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FA-85606 / Ride-hailing fare and surge pricing / Open access

Fare exactly at the promo minimum rejected · case 01

A 10.00 ride fails a 10.00 minimum-spend promo.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The minimum-fare check uses <=.

VERIFIED REPAIR

Reject only fares strictly below the minimum.

Unsuccessful approach: Comparing whole dollars accepts fares a few cents below a minimum that is not a whole-dollar amount.

Case contract

Validate a promo in order: expired if now_day is after expires_day (the expiry day itself is valid), exhausted if no uses remain, not_first if first-ride-only and the rider has prior rides, min_fare if the fare (cents) is below min_fare. A valid pct promo takes value% of the fare (floored), capped at cap cents when cap is not None (a cap of 0 means a zero discount); a flat promo takes value but never more than the fare. Ride credits then cover up to the remaining fare. Return discount, credit used, amount due and reason.

Why this case matters

Ride-hailing prices are computed per trip at scale; ordering, unit and boundary slips become systematic over- or under-charging.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(promo, ride, now_day):
    reason = None
    if now_day > promo['expires_day']:
        reason = 'expired'
    elif promo['uses_left'] <= 0:
        reason = 'exhausted'
    elif promo['first_ride_only'] and ride['rider_rides'] > 0:
        reason = 'not_first'
    elif ride['fare'] <= promo['min_fare']:
        reason = 'min_fare'
    disc = 0
    if reason is None:
        if promo['kind'] == 'pct':
            disc = ride['fare'] * promo['value'] // 100
            if promo['cap'] is not None:
                disc = min(disc, promo['cap'])
        else:
            disc = min(promo['value'], ride['fare'])
    credit = min(ride['credits'], ride['fare'] - disc)
    return {'discount': disc, 'credit_used': credit, 'due': ride['fare'] - disc - credit, 'reason': reason}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: minimum fare comparison',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 500},
    {'credits': 5000, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 550, 'discount': 500, 'due': 0, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 500},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 1000},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 1,
     'value': 50},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 1}, 101],
   {'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 0,
     'value': 500},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}),
  ('normal control 3',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 500},
    {'credits': 0, 'fare': 700, 'rider_rides': 1}, 99],
   {'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}),
  ('normal control 4',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 1000},
    {'credits': 5000, 'fare': 700, 'rider_rides': 5}, 99],
   {'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'})],
 [('regression: minimum fare comparison',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 250, 'fare': 1050, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 262, 'due': 538, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 10},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 1000},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 1000, 'due': 0, 'reason': None}),
  ('normal control 2',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 25},
    {'credits': 5000, 'fare': 2167, 'rider_rides': 0}, 101],
   {'credit_used': 2167, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 250, 'fare': 2346, 'rider_rides': 5}, 99],
   {'credit_used': 250, 'discount': 0, 'due': 2096, 'reason': 'not_first'}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 3,
     'value': 50},
    {'credits': 0, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 549, 'due': 550, 'reason': None})],
 [('regression: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 250, 'discount': 100, 'due': 650, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 500},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 250, 'discount': 105, 'due': 695, 'reason': None}),
  ('normal control 1',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 500},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 500, 'due': 349, 'reason': None}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 0,
     'value': 50},
    {'credits': 0, 'fare': 1050, 'rider_rides': 0}, 101],
   {'credit_used': 0, 'discount': 0, 'due': 1050, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 2400, 'rider_rides': 5}, 100],
   {'credit_used': 250, 'discount': 240, 'due': 1910, 'reason': None}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 50},
    {'credits': 5000, 'fare': 1050, 'rider_rides': 0}, 100],
   {'credit_used': 1050, 'discount': 0, 'due': 0, 'reason': 'exhausted'})],
 [('regression: minimum fare comparison',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 500, 'discount': 500, 'due': 0, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 250, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 250, 'discount': 0, 'due': 750, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 10},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 0,
     'value': 10},
    {'credits': 5000, 'fare': 1933, 'rider_rides': 0}, 101],
   {'credit_used': 1933, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 500},
    {'credits': 0, 'fare': 1099, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1099, 'reason': 'exhausted'}),
  ('normal control 3',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 1000},
    {'credits': 0, 'fare': 2400, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 1000, 'due': 1400, 'reason': None}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 50},
    {'credits': 0, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1050, 'reason': 'exhausted'})],
 [('regression: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 500, 'due': 500, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 3,
     'value': 10},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 1}, 99],
   {'credit_used': 900, 'discount': 100, 'due': 0, 'reason': None}),
  ('normal control 1',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 10},
    {'credits': 0, 'fare': 700, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 700, 'reason': 'exhausted'}),
  ('normal control 2',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 10},
    {'credits': 0, 'fare': 1099, 'rider_rides': 0}, 101],
   {'credit_used': 0, 'discount': 0, 'due': 1099, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 0,
     'value': 25},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 2500},
    {'credits': 250, 'fare': 700, 'rider_rides': 0}, 101],
   {'credit_used': 250, 'discount': 0, 'due': 450, 'reason': 'expired'})]]
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 fixtureActualExpectedOutcome
regression: minimum fare comparison{'credit_used': 1050, 'discount': 0, 'due': 0, 'reason': 'min_fare'}{'credit_used': 550, 'discount': 500, 'due': 0, 'reason': None}Failed
partial repair probe: minimum fare comparison{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}Passed
second regression{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}Passed
normal control 1{'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}{'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}Passed
normal control 2{'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}{'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}Passed
normal control 3{'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}{'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}Passed
normal control 4{'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'}{'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'}Passed

