FA-94616 / Exam timetabling constraints / Open access

Overlapping sittings on one campus not reported · case 01

A student booked into two overlapping exams in the same building passes.

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

ROOT CAUSE

Shortfalls are only checked between different campuses.

VERIFIED REPAIR

A negative gap is a shortfall even on the same campus.

Unsuccessful approach: Making the comparison inclusive still skips same-campus overlaps and adds zero-shortfall rows.

Case contract

sits [student, exam, start, end], campus exam -> campus, travel "X|Y" -> minutes stored in either order. For each student's consecutive sittings by start, the needed gap is the travel time between different campuses (0 for the same campus); if the gap from previous end to next start is smaller, report [student, previous exam, next exam, shortfall].

Why this case matters

Multi-campus exam timetables must leave travel time between a student's consecutive sittings.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(sits, campus, travel):
    by = {}
    for st, ex, s, e in sits:
        by.setdefault(st, []).append((s, e, ex))
    out = []
    for st in sorted(by):
        seq = sorted(by[st])
        for (s1, e1, x1), (s2, e2, x2) in zip(seq, seq[1:]):
            gap = s2 - e1
            c1, c2 = campus[x1], campus[x2]
            need = 0
            if c1 != c2:
                need = travel.get(c1 + '|' + c2, travel.get(c2 + '|' + c1, 0))
            if gap < need and c1 != c2:
                out.append([st, x1, x2, need - gap])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: same campus overlap 1',
   [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('regression variant: same campus overlap 2',
   [[['s5', 'MATH101H', 540, 600], ['s5', 'CHEM120', 780, 870], ['s5', 'BIO130', 645, 765],
     ['s4', 'CHEM120', 810, 930], ['s2', 'BIO130', 540, 660], ['s4', 'BIO130', 540, 660],
     ['s2', 'ECON150', 675, 765], ['s4', 'PHYS110', 930, 1050], ['s4', 'MATH101', 720, 840]],
    {'MATH101': 'north',
     'MATH101H': 'north',
     'PHYS110': 'city',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'BIO130', 'ECON150', 45], ['s4', 'MATH101', 'CHEM120', 30], ['s4', 'CHEM120', 'PHYS110', 60],
    ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]),
  ('partial repair guard 3',
   [[['s1', 'ECON150', 600, 720], ['s4', 'PHYS110', 600, 720], ['s4', 'BIO130', 765, 825],
     ['s4', 'CHEM120', 854, 974], ['s1', 'MATH101', 540, 630], ['s4', 'MATH101H', 989, 1109]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s1', 'MATH101', 'ECON150', 90], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]),
  ('boundary control 4',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('normal control 6',
   [[['s2', 'MATH101', 719, 839], ['s5', 'MATH101', 720, 840], ['s2', 'MATH101H', 600, 690],
     ['s5', 'HIST140', 600, 690]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   []),
  ('normal control 7',
   [[['s1', 'MATH101', 810, 900], ['s5', 'ECON150', 690, 780], ['s4', 'CHEM120', 540, 630],
     ['s4', 'BIO130', 660, 720], ['s4', 'PHYS110', 749, 839], ['s1', 'HIST140', 540, 630],
     ['s5', 'CHEM120', 600, 720], ['s1', 'MATH101H', 675, 765], ['s4', 'HIST140', 839, 959]],
    {'MATH101': 'north',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 60}],
   [['s5', 'CHEM120', 'ECON150', 30]]),
  ('normal control 8',
   [[['s5', 'MATH101H', 675, 795], ['s5', 'HIST140', 765, 885], ['s5', 'MATH101', 540, 660]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 30}],
   [['s5', 'MATH101H', 'HIST140', 60]])],
 [('regression: same campus overlap 1',
   [[['s4', 'MATH101', 630, 720], ['s2', 'PHYS110', 615, 675], ['s2', 'MATH101H', 645, 765],
     ['s4', 'MATH101H', 540, 600], ['s4', 'BIO130', 751, 841], ['s2', 'CHEM120', 825, 945],
     ['s2', 'MATH101', 540, 600]],
    {'MATH101': 'south',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'MATH101', 'PHYS110', 15], ['s2', 'PHYS110', 'MATH101H', 30]]),
  ('regression variant: same campus overlap 2',
   [[['s1', 'PHYS110', 825, 915], ['s1', 'HIST140', 946, 1066], ['s2', 'CHEM120', 600, 690],
     ['s4', 'ECON150', 570, 660], ['s4', 'HIST140', 705, 825], ['s2', 'HIST140', 780, 840],
     ['s1', 'CHEM120', 600, 720], ['s1', 'MATH101', 765, 825], ['s2', 'MATH101', 660, 780],
     ['s4', 'MATH101H', 540, 600]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'MATH101', 'PHYS110', 30], ['s2', 'CHEM120', 'MATH101', 30], ['s4', 'MATH101H', 'ECON150', 30]]),
  ('partial repair guard 3',
   [[['s3', 'ECON150', 780, 840], ['s4', 'MATH101H', 600, 720], ['s3', 'HIST140', 600, 720],
     ['s4', 'HIST140', 1050, 1110], ['s4', 'CHEM120', 870, 990], ['s4', 'BIO130', 780, 900],
