Linked List

A Linked List is a fundamental data structure that consists of a sequence of elements, where each element points to the next element in the sequence. Unlike arrays, linked lists don't store elements in contiguous memory locations, making them dynamic and flexible for insertions and deletions.

1. Basic Concepts:
   • Nodes contain data and reference to next node
   • First node is called the head
   • Last node points to null
   • Dynamic size allocation
2. Common Operations:
   • Insertion at beginning, end, or middle
   • Deletion of nodes
   • Traversal through the list
   • Searching for elements
   • Updating node values
3. Key Advantages:
   • Dynamic size (grows/shrinks as needed)
   • Efficient insertions and deletions
   • No memory wastage

Complexity Analysis of Linked List Operations

Different operations in a linked list have varying time complexities:

• Time Complexity:
  • Access: O(n) - must traverse from head
  • Insertion at beginning: O(1)
  • Insertion at end: O(n) or O(1) with tail pointer
  • Deletion: O(n) to find, O(1) to delete
  • Search: O(n) - linear search required
• Space Complexity: O(n)
  • Each node requires extra space for next pointer
  • Space grows linearly with number of elements

Types of Linked Lists:

• Singly Linked List (next pointer only)
• Doubly Linked List (previous and next pointers)
• Circular Linked List (last node points to first)
• Circular Doubly Linked List
• Header Linked List

Common Applications:

• Implementation of stacks and queues
• Symbol table management in compilers
• Undo functionality in software
• Memory allocation in operating systems
• Music playlist management