Start by clarifying requirements and edge cases, then outline a two-pass algorithm for hint generation: first mark exact matches, then handle remaining letters with a frequency map to avoid overcounting. Discuss trade-offs between simplicity and efficiency, and mention how to structure the game loop to reject invalid words without consuming turns.
Pro tip: Explicitly call out the duplicate-letter edge case (e.g., target 'ABBE', guess 'BABY') and explain your frequency-map solution—this shows you anticipate tricky bugs. Also, mention that you'd write unit tests for hint generation before coding the game loop, demonstrating test-driven development.
Ask about dictionary size, case sensitivity, and how to handle duplicate letters. Confirm that invalid guesses don't count toward the 5 attempts.
Use a two-pass approach: first mark exact matches ('1') and decrement letter counts; then for remaining positions, mark '0' if the letter exists in the remaining count, else '-'.
Maintain a set of valid words for O(1) lookup. Loop until 5 valid guesses or correct guess, rejecting invalid words without incrementing the attempt counter.
Hint generation is O(n) per guess with O(1) extra space (fixed alphabet). Discuss alternative approaches like sorting or using arrays for counts.
Write test cases covering exact matches, wrong positions, absent letters, duplicates, and invalid words. Verify the game loop behavior.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.