The Mirror Index
A easy Python mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Python
- Difficulty
- easy
- Seniority
- L4
Interview Prompt
A search index `d` maps each document id to the single term it matched, and serving lookups needs the inverse: each term pointing back to its documents. Return a new dict whose keys are the unique terms and whose values are the sorted document ids that had that term, keyed as JSON so each term is stringified (the term `1` becomes `"1"`).
Summary
Every value remembers who pointed to it.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your python solution with real code execution
- Get instant feedback and a hire/no-hire decision