Coding problem: Most Frequent Terms. Given a list of lowercase `words` and an integer `k`, return the `k` most frequent distinct words, most frequent first. Break ties alphabetically, using plain character order (so `"ant"` comes before `"bee"`, and `"car"` before `"cart"`).

What the interviewer is looking for

• What a strong solution looks like: count with a hash map, then sort the distinct words by (-count, word) and take k: O(n + d log d) for d distinct words. A size-k heap gives O(n + d log k); bucket sort by count is O(n + d log d) worst case but fast. Any of these is fine if they can explain it.
• Think aloud. Interviewers are judging how you reason, not only the final code.
• Be ready for: The words arrive as an endless stream — keep an approximate top-k in bounded memory (space-saving, count-min sketch). Data is sharded across machines: why isn't merging each shard's top-k exact? Write it in SQL (GROUP BY, ORDER BY count DESC, word, LIMIT k).

A structure to follow: Clarify, plan, code, test, analyse

1. Step 1

   Clarify

   Restate the problem, ask about empty input, duplicates and size limits, and agree on one example.

2. Step 2

   Plan

   Say the simple approach first and its cost, then the better one. Explain why before you type.

3. Step 3

   Code

   Write small named steps and talk through each. A clear solution beats a clever one.

4. Step 4

   Test

   Walk your own example through the code, then an edge case. Fix what you find calmly.

5. Step 5

   Analyse

   State time and space cost in plain words and say what you would change for much larger input.

This is guidance on shape, not a script. Use your own real experience and facts; never invent details to fill a gap. See the STAR guide and answer frameworks.

Common slips

• Starting to code before agreeing what the answer must be.
• Going silent when stuck instead of saying what you are trying.
• Never running your own example through the code.

How to practise it

Solve it once in the editor without hints, then explain your solution aloud in under two minutes.

Related questions

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