     ['s2', 'HIST140', 705, 795], ['s2', 'CHEM120', 600, 690]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'city',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s2', 'CHEM120', 'HIST140', 15], ['s4', 'BIO130', 'CHEM120', 30]]),
  ('boundary control 4', [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('boundary control 5',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('normal control 6',
   [[['s4', 'ECON150', 600, 660], ['s2', 'PHYS110', 690, 780], ['s4', 'MATH101H', 675, 765],
     ['s4', 'MATH101', 780, 840], ['s2', 'CHEM120', 540, 660], ['s4', 'BIO130', 840, 960]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s4', 'ECON150', 'MATH101H', 15], ['s4', 'MATH101', 'BIO130', 30]]),
  ('normal control 7',
   [[['s2', 'CHEM120', 1035, 1095], ['s2', 'PHYS110', 600, 720], ['s2', 'ECON150', 945, 1035],
     ['s2', 'HIST140', 810, 930]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 60}],
   []),
  ('normal control 8',
   [[['s3', 'PHYS110', 825, 885], ['s3', 'BIO130', 675, 735], ['s3', 'CHEM120', 540, 660],
     ['s3', 'HIST140', 945, 1035]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'city',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s3', 'CHEM120', 'BIO130', 45]])],
 [('regression: same campus overlap 1',
   [[['s2', 'PHYS110', 751, 841], ['s2', 'BIO130', 841, 901], ['s2', 'CHEM120', 600, 660],
     ['s1', 'PHYS110', 885, 975], ['s1', 'ECON150', 705, 795], ['s2', 'ECON150', 691, 781],
     ['s1', 'BIO130', 540, 660], ['s1', 'HIST140', 945, 1035]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'PHYS110', 'HIST140', 30], ['s2', 'ECON150', 'PHYS110', 60]]),
  ('regression variant: same campus overlap 2',
   [[['s3', 'CHEM120', 915, 1035], ['s4', 'MATH101H', 690, 780], ['s2', 'HIST140', 690, 750],
     ['s3', 'ECON150', 600, 720], ['s4', 'BIO130', 540, 600], ['s2', 'MATH101', 540, 660],
     ['s2', 'BIO130', 839, 959], ['s3', 'MATH101', 840, 900], ['s4', 'MATH101', 570, 630],
     ['s3', 'BIO130', 720, 810], ['s2', 'CHEM120', 779, 869]],
    {'MATH101': 'city',
     'MATH101H': 'north',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'MATH101', 'HIST140', 30], ['s2', 'HIST140', 'CHEM120', 16], ['s2', 'CHEM120', 'BIO130', 30],
    ['s4', 'BIO130', 'MATH101', 30]]),
  ('partial repair guard 3',
   [[['s2', 'CHEM120', 720, 810], ['s3', 'PHYS110', 735, 855], ['s1', 'MATH101', 1036, 1126],
     ['s1', 'CHEM120', 885, 1005], ['s1', 'MATH101H', 765, 885], ['s1', 'BIO130', 600, 720],
     ['s3', 'BIO130', 600, 690], ['s2', 'PHYS110', 825, 915], ['s3', 'CHEM120', 885, 975],
     ['s2', 'MATH101H', 540, 630]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'CHEM120', 'PHYS110', 45], ['s3', 'PHYS110', 'CHEM120', 30]]),
  ('boundary control 4',
   [[['s1', 'A', 540, 600], ['s1', 'B', 629, 700]], {'A': 'south', 'B': 'north'}, {'north|south': 30}],
   [['s1', 'A', 'B', 1]]),
  ('boundary control 5', [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('normal control 6',
   [[['s2', 'PHYS110', 600, 690], ['s3', 'MATH101H', 600, 660], ['s3', 'PHYS110', 691, 781],
     ['s3', 'BIO130', 1021, 1111], ['s3', 'MATH101', 841, 931], ['s2', 'ECON150', 660, 720]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'PHYS110', 'ECON150', 75]]),
  ('normal control 7',
   [[['s3', 'PHYS110', 750, 870], ['s2', 'MATH101H', 930, 1050], ['s2', 'CHEM120', 675, 735],
     ['s3', 'ECON150', 600, 720], ['s3', 'CHEM120', 900, 1020], ['s2', 'HIST140', 750, 840],
     ['s2', 'BIO130', 540, 630]],
    {'MATH101': 'city',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s3', 'ECON150', 'PHYS110', 30]]),
  ('normal control 8',
   [[['s2', 'ECON150', 600, 660], ['s2', 'PHYS110', 630, 690]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'ECON150', 'PHYS110', 30]])],
 [('regression: same campus overlap 1',
   [[['s3', 'PHYS110', 600, 690], ['s4', 'PHYS110', 660, 720], ['s4', 'BIO130', 900, 990],
     ['s3', 'HIST140', 750, 870], ['s3', 'CHEM120', 690, 780], ['s4', 'MATH101H', 780, 840],
     ['s3', 'MATH101', 660, 720], ['s4', 'CHEM120', 600, 660]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 60}],
   [['s3', 'PHYS110', 'MATH101', 30], ['s3', 'MATH101', 'CHEM120', 90], ['s3', 'CHEM120', 'HIST140', 30],
    ['s4', 'CHEM120', 'PHYS110', 60]]),
  ('regression variant: same campus overlap 2',
   [[['s5', 'HIST140', 780, 900], ['s4', 'BIO130', 690, 780], ['s5', 'MATH101H', 540, 600],
     ['s3', 'CHEM120', 645, 705], ['s5', 'PHYS110', 900, 1020], ['s3', 'HIST140', 540, 600],
     ['s4', 'ECON150', 600, 720], ['s5', 'CHEM120', 690, 810]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s4', 'ECON150', 'BIO130', 30], ['s5', 'CHEM120', 'HIST140', 30], ['s5', 'HIST140', 'PHYS110', 45]]),
