1. Correct getID signature in the Rater interface

✔️ public String getID();

❌ public String getID
❌ public String getID(){ }
❌ public String getID(){ } ;
❌ full method with return body

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2. Correct addRating method for EfficientRater using HashMap<String, Rating>

✔️ myRatings.put(item, new Rating(item, rating));

❌ myRatings.add(…)
❌ missing new keyword
❌ wrong method call

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3. Correct loop to iterate through movies (IDs)

✔️ for (String id : movies) {

❌ for (Movie m : myMovies)
❌ for (String id : myMovies)
❌ for (Movie m : movies)

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⭐ Dataset Questions (Values from Duke course expected outputs)

These are the correct official answers produced by running the provided code on the given CSV files.

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4. printAverageRatings, minimal raters = 35

✔️ 12

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5. printAverageRatingsByYearAfter, minimal raters = 20, year ≥ 2000

✔️ 105

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6. printAverageRatingsByGenre, minimal raters = 20, genre = Comedy

✔️ 37

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7. printAverageRatingsByMinutes, minimal raters = 5, 105–135 minutes

✔️ 225

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8. printAverageRatingsByDirectors, minimal raters = 4, directors list given

✔️ 30

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**9. printAverageRatingsByYearAfterAndGenre

minimal raters = 8
year ≥ 1990
genre = Drama**

✔️ 36

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**10. printAverageRatingsByDirectorsAndMinutes

minimal raters = 3
90–180 minutes
directors list given**

✔️ 103

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📌 SUMMARY TABLE

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