1. StudentName : Vinay Kamriya
StudentName : Vinay Kamriya
Year/Branch : 3rd year (CS)
Topic : Linked List
2. Table of content
• Introduction
• Keeping track of linked list
• Basic operations
– Traversing
– Insertion
– Insertion
– Deletion
• Types of linked list
– Singly linked list
– Circular linked list
– Doubly linked list
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3. Introduction
• A linked list is a data structure which can change
during execution.
– Successive elements are connected by pointers.
– Last element points to NULL.
– It can grow or shrink in size during execution of a
– It can grow or shrink in size during execution of a
program.
– It can be made just as long as required.
– It does not waste memory space.
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A B C
head
4. • Keeping track of a linked list:
– Must know the pointer to the first element of the
list (called start, head, etc.).
• Linked lists provide flexibility in allowing the
items to be rearranged efficiently.
items to be rearranged efficiently.
– Insert an element.
– Delete an element.
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5. Basic Operations on a List
• Traversing the list
• Inserting an item in the list
• Deleting an item from the list
• Deleting an item from the list
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6. Traversing a linked list
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Time complexcity of traversing an linkedlist
- O(n)
7. Pseudo-code for traversal
public static void traversal(Node head)
{
while(head!=null)
{
{
System.out.print(head.data + " ");
head = head.next;
}
}
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9. •For insertion:
–A record is created holding the new
item.
–The next pointer of the new record is
set to link it to the item which is to
follow it in the list.
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follow it in the list.
–The next pointer of the item which is
to precede it must be modified to point
to the new item.
10. Pseudo-code for insertion
public static Node insertAtFirst(Node head , int
data)
{
Node newNode = new Node(data);
newNode.next = head;
return newNode;
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return newNode;
}
11. Illustration: Deletion
A B C
Item to be deleted
curr
tmp
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A B C
curr
12. • For deletion:
– The next pointer of the item immediately
preceding the one to be deleted is altered, and
made to point to the item following the deleted
item.
item.
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13. Pseudo-code for deletion
public static Node deletionAtFirst(Node
head)
{
head = head.next;
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head = head.next;
return head;
}
14. Types of Lists
• Depending on the way in which the links are
used to maintain adjacency, several different
types of linked lists are possible.
– Linear singly-linked list (or simply linear list)
• One we have discussed so far.
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A B C
head
15. – Circular linked list
• The pointer from the last element in the list points back
to the first element.
head
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A B C
16. – Doubly linked list
• Pointers exist between adjacent nodes in both
directions.
• The list can be traversed either forward or backward.
• Usually two pointers are maintained to keep track of
• Usually two pointers are maintained to keep track of
the list, head and tail.
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A B C
head tail
