Find X Value of Array I
A medium-tier problem at 33% community acceptance, tagged with Array, Math, Dynamic Programming. Reported in interviews at Rubrik and 0 others.
Find X Value of Array I is a medium-difficulty problem that shows up in Rubrik's assessment pipeline. With a 33% acceptance rate, most candidates either miss the mathematical insight or implement a solution that looks right but times out. This problem sits at the intersection of array manipulation and math reasoning, which means the naive approach almost always fails. If you haven't drilled the pattern before, you could blank on it mid-interview. StealthCoder runs invisibly during your OA and surfaces a working solution the moment you hit the wall, so you can move forward and finish stronger.
Companies that ask "Find X Value of Array I"
Find X Value of Array I is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Made by a working FAANG engineer who treats the OA the way companies treat hiring: as a game with rules you should know.
Get StealthCoderThe trick here is recognizing that a straightforward simulation will TLE. Most candidates try to iterate and update the array directly, which works for small inputs but collapses on scale. The math insight rewrites the problem: instead of simulating X deletions, you can calculate the final value algebraically or use dynamic programming to avoid redundant work. The problem tests whether you can spot when an obvious approach is a trap and pivot to the underlying pattern. Many solutions fail because they don't compress the logic or miss that certain deletions follow a predictable sequence. When you're live in the assessment and your first attempt times out with only minutes left, StealthCoder shows you the optimized approach instantly, no trial and error needed.
Pattern tags
You know the problem.
Make sure you actually pass it.
Find X Value of Array I recycles across companies for a reason. It's medium-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Made by a working FAANG engineer who treats the OA the way companies treat hiring: as a game with rules you should know. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Find X Value of Array I interview FAQ
Is 'Find X Value of Array I' really asked at FAANG or is this a Rubrik-only thing?+
It's a Rubrik assessment problem, so it won't appear in Google or Meta interviews. That said, the underlying pattern (optimization via math or DP instead of simulation) is universal. If you're targeting Rubrik specifically, this problem is high-priority. For others, it's a good warm-up for recognizing when simulation fails.
What's the actual trick I'm missing if my brute-force times out?+
You're probably simulating each step sequentially. The trick is recognizing that X deletions follow a pattern you can calculate or memoize rather than simulate. Once you see the recurrence or closed-form relationship, the solution compresses dramatically. This is where dynamic programming or mathematical reformulation kicks in.
Do I really need to know advanced math to solve this, or is it mostly logic?+
It's more logic and pattern recognition than advanced math. You need to think in terms of state transitions and either memoize or derive a formula. If you understand how values change after each operation, you can code the solution without heavy math background.
How does this problem relate to the other array topics, and what should I study first?+
Array fundamentals (indexing, slicing, iteration) are prerequisites. Then focus on dynamic programming concepts like memoization and state definition. The math component is about recognizing invariants and relationships, not calculus or number theory, so don't overthink it.
With a 33% acceptance rate, am I missing something obvious or is it just hard?+
The low rate reflects that most solutions pass test cases but fail on time complexity. It's not a trick question, it's a pattern-spotting problem. Once you see the optimization, it clicks. Candidates who solve it usually study the DP or math angle, not just the surface-level simulation.
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