FA-68781 / Toll and parking fee computation / Open access

Airport parking weekly cap: a partial day is counted as a full day before the weekly split · case 01

Airport parking weekly cap returns a wrong result when a partial day is counted as a full day before the weekly split.

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

ROOT CAUSE

The partial day is billed both as a full day and as its hourly remainder.

VERIFIED REPAIR

Restore the week and day split rule so that the step reads `weeks, days = divmod(full, 7)`.

Unsuccessful approach: A half-day rule rounds long remainders into a full day that is billed twice.

Case contract

Input {minutes, daily, weekly, hourly}. Full 1440-minute days and a remainder; the remainder costs started hours * hourly capped at daily. Each full 7-day week costs weekly; the leftover full days plus the remainder cost days*daily + remainder charge, capped at weekly.

Why this case matters

Fee engines bill customers in integer cents; a wrong boundary, rounding stage or cap scope silently over- or under-charges.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(x):
    m = x['minutes']
    full, r = divmod(m, 1440)
    part = min(x['daily'], -(-r // 60) * x['hourly'])
    weeks, days = divmod(-(-m // 1440), 7)
    return weeks * x['weekly'] + min(x['weekly'], days * x['daily'] + part)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 5760, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 8800), ({'minutes': 2651, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 4400), ({'minutes': 2156, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 5600), ({'minutes': 28800, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 27000), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 2719, 'daily': 1800, 'weekly': 11000, 'hourly': 500}, 3600), ({'minutes': 7200, 'daily': 2200, 'weekly': 9000, 'hourly': 600}, 9000)], [({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 1757, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 5600), ({'minutes': 20792, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 20800), ({'minutes': 1215, 'daily': 2800, 'weekly': 13000, 'hourly': 500}, 2800), ({'minutes': 780, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 2200), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 28800, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 27000), ({'minutes': 18051, 'daily': 2800, 'weekly': 13000, 'hourly': 600}, 26000)], [({'minutes': 15840, 'daily': 1800, 'weekly': 9000, 'hourly': 400}, 16200), ({'minutes': 25920, 'daily': 1800, 'weekly': 13000, 'hourly': 500}, 33200), ({'minutes': 2339, 'daily': 1800, 'weekly': 11000, 'hourly': 400}, 3600), ({'minutes': 860, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 1800), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 418, 'daily': 2800, 'weekly': 9000, 'hourly': 600}, 2800), ({'minutes': 553, 'daily': 1800, 'weekly': 13000, 'hourly': 600}, 1800), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000)], [({'minutes': 740, 'daily': 2800, 'weekly': 11000, 'hourly': 600}, 2800), ({'minutes': 24656, 'daily': 2200, 'weekly': 13000, 'hourly': 500}, 34100), ({'minutes': 28970, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 27000), ({'minutes': 17056, 'daily': 1800, 'weekly': 9000, 'hourly': 400}, 18000), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 20909, 'daily': 2800, 'weekly': 9000, 'hourly': 400}, 20800), ({'minutes': 14400, 'daily': 2200, 'weekly': 9000, 'hourly': 500}, 15600), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000)], [({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 11520, 'daily': 2800, 'weekly': 13000, 'hourly': 400}, 15800), ({'minutes': 2346, 'daily': 2800, 'weekly': 11000, 'hourly': 600}, 5600), ({'minutes': 15840, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 19800), ({'minutes': 1090, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 1800), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 25920, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 29200), ({'minutes': 8762, 'daily': 1800, 'weekly': 9000, 'hourly': 600}, 9000)]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('fee oracle' + ' %d' % i, 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
fee oracle 0	`11000`	`11000`	Passed
fee oracle 1	`8800`	`8800`	Passed
fee oracle 2	`6600`	`4400`	Failed
fee oracle 3	`8400`	`5600`	Failed
fee oracle 4	`27000`	`27000`	Passed
fee oracle 5	`14200`	`12000`	Failed
fee oracle 6	`5400`	`3600`	Failed
fee oracle 7	`9000`	`9000`	Passed