  ('partial repair guard 3',
   [[['s3', 'HIST140', 540, 660], ['s5', 'PHYS110', 750, 870], ['s5', 'BIO130', 1019, 1079],
     ['s3', 'MATH101H', 900, 1020], ['s5', 'ECON150', 600, 690], ['s5', 'CHEM120', 930, 990],
     ['s3', 'CHEM120', 720, 840]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s5', 'CHEM120', 'BIO130', 1]]),
  ('boundary control 4',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 629, 700]], {'A': 'south', 'B': 'north'}, {'north|south': 30}],
   [['s1', 'A', 'B', 1]]),
  ('normal control 6',
   [[['s5', 'BIO130', 540, 630], ['s2', 'MATH101H', 720, 810], ['s2', 'MATH101', 600, 660],
     ['s5', 'ECON150', 600, 690]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'city',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 30}],
   [['s5', 'BIO130', 'ECON150', 30]]),
  ('normal control 7',
   [[['s4', 'ECON150', 990, 1080], ['s5', 'CHEM120', 540, 600], ['s5', 'ECON150', 690, 810],
     ['s5', 'MATH101H', 1080, 1140], ['s5', 'PHYS110', 870, 990], ['s4', 'MATH101H', 1050, 1110],
     ['s4', 'BIO130', 810, 930], ['s4', 'MATH101', 600, 720]],
    {'MATH101': 'north',
     'MATH101H': 'north',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   [['s4', 'ECON150', 'MATH101H', 60]]),
  ('normal control 8',
   [[['s2', 'MATH101H', 600, 720], ['s4', 'PHYS110', 675, 795], ['s4', 'MATH101H', 825, 915],
     ['s1', 'BIO130', 540, 630], ['s4', 'MATH101', 885, 1005], ['s2', 'PHYS110', 780, 840],
     ['s1', 'PHYS110', 659, 719], ['s4', 'ECON150', 540, 630]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'BIO130', 'PHYS110', 1], ['s4', 'MATH101H', 'MATH101', 30]])],
 [('regression: same campus overlap 1',
   [[['s1', 'MATH101H', 751, 811], ['s2', 'MATH101', 540, 630], ['s1', 'MATH101', 826, 946],
     ['s2', 'HIST140', 749, 869], ['s2', 'PHYS110', 659, 779], ['s1', 'BIO130', 600, 720],
     ['s1', 'CHEM120', 961, 1021]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 30}],
   [['s1', 'MATH101', 'CHEM120', 15], ['s2', 'MATH101', 'PHYS110', 1], ['s2', 'PHYS110', 'HIST140', 30]]),
  ('regression variant: same campus overlap 2',
   [[['s1', 'PHYS110', 690, 750], ['s1', 'ECON150', 600, 690], ['s1', 'MATH101H', 660, 720]],
    {'MATH101': 'south',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 30, 'city|north': 60}],
   [['s1', 'ECON150', 'MATH101H', 60], ['s1', 'MATH101H', 'PHYS110', 30]]),
  ('partial repair guard 3',
   [[['s3', 'MATH101', 705, 825], ['s4', 'PHYS110', 660, 780], ['s4', 'MATH101', 989, 1049],
     ['s4', 'CHEM120', 600, 660], ['s3', 'PHYS110', 840, 960], ['s4', 'HIST140', 809, 929],
     ['s3', 'BIO130', 540, 660]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 30}],
   []),
  ('boundary control 4',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('normal control 6',
   [[['s1', 'HIST140', 705, 765], ['s1', 'ECON150', 825, 915], ['s1', 'PHYS110', 915, 975],
     ['s1', 'BIO130', 540, 660]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   []),
  ('normal control 7',
   [[['s2', 'HIST140', 720, 840], ['s5', 'PHYS110', 750, 840], ['s1', 'PHYS110', 600, 660],
     ['s5', 'BIO130', 600, 720], ['s1', 'MATH101', 675, 765], ['s2', 'PHYS110', 540, 630],
     ['s1', 'BIO130', 796, 856]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 30}],
   []),
  ('normal control 8',
   [[['s4', 'PHYS110', 720, 780], ['s4', 'MATH101', 1020, 1110], ['s5', 'ECON150', 931, 1051],
     ['s4', 'MATH101H', 600, 720], ['s5', 'HIST140', 600, 720], ['s1', 'PHYS110', 720, 810],
     ['s5', 'MATH101H', 780, 900], ['s4', 'CHEM120', 840, 960], ['s1', 'BIO130', 600, 720]],
    {'MATH101': 'north',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s5', 'MATH101H', 'ECON150', 14]])]]
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: same campus overlap 1	`[]`	`[['s1', 'A', 'B', 10]]`	Failed
regression variant: same campus overlap 2	`[['s2', 'BIO130', 'ECON150', 45], ['s4', 'CHEM120', 'PHYS110', 60], ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]`	`[['s2', 'BIO130', 'ECON150', 45], ['s4', 'MATH101', 'CHEM120', 30], ['s4', 'CHEM120', 'PHYS110', 60], ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]`	Failed
partial repair guard 3	`[['s1', 'MATH101', 'ECON150', 90], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]`	`[['s1', 'MATH101', 'ECON150', 90], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]`	Passed
boundary control 4	`[]`	`[]`	Passed
boundary control 5	`[]`	`[]`	Passed
normal control 6	`[]`	`[]`	Passed
normal control 7	`[]`	`[['s5', 'CHEM120', 'ECON150', 30]]`	Failed
normal control 8	`[['s5', 'MATH101H', 'HIST140', 60]]`	`[['s5', 'MATH101H', 'HIST140', 60]]`	Passed

