Linked Lists

In programming, data is stored and manipulated using various structures. One of the most essential and flexible data structures is the Linked List. Unlike arrays, which store elements in contiguous memory locations, linked lists use nodes to store elements dynamically. Each node contains data and a pointer (or reference) to the next node in the sequence. This unique design allows for efficient memory usage and dynamic data handling.

• Linked List is a linear data structure.
• It consists of nodes where each node contains two parts: data and a pointer to the next node.
• It allows efficient insertion and deletion of elements from any position.
• Unlike arrays, linked lists do not require contiguous memory blocks.
• It is commonly used in scenarios where memory size is unknown or changes frequently.

Operations on Linked Lists

• Insertion: Add a new node at the beginning, end, or any position in the list.
• Deletion: Remove a node from the beginning, end, or any position.
• Traversal: Visit each node in the list to read or process data.
• Search: Look for a node with a specific value.
• Update: Modify the data of a specific node.

Types of Linked Lists

Singly Linked List

Each node points to the next node and the last node points to NULL.

Doubly Linked List

Each node points to both the next and the previous node, allowing bidirectional traversal.

Singly Circular Linked List

The last node links back to the first node, forming a circular loop in a single direction.

Doubly Circular Linked List

Similar to a doubly linked list but the last and first nodes are connected, forming a circular structure in both directions.

Difference Between Arrays and Linked Lists

	Array	Linked List
Memory Allocation	Fixed size, contiguous memory	Dynamic size, non-contiguous memory
Insertion/Deletion	Costly and time-consuming	Efficient and flexible
Access Time	Fast with index-based access	Slow, requires traversal
Memory Utilization	May waste memory if size is overestimated	Efficient use of memory
Data Movement	Requires shifting elements	No need to shift elements

Benefits of Using Linked Lists

• Dynamic memory allocation enables flexibility with memory usage.
• Insertion and deletion operations are easier and more efficient.
• Useful for implementing stacks, queues, graphs, and other complex data structures.
• Can efficiently handle frequent modifications in data.
• Does not require memory reallocation like arrays.