This document contains a presentation on linked lists. It includes: 1. An introduction to linked lists describing their representation using linked allocation and algorithms for inserting and deleting nodes. 2. Algorithms for inserting a node at the first, last, and ordered positions in a single linked list, as well as deleting a node and copying a linked list. 3. A section on linear linked list multiple choice questions.

1. Dgroup@mca.com ************
Presentation
ON
BY
D Group

2. Member of D group
Privanka Dabhai
Insert at first in single linked list
Praful Aparnathi
Insert at Last in single linked list
Arpan Shah
Insert at Order in single linked list
Narendra Chauhan
Delete in single linked list
Ram Sanjay
Copy in single linked list
Rushabh Bhavsar
MCQ
Bhavisha Purohit

3. Index Of Linear Linked List
INDEX
1.Introduction
2.Algorithms
3.MCQ

4. Introduction Of Linked List
Introduction Of Linked List
This subsection describes in detail the
representation of linear lists using linked
allocation. Algorithms such as the insertion of
nodes and the deletion of nodes from a linked
linear list are given.
The programming aspects of linked allocation
are discussed both from the simulation point of
view, using arrays, and from the programmer
defined data type facility available in pascal.

5. Introduction Of Linked List
Introduction Of Linked List
The first approach is the one which is usually taken in
programming linked represented structures in languages
that do not have pointer or link facilities, such as
FORTRAN,ALGOL 60 and BASIC, while the second
approach is used in languages that do have pointer
facilities, such as Pascal, PL/ISNOBOL,ALGOL 68 and
ALGOL W.

6. Introduction Of Linked List
Introduction Of Linked List
info Link

7. Introduction Of Linked List
Introduction Of Linked List
The pointer variable AVAIL contains the address of the top
node in the stack. The address of the next available node
is to be stored in the variable NEW.
If a node is available then the new top most element of the
stack is denoted by LINK(AVAIL). The fields of the node
corresponding to the pointer value of NEW can now be
filled in and the field LINK(NEW) is set to a value which
designates the successor node of this new node.

8. Introduction Of Linked List
A similar procedure can be formulated for the
return of a discarded node to the availability
stack. If the address of this discarded node is
given by the variable FREE, then the link field
of this node is set to the present value of
AVAIL and the value of FREE becomes the
new value of AVAIL.
We can now formulate an algorithm which
inserts a node into a linked linear list in a
stack like manner.

9. Algorithms of Linked List
Algorithms
→ Insert at first in single linked list
→ Insert at Last in single linked list
→ Insert at Order in single linked list
→ Delete in single linked list
→ Copy in single linked list

10. Insert at first in single linked
Insert at first in single linked list
INSERT(X,FIRST)
Where X is a new element and FIRST, a pointer to the first element
of a linked linear list whose typical node contains INFO and LINK fields
as previously described, this function insert X. AVAIL is a pointer to the
top element of the availability stack; NEW is a temporary pointer
variable. It is required that X precede the node whose address is given
to the FIRST.

11. INSERT(X,FIRST) linked list
Insert at first in single linked list
Step 1: [Underflow?]
if AVAIL= NULL
Then write (“Availability stack underflow”)
return (FIRST)
Step 2: [Obtain address of next free node]
NEW ←AVAIL
Step 3: [Remove free node from availability
node]
AVAIL ← Step 4: [Initialize fields node from availability
LINK(AVAIL)
stack]
INFO(NEW) ← X
LINK(NEW) ← FIRST
Step 5: [Return address of new node]
Return(NEW)

12. INSERT_LAST(X,FIRST)
Insert at Last in single linked list
INSERT_LAST(X,FIRST)
Where X is a new element and FIRST, a pointer to the first
element of a linked linear list whose typical node contains INFO and
LINK fields as previously described, this function insert X. AVAIL is a
pointer to the top element of the availability stack; NEW & SAVE are
temporary pointer variable. It is required that X be inserted at the end of
the list.

13. INSERT_LAST(X,FIRST)
Insert at Last in single linked list
Step 1: [Underflow?]
if AVAIL= NULL
then write (“Availability stack underflow”)
return (FIRST)
Step 2: [Obtain address of next free node]
NEW ← AVAIL
Step 3: [Remove free node from availability node]
AVAIL ← LINK(AVAIL)
Step 4: [Initialize fields node from availability stack]
INFO(NEW) ← X
LINK(NEW) ← NULL

14. INSERT_LAST(X,FIRST)
Insert at Last in single linked list
Step 5: [Is the list EMPTY?]
if FIRST= NULL
then Return(NEW)
Step 6: [Initiate search for the last node]
SAVE ← FIRST
Step 7 : [Search for end of list]
Repeat while LINK(SAVE) ≠ NULL
SAVE ← LINK(SAVE)
Step 8 : [Set LINK Field of last node to NEW]
LINK(SAVE) ← NEW
Step 9: [Return first node]
Return(FIRST)

15. INSERT_ORD(X,FIRST)
Insert at Order in single linked list
INSERT_ORD(X,FIRST)
Where X is a new element and FIRST, a pointer to the first
element of a linked linear list whose typical node contains INFO and
LINK fields as previously described, AVAIL is a pointer to the top
element of the availability stack; NEW & SAVE are temporary pointer
variable. It is required that X be inserted so that it preserves the ordering
of the terms in increasing order of their INFO fields.

