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Linked List Interview Questions

Linked-list problems reward careful pointer bookkeeping over cleverness: reverse in place, find the middle with fast and slow pointers, detect a cycle, or merge two sorted lists. A dummy head node removes most of the edge cases people trip on. Draw the pointers before you write - almost every bug here is an off-by-one on the node you already moved past.

Recognise it when you see

Any problem handing you a list head, especially with an O(1) space constraint.

12 problems. Each one runs in an in-browser editor against real test cases, with hints and a worked solution.

Easy7

Merge Two Sorted ListsPremium

EasyTwo Pointers

Reverse Linked ListPremium

Easy

Linked List CyclePremium

EasyTwo Pointers

Middle of the Linked ListPremium

EasyTwo Pointers

Remove Linked List ElementsPremium

Easy

Palindrome Linked ListPremium

EasyTwo Pointers

Remove Duplicates from Sorted ListPremium

Easy

Medium2

Add Two NumbersPremium

MediumMath

Remove Nth Node From End of ListPremium

MediumTwo Pointers

Hard3

Merge k Sorted ListsPremium

HardHeap / Priority QueueDivide & Conquer

LRU CachePremium

HardDesignArrays & Hashing

LRU Cache (Operations API)Premium

HardDesignArrays & Hashing

Learn the triggers, not just the templates

The patterns cheat sheet covers all of these in one page - what each one looks like in a problem statement, and the template that follows.

Interview patterns cheat sheet Big-O cheat sheet All coding problems

Linked List Interview Questions

Linked-list problems reward careful pointer bookkeeping over cleverness: reverse in place, find the middle with fast and slow pointers, detect a cycle, or merge two sorted lists. A dummy head node removes most of the edge cases people trip on. Draw the pointers before you write - almost every bug here is an off-by-one on the node you already moved past.