Name of the Staff Member : A.Santhosh Kumar Designation : Lecturer

1. Name of the Staff Member : A.Santhosh Kumar Designation : Lecturer Branch : Computer Engineering Institute : VMR Polytechnic, Rampur, Warangal Semester : III Subject : Data Structures through ‘C’ Subject Code : 9CM305 Topic : Linear Data Structures Duration : 100 Min Sub Topic : Single Linked Circular List Teaching Aids to be used : Power Point Presentation Revised by : Bapuji naik Department of Technical Education Andhra Pradesh 9CM305 .17to18

2. Recap In the previous lessons, you have learnt How to sort elements in a Linked List • Search ? • Search & replace ? • Reverse ? 9CM305 .17to18

3. Objectives On compliotion of this e-lesson, you would be able to know. • What is singly linked circular list ? • How to create singly linked circular list ? • Advantages of singly linked circular list ? 9CM305 .17to18

4. Single Linked List • The collection of node, each node consisting of a data field and a link field to use next node. • Use last node link field contains NULL value because it is not pointing further any other node. 9CM305 .17to18

5. 10 20 30 40 NULL Disadvantages of S.L.L • Once we move from first node last node we cant traverse • i.e. link field is pointing to use next node ( only forward direction) 9CM305 .17to18

6. 10 2000 20 30 4000 3000 40 1000 3000 4000 1000 2000 Singly Linked Circular List • A circular list is a list in which the last node link field is pointing to the first node of list • The singly linked circular list is as followes 9CM305 .17to18

7. Contd… Singly Linked Circular List • In the single linked circular list , the last node link field contains the address of first node • i.e. the last node is pointing to the first node ,to make the linked list circular 9CM305 .17to18

8. Contd… Singly Linked Circular List • In the S.L.C L ,there is no first node • There is no root node , pointing to the first node • We use dummy header pointing to any node • To know that from where to start • Generally dummy header is also pointing to the first node 9CM305 .17to18

9. 1000 Contd… Singly Linked Circular List • Example S.L.C.L uses dummy header Dummy header 1000 2000 4000 3000 3000 4000 1000 2000 9CM305 .17to18

10. Contd… Program to create S.L.C.L Singly Linked Circular List • # include <stdio.h> • # include<conio.h> type def struct linked _list { int info; struct linked _list *link; } NODE ; 9CM305 .17to18

11. Contd… Singly Linked Circular List main() { NODE* first; char s[50]; int i, ele; NODE*insert(NODE* first,int ele); viod display (NODE* first); clrscr(); Printf(“Enter the long integer \n”); Scanf(“%s”,s); printf(“%s”,s); /*since s is a string of charcters the digits you enter will be in charcter form,substract each digit with character’o’ to get the actual integer. For example ‘2’(ascii value50)-’o’(48)=2*/ 9CM305 .17to18

12. Contd… Singly Linked Circular List /*insert all the digits into linked list*/ for(i=0;s[i]!=‘\0’;i++) first=insert(first,s[i]-’0’); printf(“\n the elements of the circular linked list”); display(first); } 9CM305 .17to18

13. Contd… Singly Linked Circular List NODE*insert(NODE*first, int ele) { NODE*new; { new=(NODE*) malloc(size of (NODE); new ->info=ele; if (first->link== first) { first ->link=new; new->link=new; } else { new->link=first->link; first->link=new; } return(first); } 9CM305 .17to18

14. Contd… Singly Linked Circular List • void display(NODE*first) • { • NODE*temp=first->link; • While(temp !=first) • { • printf(“%d”, temp->info) ; • temp=temp->link; • } • } 9CM305 .17to18

15. Summary • In the class, we have understood • disadvantages of S.L.L • Singly linked circular list • Creation of S.L.C.L 9CM305 .17to18

16. Quiz • In the S.L.C.L, the last node link contains 9CM305 .17to18

17. Assignment • Write a program to insert a new node into the S.L.C.L • Write a program to delete a node from the S.L.C.L • Write a program to search an element in S.C,L.L 9CM305 .17to18

18. Questions • 1) Explain the advantages of S.L.C.L • 2) Explain the creation of S.L.C.L 9CM305 .17to18