SEMINAR ON LINKED LIST (CIRCULAR AND DOUBLE)Presented by Joydip
Ghosh 3rd Year Roll-08 Department of Information Technology Academy
Of TechnologyJoydip Ghosh (Academy Of Technology)
`
In computer science, a linked list is a data structure that
consists of a sequence of data records such that in each record
there is a field that contains a reference (i.e., a link) to the
next record in the sequence.
Joydip Ghosh (Academy Of Technology)
ANATOMY OF LINKED LISTy A linked list consists of: y A sequence
of nodes
myList a b c d
The list have a header Each node contains a value and a link
(pointer or reference) to some other node The last node contains a
null link
Joydip Ghosh (Academy Of Technology)
y Single linked list
Head
NULL
This is the most basic type of linked list, with each node
containing a single pointer, to the next node.
y Multi linked list
Head
NULL
More advanced than the single linked list, each node may be
connected to many other nodes.Special case : Doubly linked
listsHead
y Circular linked listWith a circular linked list, the last node
is connected to the first, to form a circle.Joydip Ghosh (Academy
Of Technology)
MULTI OR DOUBLY LINKED LISTy In computer science, a
doubly-linked list is a linked data
structure that consists of a set of data records, each having
two special link fields that contain references to the previous and
to the next record in the sequence. It can be viewed as two
singly-linked lists formed from the same data items, in two
opposite orders.
Joydip Ghosh (Academy Of Technology)
Basic Structure Of Double Linked Listy data: the user's data y
next, prev: the address of the next and previous node
in the list
prev
data
next
A
Creation Of Single NodeXNULL NULL
typedef struct dnode { struct dnode *prev; int data; struct
dnode *next; }dn; x=(dn*)malloc(sizeof(dn));
x->prev=x->next=NULL; *head=x;Joydip Ghosh (Academy Of
Technology)
head
Empty Doubly Linked List
c
head// constructor DoubleList() { head = new tail = new
head->next tail->prev }
tail
DoubleListNode (); DoubleListNode (); = tail; = head;Joydip
Ghosh (Academy Of Technology)
Inserting into a Doubly Linked Lista c
head current newNode = new DoublyLinkedListNode()
newNode->prev = current; newNode->next = current->next;
newNode->prev->next = newNode; newNode->next->prev =
newNode; current = newNode
tail
Joydip Ghosh (Academy Of Technology)
Inserting into a Doubly Linked Lista c
head current
b
tail
newNode = new DoublyLinkedListNode() newNode->prev = current;
newNode->next = current->next; newNode->prev->next =
newNode; newNode->next->prev = newNode; current =
newNodeJoydip Ghosh (Academy Of Technology)
Inserting into a Doubly Linked Lista c
head current
b
tail
newNode = new DoublyLinkedListNode() newNode->prev = current;
newNode->next = current->next; newNode->prev->next =
newNode; newNode->next->prev = newNode; current =
newNodeJoydip Ghosh (Academy Of Technology)
Inserting into a Doubly Linked Lista c
head current
b
tail
newNode = new DoublyLinkedListNode() newNode->prev = current;
newNode->next = current->next; newNode->prev->next =
newNode; newNode->next->prev = newNode; current =
newNodeJoydip Ghosh (Academy Of Technology)
Inserting into a Doubly Linked Lista c
head current
b
tail
newNode = new DoublyLinkedListNode() newNode->prev = current;
newNode->next = current->next; newNode->prev->next =
newNode; newNode->next->prev = newNode; current =
newNodeJoydip Ghosh (Academy Of Technology)
Inserting into a Doubly Linked Lista c
head current
b
tail
newNode = new DoublyLinkedListNode() newNode->prev = current;
newNode->next = current->next; newNode->prev->next =
newNode; newNode->next->prev = newNode; current =
newNodeJoydip Ghosh (Academy Of Technology)
Inserting into a Doubly Linked Lista c
head current
b
tail
newNode = new DoublyLinkedListNode() newNode->prev = current;
newNode->next = current->next; newNode->prev->next =
newNode; newNode->next->prev = newNode; current =
newNodeJoydip Ghosh (Academy Of Technology)
Deleting an element from a double linked lista c
head current
b
oldNode=current; oldNode->prev->next = oldNode->next;
oldNode->next->prev = oldNode->prev; current =
oldNode->prev; Joydip Ghosh (Academy Of Technology) delete
oldNode;
Deleting an element from a double linked list
a
c
head current
b oldNode
oldNode=current; oldNode->prev->next = oldNode->next;
oldNode->next->prev = oldNode->prev; current =
oldNode->prev; delete oldNode;
Joydip Ghosh (Academy Of Technology)
Deleting an element from a double linked list
a
c
head current
b oldNode
oldNode=current; oldNode->prev->next = oldNode->next;
oldNode->next->prev = oldNode->prev; current =
oldNode->prev; Joydip Ghosh (Academy Of Technology) delete
oldNode;
Deleting an element from a double linked lista c
head current
b oldNode
oldNode=current; oldNode->prev->next = oldNode->next;
oldNode->next->prev = oldNode->prev; current =
oldNode->prev; Joydip Ghosh (Academy Of Technology) delete
oldNode;
Deleting an element from a double linked list
a
c
head current
b oldNode
oldNode=current; oldNode->prev->next = oldNode->next;
oldNode->next->prev = oldNode->prev; current =
oldNode->prev; delete oldNode;
Joydip Ghosh (Academy Of Technology)
Deleting an element from a double linked list
a
c
head current
oldNode=current; oldNode->prev->next = oldNode->next;
oldNode->next->prev = oldNode->prev; current =
oldNode->prev; delete oldNode;
Joydip Ghosh (Academy Of Technology)
DLLs compared to SLLsAdvantages: Can be traversed in either
direction (may be essential for some programs)Some operations, such
as deletion and inserting before a node, become easierJoydip Ghosh
(Academy Of Technology)
Disadvantages: Requires more space List manipulations are slower
(because more links must be changed) Greater chance of having bugs
(because more links must be manipulated)
Circularly Linked ListsaList
size
3
head
21
24
47
A circularly-linked list is a singly-linked list where the last
Node refers back to the first Node in the list. A tail reference is
not used.Joydip Ghosh (Academy Of Technology)
Traversing a circularly-linked listaList
size
3
head
To traverse a circularly-linked An insertion can be performed
list, move a Node handles until pos after thepair ofthat q
references, == i (or p.getNext( ) == head) and a removal will
remove the Node referenced by p, using q to Locate the node
containing x = 47 reattach the list.
21
24
47
p Node p = head, q; while (p.getNext( ) != head &&
p.getData( ) != x) { q = p; p = p.getNext( ); Joydip Ghosh (Academy
Of Technology) }
q
p
q p
A circularly-linked list with a single NodeaList
Special case List contains a single Node The succ field of a
single Node contains a handle to itself Constructor for
Node21public Node(Object obj) { data = obj; succ = this; }The
object under construction
size
1
head
The only special circumstances about adding the first or
removing the last Node from a circularly-linked list involve
setting the contents of head.Joydip Ghosh (Academy Of
Technology)
Create a Node referring to itself and overwrite the succ field
using setNext( ) when adding to the list if Node is not the first
Node to be added.
APPLICATIONS OF CIRCULAR LINKED LISTJheophus ProblemSTART
2 3
1WINNER
4
5Joydip Ghosh (Academy Of Technology)
FOR NODES NO = 5 FOR COUNT = 3
Joydip Ghosh (Academy Of Technology)
