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

N = 1
observations = []
def solve(x):
    avail = x['payment'] + x['suspense']
    applied = {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}
    if avail <= x['threshold']:
        return {'applied': applied, 'curtailment': 0, 'refund': 0, 'suspense': avail, 'new_balance': x['balance']}
    for k in ('interest', 'principal', 'late_fee', 'fees'):
        take = min(avail, x['due'][k])
        applied[k] = take
        avail -= take
    room = x['balance'] - applied['principal']
    curt = min(avail, room)
    refund = avail - curt
    return {'applied': applied, 'curtailment': curt, 'refund': refund, 'suspense': 0, 'new_balance': x['balance'] - applied['principal'] - curt}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: threshold boundary', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4500}], ['control 1', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 2', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 7200, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 4000, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 0, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 800}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1250, 'suspense': 700, 'threshold': 1250, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 99300}], ['control 5', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1300, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 6', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1285, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}]], [['regression: threshold boundary', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['control 1', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'curtailment': 165, 'refund': 0, 'suspense': 0, 'new_balance': 2835}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 950, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 350, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2201, 'suspense': 200, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 3999}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 649, 'suspense': 0, 'threshold': 650, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 649, 'new_balance': 100000}], ['control 5', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 0, 'refund': 1550, 'suspense': 0, 'new_balance': 0}], ['control 6', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1000, 'suspense': 0, 'threshold': 535, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 465, 'refund': 0, 'suspense': 0, 'new_balance': 1535}]], [['regression: threshold boundary', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4000}], ['regression: threshold boundary, partial-repair probe', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 499, 'suspense': 200, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 1', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': -200, 'refund': 200, 'suspense': 0, 'new_balance': 0}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 0, 'threshold': 800, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 5000, 'refund': 0, 'suspense': 0, 'new_balance': 94200}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 200, 'new_balance': 800}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 4300}], ['control 5', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'payment': 2084, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 34}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1200}]], [['regression: threshold boundary', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['regression: threshold boundary, partial-repair probe', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1249, 'suspense': 700, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 699, 'refund': 0, 'suspense': 0, 'new_balance': 4301}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 36, 'suspense': 700, 'threshold': 35, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 701, 'refund': 0, 'suspense': 0, 'new_balance': 99}], ['control 2', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 3300}], ['control 3', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 200, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 4200, 'refund': 1000, 'suspense': 0, 'new_balance': 0}], ['control 4', {'due': {'interest': 1250, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 8250, 'suspense': 200, 'threshold': 3250, 'balance': 800}, {'applied': {'interest': 1250, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'curtailment': -1200, 'refund': 6400, 'suspense': 0, 'new_balance': 0}], ['control 5', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100}]], [['regression: threshold boundary', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['regression: threshold boundary, partial-repair probe', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': -1, 'suspense': 200, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 1', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 1300, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}], ['control 2', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 800, 'refund': 165, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 300, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100000}], ['control 4', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 2051, 'suspense': 200, 'threshold': 2050, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 98999}], ['control 5', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'curtailment': 1850, 'refund': 0, 'suspense': 0, 'new_balance': 150}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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)

