Minimum Deletions to Make Array Divisible
A hard-tier problem at 58% community acceptance, tagged with Array, Math, Sorting. Reported in interviews at LinkedIn and 0 others.
You're looking at a problem LinkedIn asks: how to delete the minimum elements from an array so the remaining elements are all divisible by some target. With just over a 57% acceptance rate, this is a trap problem. Most candidates jump to a greedy approach and miss the math. The trick isn't about deletions at all. It's about finding the GCD of the remaining array and understanding which elements you actually need to keep. LinkedIn's asking this to spot candidates who can spot the structural problem hiding inside the algorithmic one.
Companies that ask "Minimum Deletions to Make Array Divisible"
Minimum Deletions to Make Array Divisible 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. Built by a senior engineer who knows the OA is theater. This is the script.
Get StealthCoderThe brute force path is tempting but wrong: iterate through possible deletion counts and check divisibility each time. The real insight is that the final array must be divisible by some divisor, and that divisor has to divide the GCD of all remaining elements. So you compute the GCD of every possible subset, then find the smallest GCD value. Once you have that target GCD, count how many deletions get you there. The sorting and heap topics point to optimization: you can sort the array, compute prefix GCDs, and binary search or iterate smartly. Common pitfall: thinking the answer is a fixed divisor like the array's total GCD. It's not. You choose the divisor that minimizes deletions. If you hit this on your assessment and the pattern doesn't click, StealthCoder solves it in seconds without the proctor seeing a thing.
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Minimum Deletions to Make Array Divisible recycles across companies for a reason. It's hard-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. Built by a senior engineer who knows the OA is theater. This is the script. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Minimum Deletions to Make Array Divisible interview FAQ
Is this really a hard problem or just long?+
It's actually hard. The 57% acceptance rate reflects candidates who implement a slow brute force or misunderstand the GCD relationship. The trick is clean once you see it, but the jump from 'minimum deletions' to 'find the optimal GCD' isn't obvious without number theory intuition.
Do I need to know advanced number theory?+
No. You need to know GCD computation and how it works on subsets. Understanding that GCD is associative and that the remaining array's divisor must divide the GCD of that array is the only theory you need. Linear time GCD is enough.
Why does LinkedIn ask this?+
It tests two things: can you recognize that the problem is really about GCD, not greedy deletions. Can you optimize from exponential to polynomial time. LinkedIn values candidates who spot structure in ambiguous problems.
How do I know when to use sorting and heap here?+
Sorting lets you compute prefix GCDs efficiently. Heap isn't strictly necessary but can help if you're tracking multiple GCD candidates. For most accepted solutions, sorting and iteration is enough. Skip heap unless your first pass times out.
What's the most common wrong answer?+
Computing the GCD of the entire array once and treating it as the target. Real answer: you must try multiple target GCDs and pick the one that minimizes deletions. That's the O(n^2) or O(n log n) insight most fail to reach.
Want the actual problem statement? View "Minimum Deletions to Make Array Divisible" on LeetCode →