FA-94646 / Exam timetabling constraints / Open access

Conflict pair reported in booking order · case 01

The same conflict appears under different pair orders.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Exam pairs are not normalised.

VERIFIED REPAIR

Report the two exams in ascending id order.

Unsuccessful approach: Descending order is not the contract order.

Case contract

bookings [room, exam, start, end, setup minutes]; each booking occupies [start - setup, end + cleanup). Two bookings in the same room conflict if their occupied intervals overlap (touching is fine). Return sorted [room, exam, exam] rows with the exam pair sorted.

Why this case matters

Exam rooms need setup and clearance time; conflicts must account for both buffers.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(bookings, cleanup):
    by = {}
    for r, ex, s, e, setup in bookings:
        by.setdefault(r, []).append((s - setup, e + cleanup, ex))
    out = []
    for r in sorted(by):
        bs = by[r]
        for i in range(len(bs)):
            for j in range(i + 1, len(bs)):
                a, b = bs[i], bs[j]
                if a[0] < b[1] and b[0] < a[1]:
                    out.append([r, a[2], b[2]])
    return sorted(out)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: pair normalisation 1', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15],
   [['R1', 'A', 'B']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 720, 810, 30], ['R2', 'CS', 540, 630, 30]], 15],
   [['R2', 'GEO', 'PHYS']]),
  ('partial repair guard 3',
   [[['R1', 'ART', 600, 660, 45], ['R1', 'GEO', 840, 930, 15], ['R2', 'MED', 840, 900, 30],
     ['R1', 'LAW', 600, 720, 0]],
    15],
   [['R1', 'ART', 'LAW']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('normal control 5',
   [[['R2', 'PHYS', 840, 930, 45], ['R1', 'ART', 780, 870, 15], ['R1', 'CS', 840, 960, 0]], 15],
   [['R1', 'ART', 'CS']]),
  ('normal control 6',
   [[['R2', 'GEO', 600, 720, 45], ['R2', 'LAW', 660, 780, 45], ['R1', 'ART', 780, 900, 45]], 10],
   [['R2', 'GEO', 'LAW']]),
  ('normal control 7',
   [[['R1', 'ENG', 660, 720, 15], ['R2', 'GEO', 720, 780, 15], ['R2', 'MED', 780, 870, 45]], 15],
   [['R2', 'GEO', 'MED']]),
  ('normal control 8',
   [[['R2', 'ART', 720, 780, 45], ['R1', 'LAW', 660, 750, 0], ['R1', 'CS', 720, 840, 0],
     ['R1', 'MED', 720, 810, 45]],
    30],
   [['R1', 'CS', 'LAW'], ['R1', 'CS', 'MED'], ['R1', 'LAW', 'MED']])],
 [('regression: pair normalisation 1', [[['R1', 'B', 540, 600, 45], ['R1', 'A', 610, 700, 0]], 15],
   [['R1', 'A', 'B']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'PHYS', 540, 630, 0], ['R1', 'CS', 600, 720, 45], ['R2', 'ENG', 600, 720, 0]], 30],
   [['R2', 'ENG', 'PHYS']]),
  ('partial repair guard 3',
   [[['R2', 'GEO', 720, 780, 45], ['R1', 'MED', 660, 720, 30], ['R2', 'CS', 780, 840, 15],
