DSA Pattern Guide
Linked List Interview Patterns
Almost every linked-list interview question reduces to one of three techniques: the fast/slow (Floyd's) pointer for cycle detection and finding the middle, in-place pointer reversal, and a dummy-head node to simplify edge cases at the list's start. Once you recognize which one a problem needs, the code is usually under 15 lines.
11
Questions in Ediky's DSA-Technical bank
MCQ / trace, not code-judged
Bank
Ediky's code-judged DSA bank (/problems) doesn't have a dedicated Linked List topic yet — the real coverage right now is 11 trace/MCQ questions in the DSA-Technical bank, which tests whether you can reason about pointer manipulation precisely rather than just write code for it.
The patterns that matter
- Fast/slow pointers (Floyd's algorithm) — cycle detection, and finding both the cycle AND its starting node
- In-place reversal — reversing a list (or a sublist) using three pointers, O(1) space
- Two-pointer intersection — finding where two lists merge in O(1) extra space
- Palindrome check in O(1) space — combining fast/slow with in-place reversal of the second half
Real questions from Ediky's DSA-Technical bank
Actual question titles:
- "Floyd's Algorithm Detected a Cycle. How Do You Find Its Starting Node?"
- "Intersection of Two Linked Lists in O(1) Extra Space"
- "Palindrome Check on a Linked List in O(n) Time, O(1) Space"
Practice Linked List questions
11 trace/MCQ questions in Ediky's DSA-Technical bank — sign in to access.
Open Linked List questions