1. LINKED LIST

2. Linked Lists
A Linked List is a linear collection of data elements, called nodes pointing to the next nodes by means of pointers

3. NEED FOR LINKED LIST
Linked List overcome the drawbacks of arrays as in linked list number of elements need not be predetermined, more memory can be allocated or released during the processing as when required ,making insertions and deletions much easier and simpler

4. TYPES OF LINKED LIST Linked list are of two types:-
Singly linked lists: It contains node with single pointer pointing to the next node in sequence
Doubly linked list: it contains two pointers, one pointing to previous node and other pointing to the next node in sequence

5. Singly linked list LIST START 10 20 30 40 Next point of second node
Pointer storing the address
Of first node
Info part

6. Basic operations on singly linked list
Searching
Insertion
Deletion
Traversal
Reversal
Splitting
Concatenation
but we will discuss only insertion, deletion and traversal only

7. Singly linked list Insertion in the beginning of the list 10 20 30 40
New link 5
Represents the status before
insertion
Insertion in the beginning of the list

8. Insertion In the beginning of a list Algorithm ptr=START
NEWPTR=new node
If NEWPTR=NULL
Print “no space available ! Aborting !!”
Else {
NEWPTR  INFO=ITEM
NEWPTR  LINK=NULL
If START=NULL then
START=NEWPTR
Save=START
NEWPTR - LINK=save }
END

9. Singly linked list Insertion in the end of the list Previously null 1020 30 40
New link 50
Insertion in the end of the list

10. Insertion in the end of list
Declare pointers START,PTR,NEWPTR,REAR
PTR=START
NEWPTR=new node
If NEWPTR=NULL
Print ”no space available !aborting!!!”
Exit
ELSE
{ NEWPTR LINK=NULL}
If START=NULL THEN
{ START=NEWPTR
REAR=NEWPTR }
REAR  LINK = NEWPTR
END

11. DELETION Deletion of item from a linked list involves
Search for item in the list
If available, make its previous node point to its next node

12. Singly linked list Deletion of a item from the linked list New link 1020 30 40 50
ITEM 60
Represents Old links
Deletion of a item from the linked list

13. Deletion from the beginning of list
Declare pointers START,ptr
If START=NULL then
print “underflow”
else {
Ptr=START
START = ptr  LINK
Delete ptr }
end

14. Traversal
It means processing of all the nodes of the list one by one. the following algorithm prints all the elements of it
ptr=start
Repeat steps (iii) and (iv) until ptr=NULL
Print ptr  INFO
Ptr = ptr  LINK
end

15. THANK YOU