Get Triplet Count
Reported by candidates from Rubrik's online assessment. Pattern, common pitfall, and the honest play if you blank under the timer.
You're facing Rubrik's Get Triplet Count problem in November. This is a counting question that asks you to find how many valid triplets exist in an array based on some constraint. The trap is overthinking the brute force. Most candidates jump to fancy optimization when a clean nested loop or hash-table approach solves it fast enough. If you blank on the exact constraint during the OA, StealthCoder runs invisibly on your screen and feeds you the pattern in real time.
Pattern and pitfall
Triplet count problems typically fall into two buckets: either you're counting triplets that satisfy a mathematical condition (like sum equals a target, or indices follow a rule), or you're validating a structural property. The common pitfall is writing O(n^3) brute force when O(n^2) with a hash table or two-pointer technique works. If the problem asks for triplets where a + b + c equals a target, you can fix one element and use a two-pointer or hash-based approach on the remaining array. If it's counting distinct or valid triplets by index, sorting plus two pointers becomes your friend. During the live OA, if the exact constraint slips your mind, StealthCoder reads the problem statement and surfaces the optimal pattern so you don't waste 20 minutes on the wrong approach.
Memorize the pattern. If you can't, run StealthCoder. The proctor sees the IDE. They don't see what's behind it.
You can drill Get Triplet Count 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 by an engineer who treats the OA as theater. If yours is tonight, you don't have time to grind. You have time to hedge.
Get StealthCoderRelated leaked OAs
This OA pattern shows up on LeetCode as 3sum. If you have time before the OA, drill that.
You've seen the question.
Make sure you actually pass Rubrik's OA.
Rubrik reuses patterns across OAs. Made by an engineer who treats the OA as theater. If yours is tonight, you don't have time to grind. You have time to hedge. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Get Triplet Count FAQ
Is this asking for distinct triplets or all triplets?+
The distinction matters hugely for your solution. If distinct, you'll sort and skip duplicates. If all triplets count, you tally every valid index combo. Rubrik problems usually clarify in the examples, so read them twice before coding.
Can I use a brute force triple loop?+
Technically yes if array size is under 500-1000. But Rubrik expects O(n^2) or better. Hash table or two-pointer after sorting is the standard move. Brute force will TLE on larger inputs.
What if the constraint involves indices, not values?+
Read the problem statement carefully. Some triplet problems care about index relationships (i < j < k) not sums. If that's the case, you might need counting or prefix-sum logic, not sorting.
Should I sort the array first?+
If the problem is value-based (like sum), sorting is usually safe because you can still track original indices if needed. If it's index-based, sorting breaks the structure, so don't. The problem text will make this clear.
How much time should I spend on this in the OA?+
15-20 minutes max for a clean solution. If you're stuck after 10 minutes on the approach, sketch the brute force, code it, then optimize. Don't chase perfect on your first draft.