SHA-256 / 7031d9a6f03beb55e356e47cdd2aec6f97b49abcd9d5827c3b51ca69b91dde9f

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(promo, ride, now_day):
    reason = None
    if now_day > promo['expires_day']:
        reason = 'expired'
    elif promo['uses_left'] <= 0:
        reason = 'exhausted'
    elif promo['first_ride_only'] and ride['rider_rides'] > 0:
        reason = 'not_first'
    elif ride['fare'] // 100 < promo['min_fare'] // 100:
        reason = 'min_fare'
    disc = 0
    if reason is None:
        if promo['kind'] == 'pct':
            disc = ride['fare'] * promo['value'] // 100
            if promo['cap'] is not None:
                disc = min(disc, promo['cap'])
        else:
            disc = min(promo['value'], ride['fare'])
    credit = min(ride['credits'], ride['fare'] - disc)
    return {'discount': disc, 'credit_used': credit, 'due': ride['fare'] - disc - credit, 'reason': reason}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: minimum fare comparison',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 500},
    {'credits': 5000, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 550, 'discount': 500, 'due': 0, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 500},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 1000},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 1,
     'value': 50},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 1}, 101],
   {'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 0,
     'value': 500},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}),
  ('normal control 3',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 500},
    {'credits': 0, 'fare': 700, 'rider_rides': 1}, 99],
   {'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}),
  ('normal control 4',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 1000},
    {'credits': 5000, 'fare': 700, 'rider_rides': 5}, 99],
   {'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'})],
 [('regression: minimum fare comparison',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 250, 'fare': 1050, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 262, 'due': 538, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 10},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 1000},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 1000, 'due': 0, 'reason': None}),
  ('normal control 2',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 25},
    {'credits': 5000, 'fare': 2167, 'rider_rides': 0}, 101],
   {'credit_used': 2167, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 250, 'fare': 2346, 'rider_rides': 5}, 99],
   {'credit_used': 250, 'discount': 0, 'due': 2096, 'reason': 'not_first'}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 3,
     'value': 50},
    {'credits': 0, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 549, 'due': 550, 'reason': None})],
 [('regression: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 250, 'discount': 100, 'due': 650, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 500},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 250, 'discount': 105, 'due': 695, 'reason': None}),
  ('normal control 1',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 500},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 500, 'due': 349, 'reason': None}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 0,
     'value': 50},
    {'credits': 0, 'fare': 1050, 'rider_rides': 0}, 101],
   {'credit_used': 0, 'discount': 0, 'due': 1050, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 2400, 'rider_rides': 5}, 100],
   {'credit_used': 250, 'discount': 240, 'due': 1910, 'reason': None}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 50},
    {'credits': 5000, 'fare': 1050, 'rider_rides': 0}, 100],
   {'credit_used': 1050, 'discount': 0, 'due': 0, 'reason': 'exhausted'})],
 [('regression: minimum fare comparison',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 500, 'discount': 500, 'due': 0, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 250, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 250, 'discount': 0, 'due': 750, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 10},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 0,
     'value': 10},
    {'credits': 5000, 'fare': 1933, 'rider_rides': 0}, 101],
   {'credit_used': 1933, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 500},
    {'credits': 0, 'fare': 1099, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1099, 'reason': 'exhausted'}),
  ('normal control 3',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 1000},
    {'credits': 0, 'fare': 2400, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 1000, 'due': 1400, 'reason': None}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 50},
    {'credits': 0, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1050, 'reason': 'exhausted'})],
 [('regression: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 500, 'due': 500, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 3,
     'value': 10},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 1}, 99],
   {'credit_used': 900, 'discount': 100, 'due': 0, 'reason': None}),
  ('normal control 1',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 10},
    {'credits': 0, 'fare': 700, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 700, 'reason': 'exhausted'}),
  ('normal control 2',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 10},
    {'credits': 0, 'fare': 1099, 'rider_rides': 0}, 101],
   {'credit_used': 0, 'discount': 0, 'due': 1099, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 0,
     'value': 25},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 2500},
    {'credits': 250, 'fare': 700, 'rider_rides': 0}, 101],
   {'credit_used': 250, 'discount': 0, 'due': 450, 'reason': 'expired'})]]
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 fixtureActualExpectedOutcome
regression: minimum fare comparison{'credit_used': 550, 'discount': 500, 'due': 0, 'reason': None}{'credit_used': 550, 'discount': 500, 'due': 0, 'reason': None}Passed
partial repair probe: minimum fare comparison{'credit_used': 0, 'discount': 500, 'due': 500, 'reason': None}{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}Failed
second regression{'credit_used': 0, 'discount': 1000, 'due': 0, 'reason': None}{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}Failed
normal control 1{'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}{'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}Passed
normal control 2{'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}{'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}Passed
normal control 3{'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}{'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}Passed
normal control 4{'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'}{'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'}Passed

