FA-94689 / Exam timetabling constraints / Member archive

Conflict pairs counted in both orders and with themselves · case 04

The matrix contains reversed and self pairs.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

enrol rows [student, exam] (may repeat). For every unordered pair of distinct exams (a < b) count the students enrolled in both. Return [a, b, count] rows sorted, omitting zero counts.

Why this case matters

The conflict matrix is the input to every exam timetabling algorithm; count errors silently change weights.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
regression: pair loop bounds 1	[["BIO130", "BIO130", 1], ["BIO130", "ECON150", 1], ["BIO130", "MATH101H", 1], ["BIO130", "PHYS110", 1], ["CHEM120", "CHEM120", 2], ["CHEM120", "ECON150", 1], ["CHEM120", "HIST140", 1], ["ECON150", "BIO130", 1], ["ECON150", "CHEM120", 1], ["ECON150", "ECON150", 3], ["ECON150", "HIST140", 1], ["ECON150", "MATH101", 1], ["ECON150", "MATH101H", 1], ["ECON150", "PHYS110", 2], ["HIST140", "CHEM120", 1], ["HIST140", "ECON150", 1], ["HIST140", "HIST140", 3], ["HIST140", "MATH101", 2], ["HIST140", "PHYS110", 1], ["MATH101", "ECON150", 1], ["MATH101", "HIST140", 2], ["MATH101", "MATH101", 2], ["MATH101", "PHYS110", 1], ["MATH101H", "BIO130", 1], ["MATH101H", "ECON150", 1], ["MATH101H", "MATH101H", 1], ["MATH101H", "PHYS110", 1], ["PHYS110", "BIO130", 1], ["PHYS110", "ECON150", 2], ["PHYS110", "HIST140", 1], ["PHYS110", "MATH101", 1], ["PHYS110", "MATH101H", 1], ["PHYS110", "PHYS110", 2]]	`[["BIO130", "ECON150", 1], ["BIO130", "MATH101H", 1], ["BIO130", "PHYS110", 1], ["CHEM120", "ECON150", 1], ["CHEM120", "HIST140", 1], ["ECON150", "HIST140", 1], ["ECON150", "MATH101", 1], ["ECON150", "MATH101H", 1], ["ECON150", "PHYS110", 2], ["HIST140", "MATH101", 2], ["HIST140", "PHYS110", 1], ["MATH101", "PHYS110", 1], ["MATH101H", "PHYS110", 1]]`	Failed

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