Linked List Data Structure

A linked list is a fundamental data structure in computer science. It mainly allows efficient insertion and deletion operations compared to arrays. Like arrays, it is also used to implement other data structures like stack, queue and deque.

A linked list is a type of linear data structure individual items are not necessarily at contiguous locations. The individual items are called nodes and connected with each other using links.

• A node contains two things first is data and second is a link that connects it with another node.
• The first node is called the head node and we can traverse the whole list using this head and next links.

Here’s the comparison of Linked List and Arrays

Linked List:

• Data Structure: Non-contiguous
• Memory Allocation: Typically allocated one by one to individual elements
• Insertion/Deletion: Efficient
• Access: Sequential

Array:

• Data Structure: Contiguous
• Memory Allocation: Typically allocated to the whole array
• Insertion/Deletion: Inefficient
• Access: Random

Basics

• Singly Linked List
• Doubly Linked List
• Circular Linked List
• Applications and Advantages

Operations

• Length of Linked List
• Print Linked List
• Search in a Linked List
• Linked List Insertion
• Deleting a given key
• Deleting at given position
• Delete a Linked List
• Nth Node from Start
• Nth Node from End
• Size of Doubly Linked List

Easy Problems

• Remove every k-th node
• Middle of a Linked List
• Count Occurrences in a Linked List
• Circular Linked List Traversal
• Check if Circular
• Count Nodes in Circular List
• Deletion from a Circular Linked List
• Singly to circular Conversion
• Exchange first and last nodes in Circular
• Delete in a Doubly Linked List
• Reverse a Singly Linked List
• Reverse a Doubly Linked List

Medium Problems

• Swap Nodes in Pairs
• Detect loop in a linked list
• Length of loop in linked list
• Design Browser History
• Remove duplicates from a sorted linked list
• Remove Duplicates from an Unsorted Linked List
• Intersection of two Sorted Linked Lists
• Partition a List
• QuickSort on Singly Linked List
• Split a Circular Linked List into two halves
• Merge Two Sorted Linked Lists
• Union and Intersection
• Merge Sort for Doubly Linked List
• Pairs with Sum in doubly linked list
• Insert in sorted way in doubly linked list
• Remove duplicates from an unsorted DLL
• Rotate a Linked List
• Rotate Doubly linked list by N nodes
• Delete a node with only its pointer given
• Segregate even and odd nodes

Hard Problems

• Merge K Sorted Lists
• Intersection point of two Linked Lists.
• Implement LRU Cache
• Clone a linked list with random pointer
• Binary Tree to Doubly Linked List
• Reverse a Singly Linked List in Groups
• Reverse a Doubly Linked List in Groups
• Sublist Search
• Linked list from 2D matrix
• Rotate Linked List block wise
• Multiply two numbers as Lists
• Delete N nodes after M nodes

Quick Links :

• Practice Linked List
• Quiz on Linked List
• DSA Tutorial