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

N = 1
observations = []
def solve(x):
    avail = x['payment'] + x['suspense']
    applied = {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}
    if x['payment'] < x['threshold']:
        return {'applied': applied, 'curtailment': 0, 'refund': 0, 'suspense': avail, 'new_balance': x['balance']}
    for k in ('interest', 'principal', 'late_fee', 'fees'):
        take = min(avail, x['due'][k])
        applied[k] = take
        avail -= take
    room = x['balance'] - applied['principal']
    curt = min(avail, room)
    refund = avail - curt
    return {'applied': applied, 'curtailment': curt, 'refund': refund, 'suspense': 0, 'new_balance': x['balance'] - applied['principal'] - curt}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: threshold boundary', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4500}], ['control 1', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 2', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 7200, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 4000, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 0, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 800}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1250, 'suspense': 700, 'threshold': 1250, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 99300}], ['control 5', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1300, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 6', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1285, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}]], [['regression: threshold boundary', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['control 1', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'curtailment': 165, 'refund': 0, 'suspense': 0, 'new_balance': 2835}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 950, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 350, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2201, 'suspense': 200, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 3999}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 649, 'suspense': 0, 'threshold': 650, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 649, 'new_balance': 100000}], ['control 5', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 0, 'refund': 1550, 'suspense': 0, 'new_balance': 0}], ['control 6', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1000, 'suspense': 0, 'threshold': 535, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 465, 'refund': 0, 'suspense': 0, 'new_balance': 1535}]], [['regression: threshold boundary', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4000}], ['regression: threshold boundary, partial-repair probe', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 499, 'suspense': 200, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 1', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': -200, 'refund': 200, 'suspense': 0, 'new_balance': 0}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 0, 'threshold': 800, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 5000, 'refund': 0, 'suspense': 0, 'new_balance': 94200}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 200, 'new_balance': 800}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 4300}], ['control 5', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'payment': 2084, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 34}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1200}]], [['regression: threshold boundary', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['regression: threshold boundary, partial-repair probe', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1249, 'suspense': 700, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 699, 'refund': 0, 'suspense': 0, 'new_balance': 4301}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 36, 'suspense': 700, 'threshold': 35, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 701, 'refund': 0, 'suspense': 0, 'new_balance': 99}], ['control 2', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 3300}], ['control 3', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 200, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 4200, 'refund': 1000, 'suspense': 0, 'new_balance': 0}], ['control 4', {'due': {'interest': 1250, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 8250, 'suspense': 200, 'threshold': 3250, 'balance': 800}, {'applied': {'interest': 1250, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'curtailment': -1200, 'refund': 6400, 'suspense': 0, 'new_balance': 0}], ['control 5', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100}]], [['regression: threshold boundary', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['regression: threshold boundary, partial-repair probe', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': -1, 'suspense': 200, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 1', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 1300, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}], ['control 2', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 800, 'refund': 165, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 300, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100000}], ['control 4', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 2051, 'suspense': 200, 'threshold': 2050, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 98999}], ['control 5', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'curtailment': 1850, 'refund': 0, 'suspense': 0, 'new_balance': 150}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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)

prompt:
A payment exactly equal to the threshold is parked in suspense.

x = {'due': {'interest', 'principal', 'late_fee', 'fees'}, 'payment', 'suspense', 'threshold', 'balance'}. Available = payment + suspense. If available < threshold, everything goes to suspense and nothing is applied. Otherwise apply in order interest, principal, late_fee, fees, then curtail principal with the remainder up to balance - applied principal; the rest is refunded. Return {'applied', 'curtailment', 'refund', 'suspense', 'new_balance'}.