     ['R2', 'LAW', 780, 900, 30]],
    10],
   [['R2', 'CS', 'GEO'], ['R2', 'CS', 'LAW'], ['R2', 'GEO', 'LAW']]),
  ('boundary control 4', [[['R1', 'A', 540, 600, 30], ['R1', 'B', 645, 700, 30]], 15], []),
  ('normal control 5', [[['R2', 'PHYS', 720, 780, 30], ['R2', 'GEO', 600, 690, 0]], 30],
   [['R2', 'GEO', 'PHYS']]),
  ('normal control 6',
   [[['R2', 'GEO', 540, 630, 0], ['R1', 'ART', 660, 780, 45], ['R2', 'PHYS', 840, 900, 0],
     ['R1', 'ENG', 720, 780, 0]],
    30],
   [['R1', 'ART', 'ENG']]),
  ('normal control 7',
   [[['R2', 'CS', 540, 630, 45], ['R1', 'LAW', 600, 660, 45], ['R2', 'MED', 540, 600, 0],
     ['R2', 'ENG', 780, 900, 30]],
    15],
   [['R2', 'CS', 'MED']]),
  ('normal control 8',
   [[['R2', 'GEO', 840, 900, 15], ['R1', 'MED', 780, 900, 30], ['R1', 'CS', 540, 630, 15],
     ['R2', 'ENG', 540, 600, 45], ['R2', 'ART', 840, 900, 15]],
    30],
   [['R2', 'ART', 'GEO']])],
 [('regression: pair normalisation 1',
   [[['R1', 'ENG', 660, 750, 15], ['R2', 'LAW', 660, 750, 0], ['R2', 'PHYS', 780, 900, 0],
     ['R1', 'ART', 540, 660, 15]],
    10],
   [['R1', 'ART', 'ENG']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'ART', 540, 660, 0], ['R1', 'PHYS', 660, 720, 0], ['R1', 'ENG', 600, 720, 30],
     ['R2', 'GEO', 540, 600, 30]],
    15],
   [['R1', 'ENG', 'PHYS'], ['R2', 'ART', 'GEO']]),
  ('partial repair guard 3',
   [[['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 720, 810, 30], ['R2', 'CS', 540, 630, 30]], 15],
   [['R2', 'GEO', 'PHYS']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15], [['R1', 'A', 'B']]),
  ('normal control 6',
   [[['R2', 'LAW', 780, 900, 15], ['R2', 'CS', 540, 630, 15], ['R1', 'GEO', 840, 960, 45],
     ['R1', 'ART', 780, 840, 45]],
    10],
   [['R1', 'ART', 'GEO']]),
  ('normal control 7',
   [[['R1', 'ART', 660, 750, 45], ['R1', 'CS', 840, 900, 30], ['R2', 'ENG', 540, 600, 30],
     ['R2', 'GEO', 600, 660, 45], ['R2', 'LAW', 540, 630, 45]],
    15],
   [['R2', 'ENG', 'GEO'], ['R2', 'ENG', 'LAW'], ['R2', 'GEO', 'LAW']]),
  ('normal control 8',
   [[['R1', 'CS', 780, 900, 15], ['R2', 'ENG', 720, 780, 15], ['R2', 'GEO', 600, 660, 45],
     ['R2', 'MED', 600, 720, 15], ['R1', 'PHYS', 600, 690, 30]],
    10],
   [['R2', 'ENG', 'MED'], ['R2', 'GEO', 'MED']])],
 [('regression: pair normalisation 1',
   [[['R2', 'CS', 840, 930, 15], ['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 660, 720, 15],
     ['R1', 'ENG', 780, 900, 45], ['R2', 'LAW', 840, 900, 30]],
    15],
   [['R2', 'CS', 'LAW'], ['R2', 'GEO', 'PHYS']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'GEO', 540, 600, 45], ['R2', 'ENG', 660, 780, 15], ['R1', 'PHYS', 780, 870, 0],
     ['R2', 'CS', 600, 660, 0], ['R1', 'ART', 660, 750, 30]],
    30],
   [['R2', 'CS', 'ENG'], ['R2', 'CS', 'GEO']]),
  ('partial repair guard 3',
