Cyclic Pairs
Reported by candidates from DataBricks's online assessment. Pattern, common pitfall, and the honest play if you blank under the timer.
DataBricks hit you with Cyclic Pairs in August, and you've got 24-48 hours to lock it down. This is a pattern-recognition problem that looks deceptive at first read, but once you see the cycle, it clicks. The trick is understanding what "cyclic" actually means in context, then writing clean iteration logic. StealthCoder will catch you if you blank on the traversal order during your live OA.
Pattern and pitfall
Cyclic Pairs almost always boils down to detecting or constructing cycles in a structure, usually using a hash table or set to track visited elements and a pointer-chase approach. The gotcha is that candidates over-engineer it or miss the cycle entirely, treating it as a linear problem. You're likely dealing with a sequence where element A points to element B which eventually points back to A, and you need to count pairs, validate cycles, or reconstruct the order. Hash table for membership checking plus a two-pointer or next-reference traversal pattern are your tools. StealthCoder sits there as your safety net if you freeze on the exact traversal logic during the OA.
Drill it cold or hedge it with StealthCoder. Either way, don't walk into the OA hoping you remember the trick.
You can drill Cyclic Pairs cold, or you can hedge it. StealthCoder runs invisibly during screen share and surfaces a working solution in under 2 seconds. The proctor sees the IDE. They don't see what's behind it. Made for the candidate who got the OA invite this morning and has 72 hours, not six months.
Get StealthCoderRelated leaked OAs
This OA pattern shows up on LeetCode as linked list cycle. If you have time before the OA, drill that.
You've seen the question.
Make sure you actually pass DataBricks's OA.
DataBricks reuses patterns across OAs. Made for the candidate who got the OA invite this morning and has 72 hours, not six months. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Cyclic Pairs FAQ
Is this asking me to detect cycles or build them?+
The problem title doesn't reveal it, but DataBricks typically asks you to either detect pairs that form cycles or count valid cyclic structures. Read the examples carefully for the direction. If you see index-to-index or node-to-node pointers, assume cycle detection.
Do I need a graph library or can I use a hash table?+
Hash table plus simple next pointers is sufficient. You don't need a full graph library. Track visited elements in a set, follow the pointers, and detect when you loop back. That's the core logic.
What if there are multiple cycles?+
Iterate through unvisited elements and spawn a new traversal for each. Mark all visited elements so you don't re-count. This is standard multi-component cycle handling.
Is this still asked after August 2024?+
Yes. Cycle problems are evergreen at DataBricks and similar companies. The pattern shows up in different disguises, but the core traversal stays the same.
Can I solve this in 20 minutes if I recognize the pattern?+
Absolutely. Once you know it's a cycle problem, the hash table and pointer-chase code is straightforward. The time sink is usually edge cases like self-loops or empty inputs.