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  IT6003 - Advanced Java Programming
  Homework 1: Collections Framework & Generics
  State University of Zanzibar (SUZA)
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  Total Marks: 40
  Due: As announced by instructor
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INSTRUCTIONS:
- Submit .java files in a ZIP named RegNo_HW1.zip
- Include comments explaining your logic
- You may be asked to explain your code during viva

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Problem 1: Student Registry System [10 marks]
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Create a student registration system using multiple collection types:

a) Create a Student class with: regNo (String), name (String),
   department (String), gpa (double), courses (List<String>).
   Override equals(), hashCode() (based on regNo), and toString().
   Implement Comparable<Student> (sort by name). [2 marks]

b) Use HashMap<String, Student> to store students by regNo.
   Implement: addStudent(), removeStudent(), findByRegNo().
   Ensure no duplicate regNo. [2 marks]

c) Use TreeSet<Student> to maintain students sorted by name.
   Print all students in alphabetical order. [1 mark]

d) Use HashMap<String, Set<String>> to map each department to
   a set of student regNos. Implement:
   - addToDepartment(String dept, String regNo)
   - getStudentsInDept(String dept) -> List<Student> sorted by GPA
   [3 marks]

e) Generate a report showing:
   - Total students per department
   - Highest and lowest GPA per department
   - Dean's list (GPA >= 3.5) sorted by GPA descending
   [2 marks]


Problem 2: Generic Data Structures [10 marks]
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a) Implement a generic class CircularQueue<T> with:
   - Constructor: CircularQueue(int capacity)
   - void enqueue(T item) - throws RuntimeException if full
   - T dequeue() - throws RuntimeException if empty
   - T peek()
   - boolean isFull(), boolean isEmpty()
   - int size()
   - String toString() showing all elements
   Use a generic array internally (T[] with casting).
   [5 marks]

b) Implement a generic interface Filterable<T>:
   List<T> filter(List<T> items, Predicate<T> condition);
   List<T> reject(List<T> items, Predicate<T> condition);
   T findFirst(List<T> items, Predicate<T> condition);
   long count(List<T> items, Predicate<T> condition);

   Create a class DataProcessor<T> implementing Filterable<T>.
   Test with List<Integer>, List<String>, List<Student>.
   [5 marks]


Problem 3: Nested Collections Challenge [10 marks]
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Build a University Timetable system:

Data structure: Map<String, Map<String, List<String>>>
Outer key: Day of week (Monday-Friday)
Inner key: Time slot ("08:00-10:00", "10:00-12:00", "14:00-16:00")
Value: List of course codes scheduled at that time

a) Populate the timetable with at least 15 courses across the week. [2 marks]

b) Implement these query methods: [8 marks]
   - List<String> getCoursesOnDay(String day)
   - List<String> getCoursesAtTime(String timeSlot) // across all days
   - boolean hasConflict(String day, String timeSlot) // more than 3 courses
   - String findFreeSlots(String day) // time slots with no courses
   - Map<String, Integer> courseCountPerDay() // how many courses each day
   - String busiestDay() // day with most courses
   - void printFormattedTimetable() // nicely formatted table output


Problem 4: Iterator Implementation [10 marks]
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a) Implement a generic class FilteredIterator<T> that wraps an
   Iterator<T> and only returns elements matching a Predicate<T>.
   Implement Iterator<T> interface (hasNext, next, remove). [5 marks]

b) Implement a generic class MergedIterator<T> that takes two
   sorted Iterator<T> objects (elements implement Comparable<T>)
   and iterates through both in sorted order (merge operation).
   [5 marks]

Test both with sample data and print results.

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Viva Questions (be prepared):
1. What is the time complexity of HashMap.get() vs TreeMap.get()?
2. When would you use LinkedHashMap over HashMap?
3. Explain type erasure in generics.
4. Can you create a generic array in Java? Why or why not?
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