Welcome! This repo is your starter code for Module 1.

You will implement:

• IntArrayToolkit (utility methods for int[])
• Student (validated data model)
• StudentArrayToolkit (sorting/searching over Student[])
• Main (small demo runner for your video)

✅ Autograding: Your score is based on passing the included JUnit tests (run locally with Maven, and on GitHub Actions).

All source files must start with:

package edu.sdccd.cisc191;

Your folder structure must match:

src/main/java/edu/sdccd/cisc191/

If your package or folder path differs, autograding will fail.

Implement:

• public static int sum(int[] a)
  • throws IllegalArgumentException if a is null
• public static int max(int[] a)
  • throws IllegalArgumentException if a is null or empty
• public static int indexOf(int[] a, int target)
  • returns index of first occurrence, or -1 if not found
  • throws IllegalArgumentException if a is null
• public static int[] copySortedAscending(int[] a)
  • returns a NEW sorted array (ascending)
  • must NOT modify original
  • throws IllegalArgumentException if a is null

Fields:

• name (String), gpa (double), id (int)

Constructor validation:

• name not null/blank
• gpa in [0.0, 4.0]
• id > 0
  Throw IllegalArgumentException if invalid.

Also include:

• getters
• toString() readable summary

Implement:

• public static Student[] copySortedByGpaDesc(Student[] students)
  • returns a NEW array sorted by GPA descending
  • ties: name ascending
  • must NOT modify original
• public static Student findByIdLinear(Student[] students, int id)
  • returns matching student or null
• public static Student[] topNByGpa(Student[] students, int n)
  • returns a NEW array of top N students by GPA desc (ties: name asc)
  • if n > length, return all
  • if n < 0, throw IllegalArgumentException

🪄 Lambda preview required: Sorting must use a Comparator created via lambda or method reference (no anonymous inner classes). (Note: this is graded primarily through peer review, not autograder.)

From terminal:

mvn test

In IntelliJ:

• Open the Maven tool window
• Run test

Show:

1. Your repo structure + correct package line
2. Running tests (green)
3. Running Main and explaining output

Answer these open-ended questions in your video:

• Q1: Where did you use defensive copying and why does it matter?
• Q2: Why can a method modify array contents passed into it?
• Q3: Why is a Comparator lambda useful for sorting objects?
• Q4: What bug did you hit (or avoid) and how did you debug it?

You will complete peer review via GitHub Pull Request:

• Make at least 2 meaningful improvements
• Leave at least 5 review comments
• PR description should explain what changed and why

✅ AI allowed for feedback-writing only (not for generating your partner’s solution code).

Submit your own work. Do not copy from other students or online sources. If you’re unsure whether something is allowed, ask first.