Rotate Array
A medium-tier problem at 43% community acceptance, tagged with Array, Math, Two Pointers. Reported in interviews at DXC Technology and 28 others.
Rotate Array shows up in interviews at DXC Technology, Scale AI, Accenture, Zoho, Wipro, American Express, Razorpay, Walmart Labs, Infosys, and TCS, plus 19 other companies. With a 43% acceptance rate, it's the kind of problem that looks trivial on paper but trips up candidates who haven't locked in the pattern. You know the setup: shift every element k positions to the right, wrap around the end. The trap is thinking you can just splice and concat, or worse, brute-force rotate one element at a time. That's where the real trick hides, and if you blank on it live, StealthCoder solves it invisibly in seconds.
Companies that ask "Rotate Array"
Rotate Array 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 an Amazon engineer who used it to pass JPMorgan's OA and system design loop.
Get StealthCoderThe obvious solutions fail under time pressure. Naive rotation is O(n*k) and will timeout on large inputs. Building a new array works but isn't elegant. The actual pattern is the reverse algorithm: reverse the entire array, then reverse the first k elements, then reverse the rest. It's O(n) time, O(1) space, and uses only Two Pointers logic. Most candidates either miss this entirely or second-guess themselves mid-implementation. The Math insight is recognizing that rotation is modular arithmetic: k = k % n handles k larger than array length. This problem tests whether you can spot the non-obvious O(1) space solution under pressure. If you hit this live and freeze, StealthCoder surfaces the working reverse pattern before you lose momentum.
Pattern tags
You know the problem.
Make sure you actually pass it.
Rotate Array 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. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Rotate Array interview FAQ
Is Rotate Array actually hard or just pattern recognition?+
It's pure pattern recognition. The algorithm is simple once you see it, but 57% of candidates don't. The trick is reversing subarrays, not rotation itself. If you know the pattern, you're done in five minutes. If you don't, you'll waste time on suboptimal approaches.
Do I really need O(1) space or is O(n) acceptable?+
Both work. O(n) space solutions pass most platforms. But O(1) space (the reverse algorithm) is what experienced engineers build and what interviewers respect. Companies like Walmart Labs and American Express specifically test optimization thinking.
What if k is larger than the array length?+
You must use modulo: k = k % n. Rotating by n is the same as no rotation. This detail trips up rushed candidates. The Math topic in this problem is exactly this insight.
How does this relate to Two Pointers?+
The reverse algorithm is a Two Pointers technique. You maintain left and right pointers, swap elements, and move inward. It's the same pattern used in reverse strings or palindrome checks.
Will this problem appear in my assessment?+
29 companies have reportedly asked it, including several in fintech and enterprise software. Acceptance rate of 43% means it's common enough that you shouldn't skip it. It's a solid hedge to drill before your OA.
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