Deep dive
Expanding on the short answer — what usually matters in practice:
- Context (tags): quickselect, selection, partition, big-o
- Complexity: compare typical operations (average vs worst-case).
- Invariants: what must always hold for correctness.
- When the choice is wrong: production symptoms (latency, GC, cache misses).
- Explain the "why", not just the "what" (intuition + consequences).
- Trade-offs: what you gain/lose (time, memory, complexity, risk).
- Edge cases: empty inputs, large inputs, invalid inputs, concurrency.
Examples
A tiny example (an explanation template):
// Example: discuss trade-offs for "quickselect:-what-is-it-used-for-and-what-is-its"
function explain() {
// Start from the core idea:
// Quickselect finds the k‑th smallest/largest element without fully sorting the array. It us
}
Common pitfalls
- Too generic: no concrete trade-offs or examples.
- Mixing average-case and worst-case (e.g., complexity).
- Ignoring constraints: memory, concurrency, network/disk costs.
Interview follow-ups
- When would you choose an alternative and why?
- What production issues show up and how do you diagnose them?
- How would you test edge cases?