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FA-60541 / Loyalty points ledgers / Open access

Promotion stacking rules: uncapped sentinel · case 01

Promotions with no cap award zero bonus points.

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

ROOT CAUSE

The cap is applied even when it is 0, which means uncapped.

THE FAILURE

The cap is applied even when it is 0, which means uncapped.

Unsuccessful approach: Applying caps only to multiplier promos leaves capped fixed promos uncapped.

Case contract

Input {base, promos:[{id,kind,value,stackable,cap}]}. A multiplier promo (value in percent) gives floor(base*(value-100)/100) extra; a fixed promo gives value. Each extra is capped at cap when cap > 0. All stackable extras apply; of the non-stackable promos only the single best capped extra applies (ties to the lower id), in addition to the stackable ones. Return {bonus, applied ids sorted}.

Why this case matters

Member point balances, statements and the program liability depend on this ledger rule.

1 / The failure

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

N = 1
observations = []
def solve(x):
    st = []
    ns = []
    for p in x['promos']:
        if p['kind'] == 'multiplier':
            e = x['base'] * (p['value'] - 100) // 100
        else:
            e = p['value']
        if True:
            e = min(e, p['cap'])
        (st if p['stackable'] else ns).append([e, p['id']])
    bonus = sum(e for e, _ in st)
    applied = [i for _, i in st]
    if ns:
        best = min(ns, key=lambda r: (-r[0], r[1]))
        bonus += best[0]
        applied.append(best[1])
    return {'bonus': bonus, 'applied': sorted(applied)}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['mixed promos', {'base': 1001, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1501, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2501}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3001, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 101, 'stackable': True, 'cap': 0}]}, {'bonus': 301, 'applied': [3, 9]}], ['no promos', {'base': 10, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 111, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 77, 'applied': [5]}], ['odd base', {'base': 334, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 333, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 501, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 531, 'applied': [1, 2, 3]}]], [['mixed promos', {'base': 1002, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1503, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2502}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3002, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 102, 'stackable': True, 'cap': 0}]}, {'bonus': 302, 'applied': [3, 9]}], ['no promos', {'base': 20, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 112, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 84, 'applied': [5]}], ['odd base', {'base': 335, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 334, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 502, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 532, 'applied': [1, 2, 3]}]], [['mixed promos', {'base': 1003, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1504, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2503}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3003, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 103, 'stackable': True, 'cap': 0}]}, {'bonus': 303, 'applied': [3, 9]}], ['no promos', {'base': 30, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 113, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 91, 'applied': [5]}], ['odd base', {'base': 336, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 336, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 503, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 533, 'applied': [1, 2, 3]}]], [['mixed promos', {'base': 1004, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1506, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2504}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3004, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 104, 'stackable': True, 'cap': 0}]}, {'bonus': 304, 'applied': [3, 9]}], ['no promos', {'base': 40, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 114, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 98, 'applied': [5]}], ['odd base', {'base': 337, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 336, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 504, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 534, 'applied': [1, 2, 3]}]], [['mixed promos', {'base': 1005, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1507, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2505}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3005, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 105, 'stackable': True, 'cap': 0}]}, {'bonus': 305, 'applied': [3, 9]}], ['no promos', {'base': 50, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 115, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 105, 'applied': [5]}], ['odd base', {'base': 338, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 337, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 505, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 535, 'applied': [1, 2, 3]}]]]
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
mixed promos{'applied': [1, 2], 'bonus': 0}{'applied': [1, 3], 'bonus': 1501}Failed
caps{'applied': [1, 2], 'bonus': 3001}{'applied': [1, 2], 'bonus': 3001}Passed
tie on value{'applied': [3, 9], 'bonus': 0}{'applied': [3, 9], 'bonus': 301}Failed
no promos{'applied': [], 'bonus': 0}{'applied': [], 'bonus': 0}Passed
only non stackable{'applied': [6], 'bonus': 40}{'applied': [5], 'bonus': 77}Failed
odd base{'applied': [1, 2], 'bonus': 0}{'applied': [1, 2], 'bonus': 333}Failed
best beats stack{'applied': [1, 2, 3], 'bonus': 0}{'applied': [1, 2, 3], 'bonus': 531}Failed

