Linked List

LeetCode problem #2816

Add two numbers represented as linked lists where digits are stored in reverse order

Detect if a linked list has a cycle and find the starting point of the cycle

Create a deep copy of a linked list where each node has a random pointer

Detect if a linked list has a cycle using Floyd's cycle detection algorithm

Find the middle node of a linked list using the two-pointer technique

Flatten a binary tree into a linked list in-place using preorder traversal.

Flatten a multilevel doubly linked list into a single level

Implement a queue using arrays or linked lists with O(1) time complexity for all operations.

Design and implement a stack data structure with push, pop, top, and empty operations

Find the intersection node of two linked lists

Learn the optimal O(1) in-place “copy-and-skip” to delete a node in a linked list without head/prev. Easy interview prep—see examples.

Reverse linked list in k groups (Hard): in-place pointer reversal with dummy node. Optimal O(n) time, O(1) space—step-by-step solution.

Design a data structure that follows Least Recently Used (LRU) eviction with O(1) get and put operations.

Merge k sorted linked lists into one sorted linked list

Merge two sorted linked lists into one sorted linked list

Check if a linked list is a palindrome using O(1) extra space

Partition a linked list around a value x such that all nodes less than x come before nodes greater than or equal to x

Remove all duplicate values from a sorted linked list

Remove the nth node from the end of a linked list in one pass

Reorder a linked list by interleaving nodes from the beginning and end

Reverse a singly linked list in-place and return the new head.

Learn how to reverse a singly linked list (LeetCode 206) with the optimal 3-pointer iterative method: O(n) time, O(1) space. Practice now.

Rotate a linked list to the right by k places

Sort a linked list in O(n log n) time using constant extra space

Swap every two adjacent nodes in a linked list