SHA-256 / 91043687e45258a705ade71c5afcc943077a0b4d29294907970ffebe7e2f0ebd

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(sits, campus, travel):
    by = {}
    for st, ex, s, e in sits:
        by.setdefault(st, []).append((s, e, ex))
    out = []
    for st in sorted(by):
        seq = sorted(by[st])
        for (s1, e1, x1), (s2, e2, x2) in zip(seq, seq[1:]):
            gap = s2 - e1
            c1, c2 = campus[x1], campus[x2]
            need = 0
            if c1 != c2:
                need = travel.get(c1 + '|' + c2, travel.get(c2 + '|' + c1, 0))
            if gap <= need and c1 != c2:
                out.append([st, x1, x2, need - gap])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: same campus overlap 1',
   [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('regression variant: same campus overlap 2',
   [[['s5', 'MATH101H', 540, 600], ['s5', 'CHEM120', 780, 870], ['s5', 'BIO130', 645, 765],
     ['s4', 'CHEM120', 810, 930], ['s2', 'BIO130', 540, 660], ['s4', 'BIO130', 540, 660],
     ['s2', 'ECON150', 675, 765], ['s4', 'PHYS110', 930, 1050], ['s4', 'MATH101', 720, 840]],
    {'MATH101': 'north',
     'MATH101H': 'north',
     'PHYS110': 'city',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'BIO130', 'ECON150', 45], ['s4', 'MATH101', 'CHEM120', 30], ['s4', 'CHEM120', 'PHYS110', 60],
    ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]),
  ('partial repair guard 3',
   [[['s1', 'ECON150', 600, 720], ['s4', 'PHYS110', 600, 720], ['s4', 'BIO130', 765, 825],
     ['s4', 'CHEM120', 854, 974], ['s1', 'MATH101', 540, 630], ['s4', 'MATH101H', 989, 1109]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s1', 'MATH101', 'ECON150', 90], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]),
  ('boundary control 4',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('normal control 6',
   [[['s2', 'MATH101', 719, 839], ['s5', 'MATH101', 720, 840], ['s2', 'MATH101H', 600, 690],
     ['s5', 'HIST140', 600, 690]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   []),
  ('normal control 7',
   [[['s1', 'MATH101', 810, 900], ['s5', 'ECON150', 690, 780], ['s4', 'CHEM120', 540, 630],
     ['s4', 'BIO130', 660, 720], ['s4', 'PHYS110', 749, 839], ['s1', 'HIST140', 540, 630],
     ['s5', 'CHEM120', 600, 720], ['s1', 'MATH101H', 675, 765], ['s4', 'HIST140', 839, 959]],
    {'MATH101': 'north',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 60}],
   [['s5', 'CHEM120', 'ECON150', 30]]),
  ('normal control 8',
   [[['s5', 'MATH101H', 675, 795], ['s5', 'HIST140', 765, 885], ['s5', 'MATH101', 540, 660]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 30}],
   [['s5', 'MATH101H', 'HIST140', 60]])],
 [('regression: same campus overlap 1',
   [[['s4', 'MATH101', 630, 720], ['s2', 'PHYS110', 615, 675], ['s2', 'MATH101H', 645, 765],
     ['s4', 'MATH101H', 540, 600], ['s4', 'BIO130', 751, 841], ['s2', 'CHEM120', 825, 945],
     ['s2', 'MATH101', 540, 600]],
    {'MATH101': 'south',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'MATH101', 'PHYS110', 15], ['s2', 'PHYS110', 'MATH101H', 30]]),
  ('regression variant: same campus overlap 2',
   [[['s1', 'PHYS110', 825, 915], ['s1', 'HIST140', 946, 1066], ['s2', 'CHEM120', 600, 690],
     ['s4', 'ECON150', 570, 660], ['s4', 'HIST140', 705, 825], ['s2', 'HIST140', 780, 840],
     ['s1', 'CHEM120', 600, 720], ['s1', 'MATH101', 765, 825], ['s2', 'MATH101', 660, 780],
     ['s4', 'MATH101H', 540, 600]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'MATH101', 'PHYS110', 30], ['s2', 'CHEM120', 'MATH101', 30], ['s4', 'MATH101H', 'ECON150', 30]]),
  ('partial repair guard 3',
   [[['s3', 'ECON150', 780, 840], ['s4', 'MATH101H', 600, 720], ['s3', 'HIST140', 600, 720],
     ['s4', 'HIST140', 1050, 1110], ['s4', 'CHEM120', 870, 990], ['s4', 'BIO130', 780, 900],
     ['s2', 'HIST140', 705, 795], ['s2', 'CHEM120', 600, 690]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'city',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s2', 'CHEM120', 'HIST140', 15], ['s4', 'BIO130', 'CHEM120', 30]]),
  ('boundary control 4', [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('boundary control 5',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('normal control 6',
   [[['s4', 'ECON150', 600, 660], ['s2', 'PHYS110', 690, 780], ['s4', 'MATH101H', 675, 765],
     ['s4', 'MATH101', 780, 840], ['s2', 'CHEM120', 540, 660], ['s4', 'BIO130', 840, 960]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s4', 'ECON150', 'MATH101H', 15], ['s4', 'MATH101', 'BIO130', 30]]),
  ('normal control 7',
   [[['s2', 'CHEM120', 1035, 1095], ['s2', 'PHYS110', 600, 720], ['s2', 'ECON150', 945, 1035],
     ['s2', 'HIST140', 810, 930]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 60}],
   []),
  ('normal control 8',
   [[['s3', 'PHYS110', 825, 885], ['s3', 'BIO130', 675, 735], ['s3', 'CHEM120', 540, 660],
     ['s3', 'HIST140', 945, 1035]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'city',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s3', 'CHEM120', 'BIO130', 45]])],
 [('regression: same campus overlap 1',
   [[['s2', 'PHYS110', 751, 841], ['s2', 'BIO130', 841, 901], ['s2', 'CHEM120', 600, 660],
     ['s1', 'PHYS110', 885, 975], ['s1', 'ECON150', 705, 795], ['s2', 'ECON150', 691, 781],
     ['s1', 'BIO130', 540, 660], ['s1', 'HIST140', 945, 1035]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'PHYS110', 'HIST140', 30], ['s2', 'ECON150', 'PHYS110', 60]]),
  ('regression variant: same campus overlap 2',
   [[['s3', 'CHEM120', 915, 1035], ['s4', 'MATH101H', 690, 780], ['s2', 'HIST140', 690, 750],
     ['s3', 'ECON150', 600, 720], ['s4', 'BIO130', 540, 600], ['s2', 'MATH101', 540, 660],
     ['s2', 'BIO130', 839, 959], ['s3', 'MATH101', 840, 900], ['s4', 'MATH101', 570, 630],
     ['s3', 'BIO130', 720, 810], ['s2', 'CHEM120', 779, 869]],
    {'MATH101': 'city',
     'MATH101H': 'north',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'MATH101', 'HIST140', 30], ['s2', 'HIST140', 'CHEM120', 16], ['s2', 'CHEM120', 'BIO130', 30],
    ['s4', 'BIO130', 'MATH101', 30]]),
  ('partial repair guard 3',
   [[['s2', 'CHEM120', 720, 810], ['s3', 'PHYS110', 735, 855], ['s1', 'MATH101', 1036, 1126],
     ['s1', 'CHEM120', 885, 1005], ['s1', 'MATH101H', 765, 885], ['s1', 'BIO130', 600, 720],
     ['s3', 'BIO130', 600, 690], ['s2', 'PHYS110', 825, 915], ['s3', 'CHEM120', 885, 975],
     ['s2', 'MATH101H', 540, 630]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'CHEM120', 'PHYS110', 45], ['s3', 'PHYS110', 'CHEM120', 30]]),
  ('boundary control 4',
   [[['s1', 'A', 540, 600], ['s1', 'B', 629, 700]], {'A': 'south', 'B': 'north'}, {'north|south': 30}],
