[R45-T013] Add reference-comparison checks for FairShareScheduling.addWeight - #52

Description

Adds JUnit reference-comparison regression tests for FairShareScheduling.User#addWeight(int) in src/main/java/com/thealgorithms/scheduling/FairShareScheduling.java, documents one representative result in the source Javadoc for addWeight(int), and adds a focused runner (work/R45-T013/check.py) that runs the tests and saves inputs, expected versus actual results, and tool versions. All existing behavior and public interfaces are preserved.

Related Issue

Fixes: #13

Type of Change

• Bug Fix
• New Feature
• UI/UX Improvement
• Performance Improvement
• Tests
• Documentation
• Refactoring / Maintenance
• CI/CD

Changes Made

• Added Javadoc on FairShareScheduling.User#addWeight(int) explaining one representative result (totalWeight = 0 -> addWeight(2) -> addWeight(3) -> totalWeight = 5; paired with a second user of weight 5 and totalResources = 100, allocateResources(100) assigns 50 to each user). No executable code or public API was altered.
• Added src/test/java/com/thealgorithms/scheduling/FairShareSchedulingReferenceTest.java with 4 test methods covering 36 logged comparisons:
  • Smallest valid inputs (weight = 0, weight = 1, and single-user totalResources = 1 → {"u1": 1}) with hand-calculated literal expected outputs and source-line citations.
  • Ordinary input (addWeight(2) then addWeight(3) → 5, paired with bob weight 5 and totalResources = 100 → {"alice": 50, "bob": 50}).
  • 24 enumerated small valid addWeight sequences and 6 multi-user FairShareScheduling allocation cases compared against both an explicit hand-calculated literal table and an independent IntStream / BigDecimal reference oracle.
  • Equivalent fresh inputs under controlled state, unregistered-user no-op guard (line 56), and defensive-copy verification of getAllocatedResources() (line 69).
• Added work/R45-T013/check.py (along with captured evidence in work/R45-T013/), which runs mvn test for FairShareSchedulingReferenceTest, verifies a nonzero test count and at least 20 comparisons, writes comparisons.txt, result.txt, mvn_output.txt, and tool_versions.txt, and exits non-zero on any failure.

Screenshots / Recordings

Not applicable (no UI changes).

Testing

Command: python3 work/R45-T013/check.py
(runs mvn -B test -Dtest=FairShareSchedulingReferenceTest -Dsurefire.failIfNoSpecifiedTests=false)

Result: tests=4 failures/errors=0 skipped=0 comparisons=36 mvn_exit=0, status=PASS

Existing suite: mvn -B test -Dtest=FairShareSchedulingTest -Dsurefire.failIfNoSpecifiedTests=false → Tests run: 4, Failures: 0, Errors: 0, Skipped: 0 (BUILD SUCCESS).

Negative check: temporarily changing this.totalWeight += weight; to this.totalWeight = weight; on line 40 made python3 work/R45-T013/check.py print status=FAIL (tests=4 failures/errors=3 skipped=0 mvn_exit=1) and exit non-zero; the temporary change was reverted and re-verified.

Style: mvn -B checkstyle:check reports 0 Checkstyle violations (BUILD SUCCESS).

Tool versions and comparison outputs are saved in work/R45-T013/tool_versions.txt and work/R45-T013/comparisons.txt.

Checklist

• I have tested my changes locally.
• I have added or updated tests, if needed.
• I have updated documentation, if needed.
• I have followed the project's coding guidelines.
• I have run the relevant tests and checks.
• I have addressed previous review feedback, if applicable.

Additional Notes

• There is no earlier review feedback to address.

• The work/R45-T013/ evidence folder is for coursework review only and should not go into any later upstream PR.

• I have read CONTRIBUTING.md.

• This pull request is all my own work -- I have not plagiarized it.

• All filenames are in PascalCase.

• All functions and variable names follow Java naming conventions.

• All new algorithms have a URL in their comments that points to Wikipedia or other similar explanations.

• All new algorithms include a corresponding test class that validates their functionality.

• All new code is formatted with clang-format -i --style=file path/to/your/file.java