The base case is pretty straightforward, sort and index.
Start by clarifying constraints (e.g., array size, value range, duplicates, whether k is 1-indexed). Then present multiple solutions: sorting (O(n log n)), min-heap of size k (O(n log k)), and Quickselect (average O(n)). Discuss trade-offs and choose the best based on constraints, mentioning edge cases and potential optimizations.
Pro tip: Meta values production-ready code and trade-off analysis. After presenting the optimal solution, mention how you would handle duplicates (e.g., using a hash map or three-way partitioning) and discuss the worst-case of Quickselect (O(n^2)) and how to mitigate it with random pivot selection.
Ask about input size, value range, duplicates, and whether k is 1-indexed. Confirm expected time/space complexity and if the array can be modified.
Outline sorting, min-heap, and Quickselect. Briefly explain each and their time/space complexities.
Compare approaches: sorting is simple but O(n log n); heap is O(n log k) and good for streaming; Quickselect is average O(n) but worst-case O(n^2). Choose based on constraints.
Write clean code for the selected approach, handling edge cases like k=1, k=n, empty array, and duplicates.
Walk through examples, test edge cases, and discuss potential optimizations (e.g., random pivot, early termination).
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.