   [['s1', 'A', 'B', 1]]),
  ('boundary control 5', [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('normal control 6',
   [[['s2', 'PHYS110', 600, 690], ['s3', 'MATH101H', 600, 660], ['s3', 'PHYS110', 691, 781],
     ['s3', 'BIO130', 1021, 1111], ['s3', 'MATH101', 841, 931], ['s2', 'ECON150', 660, 720]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'PHYS110', 'ECON150', 75]]),
  ('normal control 7',
   [[['s3', 'PHYS110', 750, 870], ['s2', 'MATH101H', 930, 1050], ['s2', 'CHEM120', 675, 735],
     ['s3', 'ECON150', 600, 720], ['s3', 'CHEM120', 900, 1020], ['s2', 'HIST140', 750, 840],
     ['s2', 'BIO130', 540, 630]],
    {'MATH101': 'city',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s3', 'ECON150', 'PHYS110', 30]]),
  ('normal control 8',
   [[['s2', 'ECON150', 600, 660], ['s2', 'PHYS110', 630, 690]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'ECON150', 'PHYS110', 30]])],
 [('regression: same campus overlap 1',
   [[['s3', 'PHYS110', 600, 690], ['s4', 'PHYS110', 660, 720], ['s4', 'BIO130', 900, 990],
     ['s3', 'HIST140', 750, 870], ['s3', 'CHEM120', 690, 780], ['s4', 'MATH101H', 780, 840],
     ['s3', 'MATH101', 660, 720], ['s4', 'CHEM120', 600, 660]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 60}],
   [['s3', 'PHYS110', 'MATH101', 30], ['s3', 'MATH101', 'CHEM120', 90], ['s3', 'CHEM120', 'HIST140', 30],
    ['s4', 'CHEM120', 'PHYS110', 60]]),
  ('regression variant: same campus overlap 2',
   [[['s5', 'HIST140', 780, 900], ['s4', 'BIO130', 690, 780], ['s5', 'MATH101H', 540, 600],
     ['s3', 'CHEM120', 645, 705], ['s5', 'PHYS110', 900, 1020], ['s3', 'HIST140', 540, 600],
     ['s4', 'ECON150', 600, 720], ['s5', 'CHEM120', 690, 810]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s4', 'ECON150', 'BIO130', 30], ['s5', 'CHEM120', 'HIST140', 30], ['s5', 'HIST140', 'PHYS110', 45]]),
  ('partial repair guard 3',
   [[['s3', 'HIST140', 540, 660], ['s5', 'PHYS110', 750, 870], ['s5', 'BIO130', 1019, 1079],
     ['s3', 'MATH101H', 900, 1020], ['s5', 'ECON150', 600, 690], ['s5', 'CHEM120', 930, 990],
     ['s3', 'CHEM120', 720, 840]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s5', 'CHEM120', 'BIO130', 1]]),
  ('boundary control 4',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 629, 700]], {'A': 'south', 'B': 'north'}, {'north|south': 30}],
   [['s1', 'A', 'B', 1]]),
  ('normal control 6',
   [[['s5', 'BIO130', 540, 630], ['s2', 'MATH101H', 720, 810], ['s2', 'MATH101', 600, 660],
     ['s5', 'ECON150', 600, 690]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'city',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 30}],
   [['s5', 'BIO130', 'ECON150', 30]]),
  ('normal control 7',
   [[['s4', 'ECON150', 990, 1080], ['s5', 'CHEM120', 540, 600], ['s5', 'ECON150', 690, 810],
     ['s5', 'MATH101H', 1080, 1140], ['s5', 'PHYS110', 870, 990], ['s4', 'MATH101H', 1050, 1110],
     ['s4', 'BIO130', 810, 930], ['s4', 'MATH101', 600, 720]],
    {'MATH101': 'north',
     'MATH101H': 'north',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   [['s4', 'ECON150', 'MATH101H', 60]]),
  ('normal control 8',
   [[['s2', 'MATH101H', 600, 720], ['s4', 'PHYS110', 675, 795], ['s4', 'MATH101H', 825, 915],
     ['s1', 'BIO130', 540, 630], ['s4', 'MATH101', 885, 1005], ['s2', 'PHYS110', 780, 840],
     ['s1', 'PHYS110', 659, 719], ['s4', 'ECON150', 540, 630]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'BIO130', 'PHYS110', 1], ['s4', 'MATH101H', 'MATH101', 30]])],
 [('regression: same campus overlap 1',
   [[['s1', 'MATH101H', 751, 811], ['s2', 'MATH101', 540, 630], ['s1', 'MATH101', 826, 946],
     ['s2', 'HIST140', 749, 869], ['s2', 'PHYS110', 659, 779], ['s1', 'BIO130', 600, 720],
     ['s1', 'CHEM120', 961, 1021]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 30}],
   [['s1', 'MATH101', 'CHEM120', 15], ['s2', 'MATH101', 'PHYS110', 1], ['s2', 'PHYS110', 'HIST140', 30]]),
  ('regression variant: same campus overlap 2',
   [[['s1', 'PHYS110', 690, 750], ['s1', 'ECON150', 600, 690], ['s1', 'MATH101H', 660, 720]],
    {'MATH101': 'south',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 30, 'city|north': 60}],
   [['s1', 'ECON150', 'MATH101H', 60], ['s1', 'MATH101H', 'PHYS110', 30]]),
  ('partial repair guard 3',
   [[['s3', 'MATH101', 705, 825], ['s4', 'PHYS110', 660, 780], ['s4', 'MATH101', 989, 1049],
     ['s4', 'CHEM120', 600, 660], ['s3', 'PHYS110', 840, 960], ['s4', 'HIST140', 809, 929],
     ['s3', 'BIO130', 540, 660]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 30}],
   []),
  ('boundary control 4',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('normal control 6',
   [[['s1', 'HIST140', 705, 765], ['s1', 'ECON150', 825, 915], ['s1', 'PHYS110', 915, 975],
     ['s1', 'BIO130', 540, 660]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   []),
  ('normal control 7',
   [[['s2', 'HIST140', 720, 840], ['s5', 'PHYS110', 750, 840], ['s1', 'PHYS110', 600, 660],
     ['s5', 'BIO130', 600, 720], ['s1', 'MATH101', 675, 765], ['s2', 'PHYS110', 540, 630],
     ['s1', 'BIO130', 796, 856]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 30}],
   []),
  ('normal control 8',
   [[['s4', 'PHYS110', 720, 780], ['s4', 'MATH101', 1020, 1110], ['s5', 'ECON150', 931, 1051],
     ['s4', 'MATH101H', 600, 720], ['s5', 'HIST140', 600, 720], ['s1', 'PHYS110', 720, 810],
     ['s5', 'MATH101H', 780, 900], ['s4', 'CHEM120', 840, 960], ['s1', 'BIO130', 600, 720]],
    {'MATH101': 'north',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s5', 'MATH101H', 'ECON150', 14]])]]
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: same campus overlap 1	`[]`	`[['s1', 'A', 'B', 10]]`	Failed
regression variant: same campus overlap 2	`[['s2', 'BIO130', 'ECON150', 45], ['s4', 'BIO130', 'MATH101', 0], ['s4', 'CHEM120', 'PHYS110', 60], ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]`	`[['s2', 'BIO130', 'ECON150', 45], ['s4', 'MATH101', 'CHEM120', 30], ['s4', 'CHEM120', 'PHYS110', 60], ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]`	Failed
partial repair guard 3	`[['s1', 'MATH101', 'ECON150', 90], ['s4', 'PHYS110', 'BIO130', 0], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]`	`[['s1', 'MATH101', 'ECON150', 90], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]`	Failed
boundary control 4	`[]`	`[]`	Passed
boundary control 5	`[['s1', 'A', 'B', 0]]`	`[]`	Failed
normal control 6	`[]`	`[]`	Passed
normal control 7	`[['s1', 'MATH101H', 'MATH101', 0]]`	`[['s5', 'CHEM120', 'ECON150', 30]]`	Failed
normal control 8	`[['s5', 'MATH101H', 'HIST140', 60]]`	`[['s5', 'MATH101H', 'HIST140', 60]]`	Passed