   [[['R1', 'GEO', 540, 600, 45], ['R1', 'MED', 540, 600, 45], ['R2', 'LAW', 780, 900, 45]], 30],
   [['R1', 'GEO', 'MED']]),
  ('boundary control 4', [[['R1', 'A', 540, 600, 30], ['R1', 'B', 645, 700, 30]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 600, 45], ['R1', 'A', 610, 700, 0]], 15], [['R1', 'A', 'B']]),
  ('normal control 6',
   [[['R1', 'PHYS', 840, 930, 0], ['R2', 'ENG', 600, 720, 30], ['R2', 'CS', 600, 720, 15]], 15],
   [['R2', 'CS', 'ENG']]),
  ('normal control 7',
   [[['R2', 'GEO', 720, 840, 0], ['R1', 'LAW', 840, 930, 0], ['R2', 'PHYS', 540, 660, 0],
     ['R1', 'ART', 540, 630, 30]],
    15],
   []),
  ('normal control 8',
   [[['R2', 'CS', 840, 900, 30], ['R1', 'LAW', 840, 960, 30], ['R2', 'ART', 660, 780, 45]], 10], [])],
 [('regression: pair normalisation 1',
   [[['R1', 'CS', 840, 960, 0], ['R2', 'PHYS', 540, 600, 45], ['R2', 'GEO', 720, 780, 0],
     ['R2', 'ART', 600, 690, 0], ['R2', 'MED', 720, 810, 15]],
    10],
   [['R2', 'ART', 'PHYS'], ['R2', 'GEO', 'MED']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'ART', 840, 900, 30], ['R1', 'ENG', 840, 900, 0], ['R2', 'PHYS', 840, 930, 0],
     ['R1', 'MED', 540, 630, 30], ['R2', 'LAW', 840, 900, 15]],
    10],
   [['R2', 'ART', 'LAW'], ['R2', 'ART', 'PHYS'], ['R2', 'LAW', 'PHYS']]),
  ('partial repair guard 3',
   [[['R2', 'ART', 660, 720, 45], ['R2', 'PHYS', 720, 840, 30], ['R1', 'ENG', 840, 930, 0],
     ['R1', 'GEO', 780, 900, 0], ['R1', 'CS', 720, 780, 45]],
    10],
   [['R1', 'CS', 'GEO'], ['R1', 'ENG', 'GEO'], ['R2', 'ART', 'PHYS']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15], [['R1', 'A', 'B']]),
  ('normal control 6', [[['R2', 'MED', 540, 630, 0], ['R1', 'GEO', 660, 750, 45]], 15], []),
  ('normal control 7',
   [[['R2', 'ENG', 720, 810, 15], ['R2', 'CS', 780, 900, 0], ['R2', 'GEO', 540, 630, 45],
     ['R1', 'PHYS', 600, 660, 30], ['R1', 'LAW', 600, 720, 0]],
    30],
   [['R1', 'LAW', 'PHYS'], ['R2', 'CS', 'ENG']]),
  ('normal control 8', [[['R1', 'LAW', 600, 660, 30], ['R1', 'PHYS', 600, 660, 45]], 30],
   [['R1', 'LAW', 'PHYS']])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
regression: pair normalisation 1	`[['R1', 'B', 'A']]`	`[['R1', 'A', 'B']]`	Failed
regression variant: pair normalisation 2	`[['R2', 'PHYS', 'GEO']]`	`[['R2', 'GEO', 'PHYS']]`	Failed
partial repair guard 3	`[['R1', 'ART', 'LAW']]`	`[['R1', 'ART', 'LAW']]`	Passed
boundary control 4	`[]`	`[]`	Passed
normal control 5	`[['R1', 'ART', 'CS']]`	`[['R1', 'ART', 'CS']]`	Passed
normal control 6	`[['R2', 'GEO', 'LAW']]`	`[['R2', 'GEO', 'LAW']]`	Passed
normal control 7	`[['R2', 'GEO', 'MED']]`	`[['R2', 'GEO', 'MED']]`	Passed
normal control 8	`[['R1', 'CS', 'MED'], ['R1', 'LAW', 'CS'], ['R1', 'LAW', 'MED']]`	`[['R1', 'CS', 'LAW'], ['R1', 'CS', 'MED'], ['R1', 'LAW', 'MED']]`	Failed