SHA-256 / b6f4a459f5efda67c8ccf70a85d61e19654cd1d9ccf73a6e71cf67fbc383c417

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(x):
    st = []
    ns = []
    for p in x['promos']:
        if p['kind'] == 'multiplier':
            e = x['base'] * (p['value'] - 100) // 100
        else:
            e = p['value']
        if p['cap'] > 0 and p['kind'] == 'multiplier':
            e = min(e, p['cap'])
        (st if p['stackable'] else ns).append([e, p['id']])
    bonus = sum(e for e, _ in st)
    applied = [i for _, i in st]
    if ns:
        best = min(ns, key=lambda r: (-r[0], r[1]))
        bonus += best[0]
        applied.append(best[1])
    return {'bonus': bonus, 'applied': sorted(applied)}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['mixed promos', {'base': 1001, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1501, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2501}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3001, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 101, 'stackable': True, 'cap': 0}]}, {'bonus': 301, 'applied': [3, 9]}], ['no promos', {'base': 10, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 111, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 77, 'applied': [5]}], ['odd base', {'base': 334, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 333, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 501, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 531, 'applied': [1, 2, 3]}]], [['mixed promos', {'base': 1002, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1503, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2502}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3002, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 102, 'stackable': True, 'cap': 0}]}, {'bonus': 302, 'applied': [3, 9]}], ['no promos', {'base': 20, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 112, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 84, 'applied': [5]}], ['odd base', {'base': 335, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 334, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 502, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 532, 'applied': [1, 2, 3]}]], [['mixed promos', {'base': 1003, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1504, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2503}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3003, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 103, 'stackable': True, 'cap': 0}]}, {'bonus': 303, 'applied': [3, 9]}], ['no promos', {'base': 30, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 113, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 91, 'applied': [5]}], ['odd base', {'base': 336, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 336, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 503, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 533, 'applied': [1, 2, 3]}]], [['mixed promos', {'base': 1004, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1506, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2504}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3004, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 104, 'stackable': True, 'cap': 0}]}, {'bonus': 304, 'applied': [3, 9]}], ['no promos', {'base': 40, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 114, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 98, 'applied': [5]}], ['odd base', {'base': 337, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 336, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 504, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 534, 'applied': [1, 2, 3]}]], [['mixed promos', {'base': 1005, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 200, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 300, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}]}, {'bonus': 1507, 'applied': [1, 3]}], ['caps', {'base': 2000, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 300, 'stackable': True, 'cap': 2505}, {'id': 2, 'kind': 'fixed', 'value': 900, 'stackable': True, 'cap': 500}]}, {'bonus': 3005, 'applied': [1, 2]}], ['tie on value', {'base': 400, 'promos': [{'id': 7, 'kind': 'fixed', 'value': 200, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'multiplier', 'value': 150, 'stackable': False, 'cap': 0}, {'id': 9, 'kind': 'fixed', 'value': 105, 'stackable': True, 'cap': 0}]}, {'bonus': 305, 'applied': [3, 9]}], ['no promos', {'base': 50, 'promos': []}, {'bonus': 0, 'applied': []}], ['only non stackable', {'base': 700, 'promos': [{'id': 4, 'kind': 'fixed', 'value': 50, 'stackable': False, 'cap': 0}, {'id': 5, 'kind': 'multiplier', 'value': 115, 'stackable': False, 'cap': 0}, {'id': 6, 'kind': 'fixed', 'value': 60, 'stackable': False, 'cap': 40}]}, {'bonus': 105, 'applied': [5]}], ['odd base', {'base': 338, 'promos': [{'id': 1, 'kind': 'multiplier', 'value': 125, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'multiplier', 'value': 175, 'stackable': True, 'cap': 0}]}, {'bonus': 337, 'applied': [1, 2]}], ['best beats stack', {'base': 100, 'promos': [{'id': 1, 'kind': 'fixed', 'value': 10, 'stackable': True, 'cap': 0}, {'id': 2, 'kind': 'fixed', 'value': 505, 'stackable': False, 'cap': 0}, {'id': 3, 'kind': 'fixed', 'value': 20, 'stackable': True, 'cap': 0}]}, {'bonus': 535, 'applied': [1, 2, 3]}]]]
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
mixed promos{'applied': [1, 3], 'bonus': 1501}{'applied': [1, 3], 'bonus': 1501}Passed
caps{'applied': [1, 2], 'bonus': 3401}{'applied': [1, 2], 'bonus': 3001}Failed
tie on value{'applied': [3, 9], 'bonus': 301}{'applied': [3, 9], 'bonus': 301}Passed
no promos{'applied': [], 'bonus': 0}{'applied': [], 'bonus': 0}Passed
only non stackable{'applied': [5], 'bonus': 77}{'applied': [5], 'bonus': 77}Passed
odd base{'applied': [1, 2], 'bonus': 333}{'applied': [1, 2], 'bonus': 333}Passed
best beats stack{'applied': [1, 2, 3], 'bonus': 531}{'applied': [1, 2, 3], 'bonus': 531}Passed

SHA-256 / 8a95a7ee20286117bf2c0b38f599e7aa290a2deec51b4096166a6111bdc4cf98

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Verification & scope

Stipulated bounded loyalty-program model with explicit toy rules; not any real program terms. 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 2026-09-29T14:46:46.667377+00:00.

Case digest / 73f8a78f403012c3bd64c90b7006f884392f6c126e95d94cbbb8a7ef9c3d0eba