SHA-256 / 386fd94a8153aa8017b6f493ccef7ebdf86e6ee3607d70a6095db4a27bd6f75d

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(sits, campus, travel):
    by = {}
    for st, ex, s, e in sits:
        by.setdefault(st, []).append((s, e, ex))
    out = []
    for st in sorted(by):
        seq = sorted(by[st])
        for (s1, e1, x1), (s2, e2, x2) in zip(seq, seq[1:]):
            gap = s2 - e1
            c1, c2 = campus[x1], campus[x2]
            need = 0
            if c1 != c2:
                need = travel.get(c1 + '|' + c2, travel.get(c2 + '|' + c1, 0))
            if gap < need:
                out.append([st, x1, x2, need - gap])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: same campus overlap 1',
   [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('regression variant: same campus overlap 2',
   [[['s5', 'MATH101H', 540, 600], ['s5', 'CHEM120', 780, 870], ['s5', 'BIO130', 645, 765],
     ['s4', 'CHEM120', 810, 930], ['s2', 'BIO130', 540, 660], ['s4', 'BIO130', 540, 660],
     ['s2', 'ECON150', 675, 765], ['s4', 'PHYS110', 930, 1050], ['s4', 'MATH101', 720, 840]],
    {'MATH101': 'north',
     'MATH101H': 'north',
     'PHYS110': 'city',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'BIO130', 'ECON150', 45], ['s4', 'MATH101', 'CHEM120', 30], ['s4', 'CHEM120', 'PHYS110', 60],
    ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]),
  ('partial repair guard 3',
   [[['s1', 'ECON150', 600, 720], ['s4', 'PHYS110', 600, 720], ['s4', 'BIO130', 765, 825],
     ['s4', 'CHEM120', 854, 974], ['s1', 'MATH101', 540, 630], ['s4', 'MATH101H', 989, 1109]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s1', 'MATH101', 'ECON150', 90], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]),
  ('boundary control 4',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('normal control 6',
   [[['s2', 'MATH101', 719, 839], ['s5', 'MATH101', 720, 840], ['s2', 'MATH101H', 600, 690],
     ['s5', 'HIST140', 600, 690]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   []),
  ('normal control 7',
   [[['s1', 'MATH101', 810, 900], ['s5', 'ECON150', 690, 780], ['s4', 'CHEM120', 540, 630],
     ['s4', 'BIO130', 660, 720], ['s4', 'PHYS110', 749, 839], ['s1', 'HIST140', 540, 630],
     ['s5', 'CHEM120', 600, 720], ['s1', 'MATH101H', 675, 765], ['s4', 'HIST140', 839, 959]],
    {'MATH101': 'north',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 60}],
   [['s5', 'CHEM120', 'ECON150', 30]]),
  ('normal control 8',
   [[['s5', 'MATH101H', 675, 795], ['s5', 'HIST140', 765, 885], ['s5', 'MATH101', 540, 660]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 30}],
   [['s5', 'MATH101H', 'HIST140', 60]])],
 [('regression: same campus overlap 1',
   [[['s4', 'MATH101', 630, 720], ['s2', 'PHYS110', 615, 675], ['s2', 'MATH101H', 645, 765],
     ['s4', 'MATH101H', 540, 600], ['s4', 'BIO130', 751, 841], ['s2', 'CHEM120', 825, 945],
     ['s2', 'MATH101', 540, 600]],
    {'MATH101': 'south',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'MATH101', 'PHYS110', 15], ['s2', 'PHYS110', 'MATH101H', 30]]),
  ('regression variant: same campus overlap 2',
   [[['s1', 'PHYS110', 825, 915], ['s1', 'HIST140', 946, 1066], ['s2', 'CHEM120', 600, 690],
     ['s4', 'ECON150', 570, 660], ['s4', 'HIST140', 705, 825], ['s2', 'HIST140', 780, 840],
     ['s1', 'CHEM120', 600, 720], ['s1', 'MATH101', 765, 825], ['s2', 'MATH101', 660, 780],
     ['s4', 'MATH101H', 540, 600]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'MATH101', 'PHYS110', 30], ['s2', 'CHEM120', 'MATH101', 30], ['s4', 'MATH101H', 'ECON150', 30]]),
  ('partial repair guard 3',
   [[['s3', 'ECON150', 780, 840], ['s4', 'MATH101H', 600, 720], ['s3', 'HIST140', 600, 720],
     ['s4', 'HIST140', 1050, 1110], ['s4', 'CHEM120', 870, 990], ['s4', 'BIO130', 780, 900],
     ['s2', 'HIST140', 705, 795], ['s2', 'CHEM120', 600, 690]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'city',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s2', 'CHEM120', 'HIST140', 15], ['s4', 'BIO130', 'CHEM120', 30]]),
  ('boundary control 4', [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('boundary control 5',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('normal control 6',
   [[['s4', 'ECON150', 600, 660], ['s2', 'PHYS110', 690, 780], ['s4', 'MATH101H', 675, 765],
     ['s4', 'MATH101', 780, 840], ['s2', 'CHEM120', 540, 660], ['s4', 'BIO130', 840, 960]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s4', 'ECON150', 'MATH101H', 15], ['s4', 'MATH101', 'BIO130', 30]]),
  ('normal control 7',
   [[['s2', 'CHEM120', 1035, 1095], ['s2', 'PHYS110', 600, 720], ['s2', 'ECON150', 945, 1035],
     ['s2', 'HIST140', 810, 930]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 60}],
   []),
  ('normal control 8',
   [[['s3', 'PHYS110', 825, 885], ['s3', 'BIO130', 675, 735], ['s3', 'CHEM120', 540, 660],