SHA-256 / a3a5c34d8489b00cd2efc827fb5b78e40ba40f36622fb24976b552684e334a31

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(bookings, cleanup):
    by = {}
    for r, ex, s, e, setup in bookings:
        by.setdefault(r, []).append((s - setup, e + cleanup, ex))
    out = []
    for r in sorted(by):
        bs = by[r]
        for i in range(len(bs)):
            for j in range(i + 1, len(bs)):
                a, b = bs[i], bs[j]
                if a[0] < b[1] and b[0] < a[1]:
                    out.append([r] + sorted([a[2], b[2]], reverse=True))
    return sorted(out)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: pair normalisation 1', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15],
   [['R1', 'A', 'B']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 720, 810, 30], ['R2', 'CS', 540, 630, 30]], 15],
   [['R2', 'GEO', 'PHYS']]),
  ('partial repair guard 3',
   [[['R1', 'ART', 600, 660, 45], ['R1', 'GEO', 840, 930, 15], ['R2', 'MED', 840, 900, 30],
     ['R1', 'LAW', 600, 720, 0]],
    15],
   [['R1', 'ART', 'LAW']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('normal control 5',
   [[['R2', 'PHYS', 840, 930, 45], ['R1', 'ART', 780, 870, 15], ['R1', 'CS', 840, 960, 0]], 15],
   [['R1', 'ART', 'CS']]),
  ('normal control 6',
   [[['R2', 'GEO', 600, 720, 45], ['R2', 'LAW', 660, 780, 45], ['R1', 'ART', 780, 900, 45]], 10],
   [['R2', 'GEO', 'LAW']]),
  ('normal control 7',
   [[['R1', 'ENG', 660, 720, 15], ['R2', 'GEO', 720, 780, 15], ['R2', 'MED', 780, 870, 45]], 15],
   [['R2', 'GEO', 'MED']]),
  ('normal control 8',
   [[['R2', 'ART', 720, 780, 45], ['R1', 'LAW', 660, 750, 0], ['R1', 'CS', 720, 840, 0],
     ['R1', 'MED', 720, 810, 45]],
    30],
   [['R1', 'CS', 'LAW'], ['R1', 'CS', 'MED'], ['R1', 'LAW', 'MED']])],
 [('regression: pair normalisation 1', [[['R1', 'B', 540, 600, 45], ['R1', 'A', 610, 700, 0]], 15],
   [['R1', 'A', 'B']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'PHYS', 540, 630, 0], ['R1', 'CS', 600, 720, 45], ['R2', 'ENG', 600, 720, 0]], 30],
   [['R2', 'ENG', 'PHYS']]),
  ('partial repair guard 3',
   [[['R2', 'GEO', 720, 780, 45], ['R1', 'MED', 660, 720, 30], ['R2', 'CS', 780, 840, 15],
     ['R2', 'LAW', 780, 900, 30]],
    10],
   [['R2', 'CS', 'GEO'], ['R2', 'CS', 'LAW'], ['R2', 'GEO', 'LAW']]),
  ('boundary control 4', [[['R1', 'A', 540, 600, 30], ['R1', 'B', 645, 700, 30]], 15], []),
  ('normal control 5', [[['R2', 'PHYS', 720, 780, 30], ['R2', 'GEO', 600, 690, 0]], 30],
   [['R2', 'GEO', 'PHYS']]),
  ('normal control 6',
   [[['R2', 'GEO', 540, 630, 0], ['R1', 'ART', 660, 780, 45], ['R2', 'PHYS', 840, 900, 0],
     ['R1', 'ENG', 720, 780, 0]],
    30],
   [['R1', 'ART', 'ENG']]),
  ('normal control 7',
   [[['R2', 'CS', 540, 630, 45], ['R1', 'LAW', 600, 660, 45], ['R2', 'MED', 540, 600, 0],
     ['R2', 'ENG', 780, 900, 30]],
    15],
   [['R2', 'CS', 'MED']]),
  ('normal control 8',
   [[['R2', 'GEO', 840, 900, 15], ['R1', 'MED', 780, 900, 30], ['R1', 'CS', 540, 630, 15],
     ['R2', 'ENG', 540, 600, 45], ['R2', 'ART', 840, 900, 15]],
    30],
   [['R2', 'ART', 'GEO']])],
 [('regression: pair normalisation 1',
   [[['R1', 'ENG', 660, 750, 15], ['R2', 'LAW', 660, 750, 0], ['R2', 'PHYS', 780, 900, 0],
     ['R1', 'ART', 540, 660, 15]],
    10],
   [['R1', 'ART', 'ENG']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'ART', 540, 660, 0], ['R1', 'PHYS', 660, 720, 0], ['R1', 'ENG', 600, 720, 30],
     ['R2', 'GEO', 540, 600, 30]],
    15],
   [['R1', 'ENG', 'PHYS'], ['R2', 'ART', 'GEO']]),
  ('partial repair guard 3',
   [[['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 720, 810, 30], ['R2', 'CS', 540, 630, 30]], 15],
   [['R2', 'GEO', 'PHYS']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15], [['R1', 'A', 'B']]),
  ('normal control 6',
   [[['R2', 'LAW', 780, 900, 15], ['R2', 'CS', 540, 630, 15], ['R1', 'GEO', 840, 960, 45],
     ['R1', 'ART', 780, 840, 45]],
