Grade book

You are in a coding round. The interviewer wants a grade book that lives in memory. First, restate the ranking rule in one sentence and ask what a tie means. Then implement add, replace, and remove. Then implement top three. A student who has never been scored does not appear, and deleting the last score removes them. After it works, the interviewer adds a late score while you are reading the top three: explain whether the reader sees the old list or the new one, and what you would store if two graders wrote the same student at the same moment. Talk through the example before the code.