     ['s3', 'HIST140', 945, 1035]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'city',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s3', 'CHEM120', 'BIO130', 45]])],
 [('regression: same campus overlap 1',
   [[['s2', 'PHYS110', 751, 841], ['s2', 'BIO130', 841, 901], ['s2', 'CHEM120', 600, 660],
     ['s1', 'PHYS110', 885, 975], ['s1', 'ECON150', 705, 795], ['s2', 'ECON150', 691, 781],
     ['s1', 'BIO130', 540, 660], ['s1', 'HIST140', 945, 1035]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'PHYS110', 'HIST140', 30], ['s2', 'ECON150', 'PHYS110', 60]]),
  ('regression variant: same campus overlap 2',
   [[['s3', 'CHEM120', 915, 1035], ['s4', 'MATH101H', 690, 780], ['s2', 'HIST140', 690, 750],
     ['s3', 'ECON150', 600, 720], ['s4', 'BIO130', 540, 600], ['s2', 'MATH101', 540, 660],
     ['s2', 'BIO130', 839, 959], ['s3', 'MATH101', 840, 900], ['s4', 'MATH101', 570, 630],
     ['s3', 'BIO130', 720, 810], ['s2', 'CHEM120', 779, 869]],
    {'MATH101': 'city',
     'MATH101H': 'north',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'MATH101', 'HIST140', 30], ['s2', 'HIST140', 'CHEM120', 16], ['s2', 'CHEM120', 'BIO130', 30],
    ['s4', 'BIO130', 'MATH101', 30]]),
  ('partial repair guard 3',
   [[['s2', 'CHEM120', 720, 810], ['s3', 'PHYS110', 735, 855], ['s1', 'MATH101', 1036, 1126],
     ['s1', 'CHEM120', 885, 1005], ['s1', 'MATH101H', 765, 885], ['s1', 'BIO130', 600, 720],
     ['s3', 'BIO130', 600, 690], ['s2', 'PHYS110', 825, 915], ['s3', 'CHEM120', 885, 975],
     ['s2', 'MATH101H', 540, 630]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 30, 'city|north': 60}],
   [['s2', 'CHEM120', 'PHYS110', 45], ['s3', 'PHYS110', 'CHEM120', 30]]),
  ('boundary control 4',
   [[['s1', 'A', 540, 600], ['s1', 'B', 629, 700]], {'A': 'south', 'B': 'north'}, {'north|south': 30}],
   [['s1', 'A', 'B', 1]]),
  ('boundary control 5', [[['s1', 'A', 540, 600], ['s1', 'B', 590, 700]], {'A': 'north', 'B': 'north'}, {}],
   [['s1', 'A', 'B', 10]]),
  ('normal control 6',
   [[['s2', 'PHYS110', 600, 690], ['s3', 'MATH101H', 600, 660], ['s3', 'PHYS110', 691, 781],
     ['s3', 'BIO130', 1021, 1111], ['s3', 'MATH101', 841, 931], ['s2', 'ECON150', 660, 720]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'PHYS110', 'ECON150', 75]]),
  ('normal control 7',
   [[['s3', 'PHYS110', 750, 870], ['s2', 'MATH101H', 930, 1050], ['s2', 'CHEM120', 675, 735],
     ['s3', 'ECON150', 600, 720], ['s3', 'CHEM120', 900, 1020], ['s2', 'HIST140', 750, 840],
     ['s2', 'BIO130', 540, 630]],
    {'MATH101': 'city',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s3', 'ECON150', 'PHYS110', 30]]),
  ('normal control 8',
   [[['s2', 'ECON150', 600, 660], ['s2', 'PHYS110', 630, 690]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   [['s2', 'ECON150', 'PHYS110', 30]])],
 [('regression: same campus overlap 1',
   [[['s3', 'PHYS110', 600, 690], ['s4', 'PHYS110', 660, 720], ['s4', 'BIO130', 900, 990],
     ['s3', 'HIST140', 750, 870], ['s3', 'CHEM120', 690, 780], ['s4', 'MATH101H', 780, 840],
     ['s3', 'MATH101', 660, 720], ['s4', 'CHEM120', 600, 660]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'north',
     'HIST140': 'city',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 60}],
   [['s3', 'PHYS110', 'MATH101', 30], ['s3', 'MATH101', 'CHEM120', 90], ['s3', 'CHEM120', 'HIST140', 30],
    ['s4', 'CHEM120', 'PHYS110', 60]]),
  ('regression variant: same campus overlap 2',
   [[['s5', 'HIST140', 780, 900], ['s4', 'BIO130', 690, 780], ['s5', 'MATH101H', 540, 600],
     ['s3', 'CHEM120', 645, 705], ['s5', 'PHYS110', 900, 1020], ['s3', 'HIST140', 540, 600],
     ['s4', 'ECON150', 600, 720], ['s5', 'CHEM120', 690, 810]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s4', 'ECON150', 'BIO130', 30], ['s5', 'CHEM120', 'HIST140', 30], ['s5', 'HIST140', 'PHYS110', 45]]),
  ('partial repair guard 3',
   [[['s3', 'HIST140', 540, 660], ['s5', 'PHYS110', 750, 870], ['s5', 'BIO130', 1019, 1079],
     ['s3', 'MATH101H', 900, 1020], ['s5', 'ECON150', 600, 690], ['s5', 'CHEM120', 930, 990],
     ['s3', 'CHEM120', 720, 840]],
    {'MATH101': 'south',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 60}],
   [['s5', 'CHEM120', 'BIO130', 1]]),
  ('boundary control 4',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 629, 700]], {'A': 'south', 'B': 'north'}, {'north|south': 30}],
   [['s1', 'A', 'B', 1]]),
  ('normal control 6',
   [[['s5', 'BIO130', 540, 630], ['s2', 'MATH101H', 720, 810], ['s2', 'MATH101', 600, 660],
     ['s5', 'ECON150', 600, 690]],
    {'MATH101': 'city',
     'MATH101H': 'south',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'city',
     'ECON150': 'south'},
    {'north|south': 45, 'city|north': 30}],
   [['s5', 'BIO130', 'ECON150', 30]]),
  ('normal control 7',
   [[['s4', 'ECON150', 990, 1080], ['s5', 'CHEM120', 540, 600], ['s5', 'ECON150', 690, 810],
     ['s5', 'MATH101H', 1080, 1140], ['s5', 'PHYS110', 870, 990], ['s4', 'MATH101H', 1050, 1110],
