FA-94432 / Exam timetabling constraints / Member archive

Proximity cost normalised by enrolment rows · case 02

The reported per-student cost shrinks as students take more exams.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

enrol [student, exam] rows (may repeat) and exam periods. For each student, each pair of distinct exams d = 1..5 periods apart costs 2^(5-d). Return [total, number of students, total/students as a reduced fraction string].

Why this case matters

The Carter proximity cost is the standard exam-timetabling quality measure; each piece has a known implementation pitfall.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: normaliser 1	`[1, 2, "1/2"]`	`[1, 1, "1"]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.