SHA-256 / 9aa7ddd6a97c9154e4916f7d22bae76b2cd7caa4178faa90d31f313958b3ab64

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(promo, ride, now_day):
    reason = None
    if now_day > promo['expires_day']:
        reason = 'expired'
    elif promo['uses_left'] <= 0:
        reason = 'exhausted'
    elif promo['first_ride_only'] and ride['rider_rides'] > 0:
        reason = 'not_first'
    elif ride['fare'] < promo['min_fare']:
        reason = 'min_fare'
    disc = 0
    if reason is None:
        if promo['kind'] == 'pct':
            disc = ride['fare'] * promo['value'] // 100
            if promo['cap'] is not None:
                disc = min(disc, promo['cap'])
        else:
            disc = min(promo['value'], ride['fare'])
    credit = min(ride['credits'], ride['fare'] - disc)
    return {'discount': disc, 'credit_used': credit, 'due': ride['fare'] - disc - credit, 'reason': reason}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: minimum fare comparison',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 500},
    {'credits': 5000, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 550, 'discount': 500, 'due': 0, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 500},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 1000},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 1,
     'value': 50},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 1}, 101],
   {'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 0,
     'value': 500},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}),
  ('normal control 3',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 500},
    {'credits': 0, 'fare': 700, 'rider_rides': 1}, 99],
   {'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}),
  ('normal control 4',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 1000},
    {'credits': 5000, 'fare': 700, 'rider_rides': 5}, 99],
   {'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'})],
 [('regression: minimum fare comparison',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 250, 'fare': 1050, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 262, 'due': 538, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 10},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 1000},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 1000, 'due': 0, 'reason': None}),
  ('normal control 2',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 25},
    {'credits': 5000, 'fare': 2167, 'rider_rides': 0}, 101],
   {'credit_used': 2167, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 250, 'fare': 2346, 'rider_rides': 5}, 99],
   {'credit_used': 250, 'discount': 0, 'due': 2096, 'reason': 'not_first'}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 3,
     'value': 50},
    {'credits': 0, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 549, 'due': 550, 'reason': None})],
 [('regression: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 250, 'discount': 100, 'due': 650, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 500},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 250, 'discount': 105, 'due': 695, 'reason': None}),
  ('normal control 1',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 500},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 500, 'due': 349, 'reason': None}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 0,
     'value': 50},
    {'credits': 0, 'fare': 1050, 'rider_rides': 0}, 101],
   {'credit_used': 0, 'discount': 0, 'due': 1050, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 3,
     'value': 10},
    {'credits': 250, 'fare': 2400, 'rider_rides': 5}, 100],
   {'credit_used': 250, 'discount': 240, 'due': 1910, 'reason': None}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 50},
    {'credits': 5000, 'fare': 1050, 'rider_rides': 0}, 100],
   {'credit_used': 1050, 'discount': 0, 'due': 0, 'reason': 'exhausted'})],
 [('regression: minimum fare comparison',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 500, 'discount': 500, 'due': 0, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 250, 'fare': 1000, 'rider_rides': 0}, 99],
   {'credit_used': 250, 'discount': 0, 'due': 750, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 10},
    {'credits': 0, 'fare': 1000, 'rider_rides': 5}, 100],
   {'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}),