    10],
   [['R1', 'ART', 'GEO']]),
  ('normal control 7',
   [[['R1', 'ART', 660, 750, 45], ['R1', 'CS', 840, 900, 30], ['R2', 'ENG', 540, 600, 30],
     ['R2', 'GEO', 600, 660, 45], ['R2', 'LAW', 540, 630, 45]],
    15],
   [['R2', 'ENG', 'GEO'], ['R2', 'ENG', 'LAW'], ['R2', 'GEO', 'LAW']]),
  ('normal control 8',
   [[['R1', 'CS', 780, 900, 15], ['R2', 'ENG', 720, 780, 15], ['R2', 'GEO', 600, 660, 45],
     ['R2', 'MED', 600, 720, 15], ['R1', 'PHYS', 600, 690, 30]],
    10],
   [['R2', 'ENG', 'MED'], ['R2', 'GEO', 'MED']])],
 [('regression: pair normalisation 1',
   [[['R2', 'CS', 840, 930, 15], ['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 660, 720, 15],
     ['R1', 'ENG', 780, 900, 45], ['R2', 'LAW', 840, 900, 30]],
    15],
   [['R2', 'CS', 'LAW'], ['R2', 'GEO', 'PHYS']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'GEO', 540, 600, 45], ['R2', 'ENG', 660, 780, 15], ['R1', 'PHYS', 780, 870, 0],
     ['R2', 'CS', 600, 660, 0], ['R1', 'ART', 660, 750, 30]],
    30],
   [['R2', 'CS', 'ENG'], ['R2', 'CS', 'GEO']]),
  ('partial repair guard 3',
   [[['R1', 'GEO', 540, 600, 45], ['R1', 'MED', 540, 600, 45], ['R2', 'LAW', 780, 900, 45]], 30],
   [['R1', 'GEO', 'MED']]),
  ('boundary control 4', [[['R1', 'A', 540, 600, 30], ['R1', 'B', 645, 700, 30]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 600, 45], ['R1', 'A', 610, 700, 0]], 15], [['R1', 'A', 'B']]),
  ('normal control 6',
   [[['R1', 'PHYS', 840, 930, 0], ['R2', 'ENG', 600, 720, 30], ['R2', 'CS', 600, 720, 15]], 15],
   [['R2', 'CS', 'ENG']]),
  ('normal control 7',
   [[['R2', 'GEO', 720, 840, 0], ['R1', 'LAW', 840, 930, 0], ['R2', 'PHYS', 540, 660, 0],
     ['R1', 'ART', 540, 630, 30]],
    15],
   []),
  ('normal control 8',
   [[['R2', 'CS', 840, 900, 30], ['R1', 'LAW', 840, 960, 30], ['R2', 'ART', 660, 780, 45]], 10], [])],
 [('regression: pair normalisation 1',
   [[['R1', 'CS', 840, 960, 0], ['R2', 'PHYS', 540, 600, 45], ['R2', 'GEO', 720, 780, 0],
     ['R2', 'ART', 600, 690, 0], ['R2', 'MED', 720, 810, 15]],
    10],
   [['R2', 'ART', 'PHYS'], ['R2', 'GEO', 'MED']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'ART', 840, 900, 30], ['R1', 'ENG', 840, 900, 0], ['R2', 'PHYS', 840, 930, 0],
     ['R1', 'MED', 540, 630, 30], ['R2', 'LAW', 840, 900, 15]],
    10],
   [['R2', 'ART', 'LAW'], ['R2', 'ART', 'PHYS'], ['R2', 'LAW', 'PHYS']]),
  ('partial repair guard 3',
   [[['R2', 'ART', 660, 720, 45], ['R2', 'PHYS', 720, 840, 30], ['R1', 'ENG', 840, 930, 0],
     ['R1', 'GEO', 780, 900, 0], ['R1', 'CS', 720, 780, 45]],
    10],
   [['R1', 'CS', 'GEO'], ['R1', 'ENG', 'GEO'], ['R2', 'ART', 'PHYS']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15], [['R1', 'A', 'B']]),
  ('normal control 6', [[['R2', 'MED', 540, 630, 0], ['R1', 'GEO', 660, 750, 45]], 15], []),
  ('normal control 7',
   [[['R2', 'ENG', 720, 810, 15], ['R2', 'CS', 780, 900, 0], ['R2', 'GEO', 540, 630, 45],
     ['R1', 'PHYS', 600, 660, 30], ['R1', 'LAW', 600, 720, 0]],
    30],
   [['R1', 'LAW', 'PHYS'], ['R2', 'CS', 'ENG']]),
  ('normal control 8', [[['R1', 'LAW', 600, 660, 30], ['R1', 'PHYS', 600, 660, 45]], 30],
   [['R1', 'LAW', 'PHYS']])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
regression: pair normalisation 1	`[['R1', 'B', 'A']]`	`[['R1', 'A', 'B']]`	Failed
regression variant: pair normalisation 2	`[['R2', 'PHYS', 'GEO']]`	`[['R2', 'GEO', 'PHYS']]`	Failed
partial repair guard 3	`[['R1', 'LAW', 'ART']]`	`[['R1', 'ART', 'LAW']]`	Failed
boundary control 4	`[]`	`[]`	Passed
normal control 5	`[['R1', 'CS', 'ART']]`	`[['R1', 'ART', 'CS']]`	Failed
normal control 6	`[['R2', 'LAW', 'GEO']]`	`[['R2', 'GEO', 'LAW']]`	Failed
normal control 7	`[['R2', 'MED', 'GEO']]`	`[['R2', 'GEO', 'MED']]`	Failed
normal control 8	`[['R1', 'LAW', 'CS'], ['R1', 'MED', 'CS'], ['R1', 'MED', 'LAW']]`	`[['R1', 'CS', 'LAW'], ['R1', 'CS', 'MED'], ['R1', 'LAW', 'MED']]`	Failed

