:
Add more attributes (name, GPA, semester etc) in student class and make changes in your code accordingly.