16. INSERT_ORD(X,FIRST)
Insert at Order in single linked list
Step 1: [Underflow?]
if AVAIL= NULL
then write (“Availability stack underflow”)
return (FIRST)
Step 2: [Obtain address of next free node]
NEW ← AVAIL
Step 3: [Remove free node from availability node]
AVAIL ← LINK(AVAIL)
Step 4: [Copy information contents into new node]
INFO(NEW) ← X
Step 5: [Is the list EMPTY?]
if FIRST= NULL
then Return(NEW)

17. INSERT_ORD(X,FIRST)
Insert at Order in single linked list
Step 6: [Does the new node precede all others in the list?]
if INFO(NEW) ≤ INFO(FIRST)
then LINK(NEW) ← FIRST
Return(NEW)
Step 7 : [Initialize temporary pointer]
SAVE ← FIRST
Step 8 : [Search for predecessor of new node]
Repeat while LINK(SAVE) ≠ NULL and INFO(LINK(SAVE)) ≤ INFO (NEW)
SAVE ← LINK(SAVE)
Step 9 : [Set LINK Field of new node and its predecessor]
LINK(NEW) ← LINK(SAVE)
LINK(SAVE) ← NEW
Step 10: [Return first node]
Return(FIRST)

18. DELETE(X,FIRST)
Delete in single linked list
Where X and FIRST, pointer Variable
whose values denote the address of a node
in linked list and the address of the first
node in the linked list, respectively, this
procedure deletes the node whose address
is given by X. TEMP is used to find the
desired node, and PRED keeps track of the
predecessor of TEMP. note that FIRST is
changed only when X is the first elements
of the list.

19. DELETE(X,FIRST)
Delete in single linked list
Step 1: [EMPTY LIST?]
if FIRST= NULL
then write (“Underflow”)
return
Step 2: [Initialize search for X]
TEMP ← FIRST
Step 3: [Find X]
Repeat thru Step 5 while TEMP ≠ x and
LINK(TEMP) ≠ NULL
Step 4: [Update Predecessor Marker ]
PRED ← TEMP
Step 5: [Move to next node]
TEMP ← LINK(TEMP)

20. DELETE(X,FIRST)
Delete in single linked list
Step 6: [End of the list?]
if TEMP ≠ X
then write(„NODE NOT FOUND”)
return
Step 7: [Delete X]
if X = FIRST (is X the First NODE?)
then FIRST ← LINK(FIRST)
else LINK(PRED) ← LINK(X)
Step 8 : [Return node to availability area]
LINK(X) ← AVAIL
AVAIL ← X
return

21. COPY(FIRST)
Copy in single linked list
Given FIRST, a pointer to the first
node in the linked list, this function makes a
copy of this list. A typical node in the given
list consists of INFO and LINK fields. The new
list is to contain nodes whose information
and pointer fields are denoted by FIELD and
PTR, respectively. The address of the first
node in the newly created list is to be placed
in BEGIN. NEW,SAVE and PRED are pointer
variable.

22. COPY(FIRST)
Copy in single linked list
Step 1: [EMPTY LIST?]
if FIRST= NULL
then write (“Underflow”)
return
Step 2: [Copy first node]
if AVAIL = NULL
then write(„Availability Stack UNDERFLOW‟)
return(0)
else NEW ← AVAIL
AVAIL ← LINK(AVAIL)
FIELD(NEW) ← INFO(FIRST)
BEGIN ← NEW
Step 3: [Initialize traversal]
SAVE ← FIRST

23. COPY(FIRST)
Copy in single linked list
Step 4: [Move to next node if not at the end of list]
Repeat through step 6 while LINK(SAVE) ≠ NULL
Step 5: [Update Predecessor and save pointers ]
PRED ← NEW
SAVE ← LINK(SAVE)
Step 6: [Copy Node]
if AVAIL = NULL
then write(„Availability Stack UNDERFLOW‟)
return(0)
else NEW ← AVAIL
AVAIL ← LINK(AVAIL)
FIELD(NEW) ← INFO(SAVE)
PTR(PRED) ← NEW

24. COPY(FIRST)
Copy in single linked list
Step 7 : [Set Link of last node and return]
PTR(NEW) ← NULL
Return NULL
return

25. Linear Linked List MCQ PPT

26. Linear Linked List MCQ PPT
1)A linear Structure in which the individual elements are joined together by
references to other elements in the structure is known as a_________
•Tree (b) Vector (c) Linked list (d) Table
2)A list that restricts insertions and removals to the front ( or top ) is known as a
(b) Linked list (b) stack (c) queue (d) frontal List
3)To Access an item in a singly linked list you must usa a _______ algorithm.
(b) Traversal (b) access (c) removal (d) insertion
4)Linked lists are collections of data items “lined up in row”-insertions and deletion can be made
only at the front and the back of a linked list.
(b) TRUE (b) FALSE
5)Self-referential objects can be linked together to from useful data structures such as
lists,queues,stacks and tree
(a) TRUE (b) FALSE

27. Linear Linked List MCQ PPT
6)The situation when in a linked list START=NULL is
(a) Underflow (b) overflow (c) housefull (d) saturated
7)The link field in the last node of the linked list contains
(a) NULL (b) link to the first node (c) pointer to the next element (d) Zero value
8)To delete a node at the beginning of the list, the location of the list is modified as the
address of the.
(a) Second element in the list (b)First element in the list (c) Last element in the list.
9) In the linked list representation of the stacks, the top of the stack is represented by
(a)The last node (b) Any of the nodes (c) First node
10) A linked list in which the last node points to the first is called a
(a) Doubly linked list (b) Circular list (c) Generalized list

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