This document discusses linked lists and their advantages over arrays. It defines linked lists as dynamic data structures that store elements non-contiguously in memory. Each element of a linked list, called a node, contains a data field for its value and a pointer field for the next node. The document describes singly linked lists, which have one pointer per node pointing to the next, and their basic operations like insertion, deletion, display and search. It also provides code for defining the structure of linked list nodes and using malloc() to dynamically allocate memory for new nodes.

1. Introduction to Linked List

2. Advantages and Disadvantages of Arrays
Advantages of array implementation:
• The elements are faster to access using random access.
• Searching an element is easier.
Limitation of array implementation
• The number of elements in the array is fixed.
• Insertion and deletion operation in array are expensive.
• Memory is allocated at compile time i.e static memory allocation.

3. Linked list
• Linked list is an ordered collection of elements which are connected by
links/pointers.
• Memory is allocated at run time i.e. dynamic memory allocation.
• New elements can be stored anywhere in the memory (non contiguous memory
location)
• Each node contains two fields namely,
• Data field-The data field contains the actual data of the elements to be stored in
the list.
• Next field- Address of the next data items.

4. Linked list representation
data next data next data null
HEAD
Data Next
5 10 15
Head Node
Node •Data field-The data
field contains the actual
data of the elements to
be stored in the list.
•Next field- Address of
the next data items.

5. Types of Linked List
• Singly Linked List
• Doubly Linked List
• Circular Linked List

6. Singly Linked list
5 1000 10 2000 15
Head Node
1000 2000
A singly linked list is a linked list in which each node contains only one
link field pointing to the next node in the list.

7. Singly Linked list with Header
• The header node is at the very beginning of the linked list.
• It is an extra node kept at the front of a list.
• Does not represent an item in the linked list.
• It contains the address of the first node.
5 1000 10 2000 15
Header
node
1000

8. Operations on SLL
Basic operations on a singly-linked list are:
◦ Insert – Inserts a new node in the list.
◦ Delete – Deletes any node from the list.
◦ Display-display the date in the list
◦ Search-find whether a element is present in the list or not

9. Singly Linked List - Structure Definition
struct node
{
int data;
struct node * next;
};
Next
Data
Size of this Structure:
For Integer: 4 bytes
For Pointer : 4 Bytes
Totally : 8 bytes

10. malloc()
malloc()
The malloc function reserves a block of memory of specified size and returns a
pointer (starting address of the memory block).
The general syntax of malloc() is
ptr =(cast-type*)malloc(byte-size);
Example:
newnode=(struct node*)malloc(sizeof(struct node));

11. malloc()
newnode=(struct node*)malloc(sizeof(struct node));
8 bytes
newnode 
8 bytes of memory
will be allocated