SHA-256 / 01bb8734cb40b3110e70d1a1b95f91bea979448fd2b2af8ece37b3e51b90749a

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(bookings, cleanup):
    by = {}
    for r, ex, s, e, setup in bookings:
        by.setdefault(r, []).append((s - setup, e + cleanup, ex))
    out = []
    for r in sorted(by):
        bs = by[r]
        for i in range(len(bs)):
            for j in range(i + 1, len(bs)):
                a, b = bs[i], bs[j]
                if a[0] < b[1] and b[0] < a[1]:
                    out.append([r] + sorted([a[2], b[2]]))
    return sorted(out)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: pair normalisation 1', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15],
   [['R1', 'A', 'B']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 720, 810, 30], ['R2', 'CS', 540, 630, 30]], 15],
   [['R2', 'GEO', 'PHYS']]),
  ('partial repair guard 3',
   [[['R1', 'ART', 600, 660, 45], ['R1', 'GEO', 840, 930, 15], ['R2', 'MED', 840, 900, 30],
     ['R1', 'LAW', 600, 720, 0]],
    15],
   [['R1', 'ART', 'LAW']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('normal control 5',
   [[['R2', 'PHYS', 840, 930, 45], ['R1', 'ART', 780, 870, 15], ['R1', 'CS', 840, 960, 0]], 15],
   [['R1', 'ART', 'CS']]),
  ('normal control 6',
   [[['R2', 'GEO', 600, 720, 45], ['R2', 'LAW', 660, 780, 45], ['R1', 'ART', 780, 900, 45]], 10],
   [['R2', 'GEO', 'LAW']]),
  ('normal control 7',
   [[['R1', 'ENG', 660, 720, 15], ['R2', 'GEO', 720, 780, 15], ['R2', 'MED', 780, 870, 45]], 15],
   [['R2', 'GEO', 'MED']]),
  ('normal control 8',
   [[['R2', 'ART', 720, 780, 45], ['R1', 'LAW', 660, 750, 0], ['R1', 'CS', 720, 840, 0],
     ['R1', 'MED', 720, 810, 45]],
    30],
   [['R1', 'CS', 'LAW'], ['R1', 'CS', 'MED'], ['R1', 'LAW', 'MED']])],
 [('regression: pair normalisation 1', [[['R1', 'B', 540, 600, 45], ['R1', 'A', 610, 700, 0]], 15],
   [['R1', 'A', 'B']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'PHYS', 540, 630, 0], ['R1', 'CS', 600, 720, 45], ['R2', 'ENG', 600, 720, 0]], 30],
   [['R2', 'ENG', 'PHYS']]),
  ('partial repair guard 3',
   [[['R2', 'GEO', 720, 780, 45], ['R1', 'MED', 660, 720, 30], ['R2', 'CS', 780, 840, 15],
     ['R2', 'LAW', 780, 900, 30]],
    10],
   [['R2', 'CS', 'GEO'], ['R2', 'CS', 'LAW'], ['R2', 'GEO', 'LAW']]),
  ('boundary control 4', [[['R1', 'A', 540, 600, 30], ['R1', 'B', 645, 700, 30]], 15], []),
  ('normal control 5', [[['R2', 'PHYS', 720, 780, 30], ['R2', 'GEO', 600, 690, 0]], 30],
   [['R2', 'GEO', 'PHYS']]),
  ('normal control 6',
   [[['R2', 'GEO', 540, 630, 0], ['R1', 'ART', 660, 780, 45], ['R2', 'PHYS', 840, 900, 0],
     ['R1', 'ENG', 720, 780, 0]],
    30],
   [['R1', 'ART', 'ENG']]),
  ('normal control 7',
   [[['R2', 'CS', 540, 630, 45], ['R1', 'LAW', 600, 660, 45], ['R2', 'MED', 540, 600, 0],