     ['s4', 'BIO130', 810, 930], ['s4', 'MATH101', 600, 720]],
    {'MATH101': 'north',
     'MATH101H': 'north',
     'PHYS110': 'south',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 30, 'city|north': 30}],
   [['s4', 'ECON150', 'MATH101H', 60]]),
  ('normal control 8',
   [[['s2', 'MATH101H', 600, 720], ['s4', 'PHYS110', 675, 795], ['s4', 'MATH101H', 825, 915],
     ['s1', 'BIO130', 540, 630], ['s4', 'MATH101', 885, 1005], ['s2', 'PHYS110', 780, 840],
     ['s1', 'PHYS110', 659, 719], ['s4', 'ECON150', 540, 630]],
    {'MATH101': 'south',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'city',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 30, 'city|north': 30}],
   [['s1', 'BIO130', 'PHYS110', 1], ['s4', 'MATH101H', 'MATH101', 30]])],
 [('regression: same campus overlap 1',
   [[['s1', 'MATH101H', 751, 811], ['s2', 'MATH101', 540, 630], ['s1', 'MATH101', 826, 946],
     ['s2', 'HIST140', 749, 869], ['s2', 'PHYS110', 659, 779], ['s1', 'BIO130', 600, 720],
     ['s1', 'CHEM120', 961, 1021]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'north',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 30}],
   [['s1', 'MATH101', 'CHEM120', 15], ['s2', 'MATH101', 'PHYS110', 1], ['s2', 'PHYS110', 'HIST140', 30]]),
  ('regression variant: same campus overlap 2',
   [[['s1', 'PHYS110', 690, 750], ['s1', 'ECON150', 600, 690], ['s1', 'MATH101H', 660, 720]],
    {'MATH101': 'south',
     'MATH101H': 'north',
     'PHYS110': 'north',
     'CHEM120': 'north',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'south'},
    {'north|south': 30, 'city|north': 60}],
   [['s1', 'ECON150', 'MATH101H', 60], ['s1', 'MATH101H', 'PHYS110', 30]]),
  ('partial repair guard 3',
   [[['s3', 'MATH101', 705, 825], ['s4', 'PHYS110', 660, 780], ['s4', 'MATH101', 989, 1049],
     ['s4', 'CHEM120', 600, 660], ['s3', 'PHYS110', 840, 960], ['s4', 'HIST140', 809, 929],
     ['s3', 'BIO130', 540, 660]],
    {'MATH101': 'city',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 30}],
   []),
  ('boundary control 4',
   [[['s1', 'B', 700, 760], ['s1', 'A', 540, 600]], {'A': 'north', 'B': 'city'}, {'city|north': 60}], []),
  ('boundary control 5',
   [[['s1', 'A', 540, 600], ['s1', 'B', 630, 700]], {'A': 'north', 'B': 'south'}, {'north|south': 30}], []),
  ('normal control 6',
   [[['s1', 'HIST140', 705, 765], ['s1', 'ECON150', 825, 915], ['s1', 'PHYS110', 915, 975],
     ['s1', 'BIO130', 540, 660]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'city',
     'CHEM120': 'north',
     'BIO130': 'north',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 60}],
   []),
  ('normal control 7',
   [[['s2', 'HIST140', 720, 840], ['s5', 'PHYS110', 750, 840], ['s1', 'PHYS110', 600, 660],
     ['s5', 'BIO130', 600, 720], ['s1', 'MATH101', 675, 765], ['s2', 'PHYS110', 540, 630],
     ['s1', 'BIO130', 796, 856]],
    {'MATH101': 'north',
     'MATH101H': 'city',
     'PHYS110': 'north',
     'CHEM120': 'south',
     'BIO130': 'city',
     'HIST140': 'south',
     'ECON150': 'city'},
    {'north|south': 45, 'city|north': 30}],
   []),
  ('normal control 8',
   [[['s4', 'PHYS110', 720, 780], ['s4', 'MATH101', 1020, 1110], ['s5', 'ECON150', 931, 1051],
     ['s4', 'MATH101H', 600, 720], ['s5', 'HIST140', 600, 720], ['s1', 'PHYS110', 720, 810],
     ['s5', 'MATH101H', 780, 900], ['s4', 'CHEM120', 840, 960], ['s1', 'BIO130', 600, 720]],
    {'MATH101': 'north',
     'MATH101H': 'south',
     'PHYS110': 'south',
     'CHEM120': 'south',
     'BIO130': 'south',
     'HIST140': 'north',
     'ECON150': 'north'},
    {'north|south': 45, 'city|north': 60}],
   [['s5', 'MATH101H', 'ECON150', 14]])]]
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: same campus overlap 1	`[['s1', 'A', 'B', 10]]`	`[['s1', 'A', 'B', 10]]`	Passed
regression variant: same campus overlap 2	`[['s2', 'BIO130', 'ECON150', 45], ['s4', 'MATH101', 'CHEM120', 30], ['s4', 'CHEM120', 'PHYS110', 60], ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]`	`[['s2', 'BIO130', 'ECON150', 45], ['s4', 'MATH101', 'CHEM120', 30], ['s4', 'CHEM120', 'PHYS110', 60], ['s5', 'MATH101H', 'BIO130', 15], ['s5', 'BIO130', 'CHEM120', 45]]`	Passed
partial repair guard 3	`[['s1', 'MATH101', 'ECON150', 90], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]`	`[['s1', 'MATH101', 'ECON150', 90], ['s4', 'BIO130', 'CHEM120', 16], ['s4', 'CHEM120', 'MATH101H', 45]]`	Passed
boundary control 4	`[]`	`[]`	Passed
boundary control 5	`[]`	`[]`	Passed
normal control 6	`[]`	`[]`	Passed
normal control 7	`[['s5', 'CHEM120', 'ECON150', 30]]`	`[['s5', 'CHEM120', 'ECON150', 30]]`	Passed
normal control 8	`[['s5', 'MATH101H', 'HIST140', 60]]`	`[['s5', 'MATH101H', 'HIST140', 60]]`	Passed

SHA-256 / 177c0d4bb8cbba1211c7ae2ad1745e1e06ab98c3bfd4c38849454547bf129d7d

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 2026-09-29T14:52:05.990391+00:00.

Case digest / 9293921757eb4138b16ab3dc4bc769537ae2259f4531a787f8d72a6761145f73