Min Operations
Reported by candidates from Amazon's online assessment. Pattern, common pitfall, and the honest play if you blank under the timer.
Amazon asked this in December 2024, and it's a trap disguised as a simple optimization problem. You get a number or array, and you need to minimize operations to reach some goal state. The catch is that most candidates jump to greedy or brute force first, then realize mid-interview they missed the optimal substructure. This is where dynamic programming or math reasoning lives. If you blank on the pattern live, StealthCoder reads the problem and spots the recurrence or the mathematical shortcut in real time.
Pattern and pitfall
Min Operations problems typically hide a DP state or a mathematical formula. The real test is recognizing whether you're counting steps in a transformation (DP, BFS) or whether there's a closed-form answer (math, number theory). Amazon loves asking variants where greedy fails on non-obvious test cases. The common pitfall is assuming one operation is always better than another without proving it works for all inputs. When you're live and stuck between two approaches, having a safety net like StealthCoder means you can see how the problem is phrased, recognize the constraint bounds, and get the pattern name in seconds rather than burning 15 minutes on a wrong path.
If this hits your live OA and you blank, StealthCoder solves it in seconds, invisible to the proctor.
You can drill Min Operations 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. Built by an Amazon engineer who would have shipped this the night before his JPMorgan OA if he'd had it.
Get StealthCoderRelated leaked OAs
You've seen the question.
Make sure you actually pass Amazon's OA.
Amazon reuses patterns across OAs. Built by an Amazon engineer who would have shipped this the night before his JPMorgan OA if he'd had it. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Min Operations FAQ
Is this a DP problem or a math problem?+
Without the exact problem statement, both are live possibilities. If the problem asks for the count of steps to transform one state to another, think DP or BFS first. If it's asking for a formula based on input size or value, math or greedy. The reported title 'Min Operations' leans DP, but Amazon hides math tricks in the constraints.
What's the most common pitfall candidates miss?+
Assuming one operation is always optimal. Test your greedy logic against small examples where the operation costs differ or where order matters. Also watch for off-by-one errors in counting or forgetting that some operations may not be allowed for all inputs.
How do I spot if it's a DP problem in 60 seconds?+
Ask yourself: does the problem have overlapping subproblems (same state reachable multiple ways) and optimal substructure (best solution contains best solutions to subproblems). If yes to both, DP. Min Operations problems often have both.
Is this still being asked at Amazon in late 2024?+
Yes, December 2024 confirms it's active. Amazon cycles through optimization and operation-counting problems regularly. The pattern is stable, and the difficulty typically sits at medium to hard depending on constraints and the specific operation set.
What should I code first if I'm unsure?+
Start with a recursive or memoized DP approach. It's safer than greedy and easier to debug live. Code the base case, the recurrence, and one small example. If it's math, you'll see it fast. If it's DP, you've bought yourself time and a working solution.