     ['R2', 'ENG', 780, 900, 30]],
    15],
   [['R2', 'CS', 'MED']]),
  ('normal control 8',
   [[['R2', 'GEO', 840, 900, 15], ['R1', 'MED', 780, 900, 30], ['R1', 'CS', 540, 630, 15],
     ['R2', 'ENG', 540, 600, 45], ['R2', 'ART', 840, 900, 15]],
    30],
   [['R2', 'ART', 'GEO']])],
 [('regression: pair normalisation 1',
   [[['R1', 'ENG', 660, 750, 15], ['R2', 'LAW', 660, 750, 0], ['R2', 'PHYS', 780, 900, 0],
     ['R1', 'ART', 540, 660, 15]],
    10],
   [['R1', 'ART', 'ENG']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'ART', 540, 660, 0], ['R1', 'PHYS', 660, 720, 0], ['R1', 'ENG', 600, 720, 30],
     ['R2', 'GEO', 540, 600, 30]],
    15],
   [['R1', 'ENG', 'PHYS'], ['R2', 'ART', 'GEO']]),
  ('partial repair guard 3',
   [[['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 720, 810, 30], ['R2', 'CS', 540, 630, 30]], 15],
   [['R2', 'GEO', 'PHYS']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15], [['R1', 'A', 'B']]),
  ('normal control 6',
   [[['R2', 'LAW', 780, 900, 15], ['R2', 'CS', 540, 630, 15], ['R1', 'GEO', 840, 960, 45],
     ['R1', 'ART', 780, 840, 45]],
    10],
   [['R1', 'ART', 'GEO']]),
  ('normal control 7',
   [[['R1', 'ART', 660, 750, 45], ['R1', 'CS', 840, 900, 30], ['R2', 'ENG', 540, 600, 30],
     ['R2', 'GEO', 600, 660, 45], ['R2', 'LAW', 540, 630, 45]],
    15],
   [['R2', 'ENG', 'GEO'], ['R2', 'ENG', 'LAW'], ['R2', 'GEO', 'LAW']]),
  ('normal control 8',
   [[['R1', 'CS', 780, 900, 15], ['R2', 'ENG', 720, 780, 15], ['R2', 'GEO', 600, 660, 45],
     ['R2', 'MED', 600, 720, 15], ['R1', 'PHYS', 600, 690, 30]],
    10],
   [['R2', 'ENG', 'MED'], ['R2', 'GEO', 'MED']])],
 [('regression: pair normalisation 1',
   [[['R2', 'CS', 840, 930, 15], ['R2', 'PHYS', 720, 780, 15], ['R2', 'GEO', 660, 720, 15],
     ['R1', 'ENG', 780, 900, 45], ['R2', 'LAW', 840, 900, 30]],
    15],
   [['R2', 'CS', 'LAW'], ['R2', 'GEO', 'PHYS']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'GEO', 540, 600, 45], ['R2', 'ENG', 660, 780, 15], ['R1', 'PHYS', 780, 870, 0],
     ['R2', 'CS', 600, 660, 0], ['R1', 'ART', 660, 750, 30]],
    30],
   [['R2', 'CS', 'ENG'], ['R2', 'CS', 'GEO']]),
  ('partial repair guard 3',
   [[['R1', 'GEO', 540, 600, 45], ['R1', 'MED', 540, 600, 45], ['R2', 'LAW', 780, 900, 45]], 30],
   [['R1', 'GEO', 'MED']]),
  ('boundary control 4', [[['R1', 'A', 540, 600, 30], ['R1', 'B', 645, 700, 30]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 600, 45], ['R1', 'A', 610, 700, 0]], 15], [['R1', 'A', 'B']]),
  ('normal control 6',
   [[['R1', 'PHYS', 840, 930, 0], ['R2', 'ENG', 600, 720, 30], ['R2', 'CS', 600, 720, 15]], 15],
   [['R2', 'CS', 'ENG']]),
  ('normal control 7',
   [[['R2', 'GEO', 720, 840, 0], ['R1', 'LAW', 840, 930, 0], ['R2', 'PHYS', 540, 660, 0],
     ['R1', 'ART', 540, 630, 30]],