  ('normal control 1',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 0,
     'uses_left': 0,
     'value': 10},
    {'credits': 5000, 'fare': 1933, 'rider_rides': 0}, 101],
   {'credit_used': 1933, 'discount': 0, 'due': 0, 'reason': 'expired'}),
  ('normal control 2',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 500},
    {'credits': 0, 'fare': 1099, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1099, 'reason': 'exhausted'}),
  ('normal control 3',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'flat',
     'min_fare': 0,
     'uses_left': 3,
     'value': 1000},
    {'credits': 0, 'fare': 2400, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 1000, 'due': 1400, 'reason': None}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 50},
    {'credits': 0, 'fare': 1050, 'rider_rides': 0}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 1050, 'reason': 'exhausted'})],
 [('regression: minimum fare comparison',
   [{'cap': 800,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 1,
     'value': 50},
    {'credits': 0, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 0, 'discount': 500, 'due': 500, 'reason': None}),
  ('partial repair probe: minimum fare comparison',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': True,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 3,
     'value': 25},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 0}, 100],
   {'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'min_fare'}),
  ('second regression',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 3,
     'value': 10},
    {'credits': 5000, 'fare': 1000, 'rider_rides': 1}, 99],
   {'credit_used': 900, 'discount': 100, 'due': 0, 'reason': None}),
  ('normal control 1',
   [{'cap': 300,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 10},
    {'credits': 0, 'fare': 700, 'rider_rides': 5}, 99],
   {'credit_used': 0, 'discount': 0, 'due': 700, 'reason': 'exhausted'}),
  ('normal control 2',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1050,
     'uses_left': 0,
     'value': 10},
    {'credits': 0, 'fare': 1099, 'rider_rides': 0}, 101],
   {'credit_used': 0, 'discount': 0, 'due': 1099, 'reason': 'expired'}),
  ('normal control 3',
   [{'cap': 0,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'pct',
     'min_fare': 1000,
     'uses_left': 0,
     'value': 25},
    {'credits': 250, 'fare': 1099, 'rider_rides': 0}, 100],
   {'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}),
  ('normal control 4',
   [{'cap': None,
     'expires_day': 100,
     'first_ride_only': False,
     'kind': 'flat',
     'min_fare': 1050,
     'uses_left': 1,
     'value': 2500},
    {'credits': 250, 'fare': 700, 'rider_rides': 0}, 101],
   {'credit_used': 250, 'discount': 0, 'due': 450, 'reason': 'expired'})]]
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 fixtureActualExpectedOutcome
regression: minimum fare comparison{'credit_used': 550, 'discount': 500, 'due': 0, 'reason': None}{'credit_used': 550, 'discount': 500, 'due': 0, 'reason': None}Passed
partial repair probe: minimum fare comparison{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}Passed
second regression{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}{'credit_used': 0, 'discount': 0, 'due': 1000, 'reason': 'min_fare'}Passed
normal control 1{'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}{'credit_used': 1000, 'discount': 0, 'due': 0, 'reason': 'expired'}Passed
normal control 2{'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}{'credit_used': 250, 'discount': 0, 'due': 849, 'reason': 'exhausted'}Passed
normal control 3{'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}{'credit_used': 0, 'discount': 500, 'due': 200, 'reason': None}Passed
normal control 4{'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'}{'credit_used': 700, 'discount': 0, 'due': 0, 'reason': 'min_fare'}Passed

SHA-256 / 3f524b2800da2cc4876259fd981ae84c985e182770437c05cc1f6a83e09aca4a

Verification & scope

A deterministic toy pricing contract stipulated for this example; it does not reproduce the pricing of any real ride-hailing operator or regulator. 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 2026-09-29T14:50:41.882261+00:00.

Case digest / 36be8940ecb5d229f38c951aec862e8ebeaf5a1a371310a66db29a82e5fa6c79