SHA-256 / b2fe9218a781921bd4103e1ecddd16cfe450340b447d4694071c0577eb155a01

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(x):
    m = x['minutes']
    full, r = divmod(m, 1440)
    part = min(x['daily'], -(-r // 60) * x['hourly'])
    weeks, days = full // 7, full % 7 + (1 if r >= 720 else 0)
    return weeks * x['weekly'] + min(x['weekly'], days * x['daily'] + part)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 5760, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 8800), ({'minutes': 2651, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 4400), ({'minutes': 2156, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 5600), ({'minutes': 28800, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 27000), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 2719, 'daily': 1800, 'weekly': 11000, 'hourly': 500}, 3600), ({'minutes': 7200, 'daily': 2200, 'weekly': 9000, 'hourly': 600}, 9000)], [({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 1757, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 5600), ({'minutes': 20792, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 20800), ({'minutes': 1215, 'daily': 2800, 'weekly': 13000, 'hourly': 500}, 2800), ({'minutes': 780, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 2200), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 28800, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 27000), ({'minutes': 18051, 'daily': 2800, 'weekly': 13000, 'hourly': 600}, 26000)], [({'minutes': 15840, 'daily': 1800, 'weekly': 9000, 'hourly': 400}, 16200), ({'minutes': 25920, 'daily': 1800, 'weekly': 13000, 'hourly': 500}, 33200), ({'minutes': 2339, 'daily': 1800, 'weekly': 11000, 'hourly': 400}, 3600), ({'minutes': 860, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 1800), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 418, 'daily': 2800, 'weekly': 9000, 'hourly': 600}, 2800), ({'minutes': 553, 'daily': 1800, 'weekly': 13000, 'hourly': 600}, 1800), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000)], [({'minutes': 740, 'daily': 2800, 'weekly': 11000, 'hourly': 600}, 2800), ({'minutes': 24656, 'daily': 2200, 'weekly': 13000, 'hourly': 500}, 34100), ({'minutes': 28970, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 27000), ({'minutes': 17056, 'daily': 1800, 'weekly': 9000, 'hourly': 400}, 18000), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 20909, 'daily': 2800, 'weekly': 9000, 'hourly': 400}, 20800), ({'minutes': 14400, 'daily': 2200, 'weekly': 9000, 'hourly': 500}, 15600), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000)], [({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 11520, 'daily': 2800, 'weekly': 13000, 'hourly': 400}, 15800), ({'minutes': 2346, 'daily': 2800, 'weekly': 11000, 'hourly': 600}, 5600), ({'minutes': 15840, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 19800), ({'minutes': 1090, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 1800), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 25920, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 29200), ({'minutes': 8762, 'daily': 1800, 'weekly': 9000, 'hourly': 600}, 9000)]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('fee oracle' + ' %d' % i, 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
fee oracle 0	`11000`	`11000`	Passed
fee oracle 1	`8800`	`8800`	Passed
fee oracle 2	`6600`	`4400`	Failed
fee oracle 3	`5600`	`5600`	Passed
fee oracle 4	`27000`	`27000`	Passed
fee oracle 5	`12000`	`12000`	Passed
fee oracle 6	`5400`	`3600`	Failed
fee oracle 7	`9000`	`9000`	Passed

SHA-256 / eee7b599d0a8dceac68f1895eef20f450c91024562fbd51ea2532ac1929e4c84

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(x):
    m = x['minutes']
    full, r = divmod(m, 1440)
    part = min(x['daily'], -(-r // 60) * x['hourly'])
    weeks, days = divmod(full, 7)
    return weeks * x['weekly'] + min(x['weekly'], days * x['daily'] + part)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 5760, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 8800), ({'minutes': 2651, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 4400), ({'minutes': 2156, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 5600), ({'minutes': 28800, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 27000), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 2719, 'daily': 1800, 'weekly': 11000, 'hourly': 500}, 3600), ({'minutes': 7200, 'daily': 2200, 'weekly': 9000, 'hourly': 600}, 9000)], [({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 1757, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 5600), ({'minutes': 20792, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 20800), ({'minutes': 1215, 'daily': 2800, 'weekly': 13000, 'hourly': 500}, 2800), ({'minutes': 780, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 2200), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 28800, 'daily': 2800, 'weekly': 9000, 'hourly': 500}, 27000), ({'minutes': 18051, 'daily': 2800, 'weekly': 13000, 'hourly': 600}, 26000)], [({'minutes': 15840, 'daily': 1800, 'weekly': 9000, 'hourly': 400}, 16200), ({'minutes': 25920, 'daily': 1800, 'weekly': 13000, 'hourly': 500}, 33200), ({'minutes': 2339, 'daily': 1800, 'weekly': 11000, 'hourly': 400}, 3600), ({'minutes': 860, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 1800), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 418, 'daily': 2800, 'weekly': 9000, 'hourly': 600}, 2800), ({'minutes': 553, 'daily': 1800, 'weekly': 13000, 'hourly': 600}, 1800), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000)], [({'minutes': 740, 'daily': 2800, 'weekly': 11000, 'hourly': 600}, 2800), ({'minutes': 24656, 'daily': 2200, 'weekly': 13000, 'hourly': 500}, 34100), ({'minutes': 28970, 'daily': 2200, 'weekly': 9000, 'hourly': 400}, 27000), ({'minutes': 17056, 'daily': 1800, 'weekly': 9000, 'hourly': 400}, 18000), ({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 20909, 'daily': 2800, 'weekly': 9000, 'hourly': 400}, 20800), ({'minutes': 14400, 'daily': 2200, 'weekly': 9000, 'hourly': 500}, 15600), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000)], [({'minutes': 10180, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 12000), ({'minutes': 11520, 'daily': 2800, 'weekly': 13000, 'hourly': 400}, 15800), ({'minutes': 2346, 'daily': 2800, 'weekly': 11000, 'hourly': 600}, 5600), ({'minutes': 15840, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 19800), ({'minutes': 1090, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 1800), ({'minutes': 8000, 'daily': 2200, 'weekly': 11000, 'hourly': 500}, 11000), ({'minutes': 25920, 'daily': 1800, 'weekly': 11000, 'hourly': 600}, 29200), ({'minutes': 8762, 'daily': 1800, 'weekly': 9000, 'hourly': 600}, 9000)]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('fee oracle' + ' %d' % i, 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
fee oracle 0	`11000`	`11000`	Passed
fee oracle 1	`8800`	`8800`	Passed
fee oracle 2	`4400`	`4400`	Passed
fee oracle 3	`5600`	`5600`	Passed
fee oracle 4	`27000`	`27000`	Passed
fee oracle 5	`12000`	`12000`	Passed
fee oracle 6	`3600`	`3600`	Passed
fee oracle 7	`9000`	`9000`	Passed

SHA-256 / 6c31fead9445c33ef480929e14a245833dc4a5d9f140888679afad94de37659d

Verification & scope

A deterministic, bounded toy model with a stipulated contract; it makes no claim of conformance to any agency manual or standard. 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 2026-09-29T14:48:05.459828+00:00.

Case digest / 43293d8d7652c8aa47c020f10f8a9568de454472aa846e67cdf534d2c5c54cb0