    15],
   []),
  ('normal control 8',
   [[['R2', 'CS', 840, 900, 30], ['R1', 'LAW', 840, 960, 30], ['R2', 'ART', 660, 780, 45]], 10], [])],
 [('regression: pair normalisation 1',
   [[['R1', 'CS', 840, 960, 0], ['R2', 'PHYS', 540, 600, 45], ['R2', 'GEO', 720, 780, 0],
     ['R2', 'ART', 600, 690, 0], ['R2', 'MED', 720, 810, 15]],
    10],
   [['R2', 'ART', 'PHYS'], ['R2', 'GEO', 'MED']]),
  ('regression variant: pair normalisation 2',
   [[['R2', 'ART', 840, 900, 30], ['R1', 'ENG', 840, 900, 0], ['R2', 'PHYS', 840, 930, 0],
     ['R1', 'MED', 540, 630, 30], ['R2', 'LAW', 840, 900, 15]],
    10],
   [['R2', 'ART', 'LAW'], ['R2', 'ART', 'PHYS'], ['R2', 'LAW', 'PHYS']]),
  ('partial repair guard 3',
   [[['R2', 'ART', 660, 720, 45], ['R2', 'PHYS', 720, 840, 30], ['R1', 'ENG', 840, 930, 0],
     ['R1', 'GEO', 780, 900, 0], ['R1', 'CS', 720, 780, 45]],
    10],
   [['R1', 'CS', 'GEO'], ['R1', 'ENG', 'GEO'], ['R2', 'ART', 'PHYS']]),
  ('boundary control 4', [[['R1', 'B', 540, 600, 15], ['R2', 'A', 540, 600, 15]], 15], []),
  ('boundary control 5', [[['R1', 'B', 540, 700, 15], ['R1', 'A', 600, 620, 15]], 15], [['R1', 'A', 'B']]),
  ('normal control 6', [[['R2', 'MED', 540, 630, 0], ['R1', 'GEO', 660, 750, 45]], 15], []),
  ('normal control 7',
   [[['R2', 'ENG', 720, 810, 15], ['R2', 'CS', 780, 900, 0], ['R2', 'GEO', 540, 630, 45],
     ['R1', 'PHYS', 600, 660, 30], ['R1', 'LAW', 600, 720, 0]],
    30],
   [['R1', 'LAW', 'PHYS'], ['R2', 'CS', 'ENG']]),
  ('normal control 8', [[['R1', 'LAW', 600, 660, 30], ['R1', 'PHYS', 600, 660, 45]], 30],
   [['R1', 'LAW', 'PHYS']])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
regression: pair normalisation 1	`[['R1', 'A', 'B']]`	`[['R1', 'A', 'B']]`	Passed
regression variant: pair normalisation 2	`[['R2', 'GEO', 'PHYS']]`	`[['R2', 'GEO', 'PHYS']]`	Passed
partial repair guard 3	`[['R1', 'ART', 'LAW']]`	`[['R1', 'ART', 'LAW']]`	Passed
boundary control 4	`[]`	`[]`	Passed
normal control 5	`[['R1', 'ART', 'CS']]`	`[['R1', 'ART', 'CS']]`	Passed
normal control 6	`[['R2', 'GEO', 'LAW']]`	`[['R2', 'GEO', 'LAW']]`	Passed
normal control 7	`[['R2', 'GEO', 'MED']]`	`[['R2', 'GEO', 'MED']]`	Passed
normal control 8	`[['R1', 'CS', 'LAW'], ['R1', 'CS', 'MED'], ['R1', 'LAW', 'MED']]`	`[['R1', 'CS', 'LAW'], ['R1', 'CS', 'MED'], ['R1', 'LAW', 'MED']]`	Passed

SHA-256 / 2e6615ce329b54ace6961a62ca3f079d58d0fdd40be080ce05f5bf8975863f1f

Verification & scope

Stipulated toy exam-timetabling rule set for a bounded model; it does not claim conformance with any institution's regulations or a benchmark specification, and it performs no search or optimisation. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:52:06.301730+00:00.

Case digest / 3c89635407f165e97fcf652b49e37ce5fcd9d443eb05bf31847241a3e80336d5