Got to a working solution after a few iterations but the interviewer kept pushing back even after we both verbally agreed the approach was sound at a high level.
Start by restating the problem and clarifying assumptions, then propose a straightforward brute-force solution that handles basic cases. As constraints are introduced, iteratively refine the solution by optimizing time/space complexity and addressing edge cases, explaining trade-offs at each step.
Pro tip: Demonstrate proactive thinking by identifying potential edge cases and constraints before the interviewer introduces them, and always discuss the trade-offs of each refinement to show engineering maturity.
Restate the problem in your own words, ask clarifying questions about input ranges, expected output, and constraints. Confirm edge cases like empty input, large values, or duplicates.
Outline a simple, correct solution (e.g., brute-force) that works for small inputs. Explain its time and space complexity and verify it against basic examples.
Analyze the initial solution's weaknesses, such as inefficiency for large inputs or failure on specific edge cases. List concrete edge cases to test.
As constraints are introduced (e.g., time limit, memory limit, specific input properties), optimize the solution using appropriate data structures or algorithms. Explain the trade-offs of each refinement.
Walk through the refined solution with edge cases and typical inputs. Discuss potential further optimizations or alternative approaches if time permits.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.