split: open-access


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

N = 1
observations = []
def solve(x):
    avail = x['payment'] + x['suspense']
    applied = {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}
    if avail < x['threshold']:
        return {'applied': applied, 'curtailment': 0, 'refund': 0, 'suspense': avail, 'new_balance': x['balance']}
    for k in ('principal', 'interest', 'late_fee', 'fees'):
        take = min(avail, x['due'][k])
        applied[k] = take
        avail -= take
    room = x['balance'] - applied['principal']
    curt = min(avail, room)
    refund = avail - curt
    return {'applied': applied, 'curtailment': curt, 'refund': refund, 'suspense': 0, 'new_balance': x['balance'] - applied['principal'] - curt}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: waterfall order', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4500}], ['regression: waterfall order, partial-repair probe', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 300, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4700}], ['control 1', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 2', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 7200, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 4000, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 0, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 800}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1250, 'suspense': 700, 'threshold': 1250, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 99300}], ['control 5', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1300, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}]], [['regression: waterfall order', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['regression: waterfall order, partial-repair probe', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 35}, 'payment': 0, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100}], ['control 1', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'curtailment': 165, 'refund': 0, 'suspense': 0, 'new_balance': 2835}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 950, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 350, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2201, 'suspense': 200, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 3999}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 649, 'suspense': 0, 'threshold': 650, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 649, 'new_balance': 100000}], ['control 5', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 0, 'refund': 1550, 'suspense': 0, 'new_balance': 0}]], [['regression: waterfall order', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['regression: waterfall order, partial-repair probe', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': -200, 'refund': 200, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4000}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'payment': 835, 'suspense': 0, 'threshold': 835, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4200}], ['control 3', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 0, 'threshold': 800, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 5000, 'refund': 0, 'suspense': 0, 'new_balance': 94200}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 499, 'suspense': 200, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 200, 'new_balance': 800}]], [['regression: waterfall order', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100}], ['regression: waterfall order, partial-repair probe', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 3300}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 36, 'suspense': 700, 'threshold': 35, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 701, 'refund': 0, 'suspense': 0, 'new_balance': 99}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 200, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 4200, 'refund': 1000, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 4', {'due': {'interest': 1250, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 8250, 'suspense': 200, 'threshold': 3250, 'balance': 800}, {'applied': {'interest': 1250, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'curtailment': -1200, 'refund': 6400, 'suspense': 0, 'new_balance': 0}], ['control 5', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 200, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 300}]], [['regression: waterfall order', {'due': {'interest': 1250, 'principal': 2000, 'late_fee': 150, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 1450, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 98550}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': -1, 'suspense': 200, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 2', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 1300, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 800, 'refund': 165, 'suspense': 0, 'new_balance': 0}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 300, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100000}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 6', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 2051, 'suspense': 200, 'threshold': 2050, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 98999}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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)

meaning: Fixture-count band, not measured model difficulty

deps: stdlib

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

N = 1
observations = []
def solve(x):
    avail = x['payment'] + x['suspense']
    applied = {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}
    if avail < x['threshold']:
        return {'applied': applied, 'curtailment': 0, 'refund': 0, 'suspense': avail, 'new_balance': x['balance']}
    for k in ('interest', 'late_fee', 'principal', 'fees'):
        take = min(avail, x['due'][k])
        applied[k] = take
        avail -= take
    room = x['balance'] - applied['principal']
    curt = min(avail, room)
    refund = avail - curt
    return {'applied': applied, 'curtailment': curt, 'refund': refund, 'suspense': 0, 'new_balance': x['balance'] - applied['principal'] - curt}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: waterfall order', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4500}], ['regression: waterfall order, partial-repair probe', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 300, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4700}], ['control 1', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 2', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 7200, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 4000, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 0, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 800}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1250, 'suspense': 700, 'threshold': 1250, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 99300}], ['control 5', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1300, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}]], [['regression: waterfall order', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['regression: waterfall order, partial-repair probe', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 35}, 'payment': 0, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100}], ['control 1', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'curtailment': 165, 'refund': 0, 'suspense': 0, 'new_balance': 2835}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 950, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 350, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2201, 'suspense': 200, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 3999}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 649, 'suspense': 0, 'threshold': 650, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 649, 'new_balance': 100000}], ['control 5', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 0, 'refund': 1550, 'suspense': 0, 'new_balance': 0}]], [['regression: waterfall order', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['regression: waterfall order, partial-repair probe', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': -200, 'refund': 200, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4000}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'payment': 835, 'suspense': 0, 'threshold': 835, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4200}], ['control 3', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 0, 'threshold': 800, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 5000, 'refund': 0, 'suspense': 0, 'new_balance': 94200}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 499, 'suspense': 200, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 200, 'new_balance': 800}]], [['regression: waterfall order', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100}], ['regression: waterfall order, partial-repair probe', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 3300}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 36, 'suspense': 700, 'threshold': 35, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 701, 'refund': 0, 'suspense': 0, 'new_balance': 99}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 200, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 4200, 'refund': 1000, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 4', {'due': {'interest': 1250, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 8250, 'suspense': 200, 'threshold': 3250, 'balance': 800}, {'applied': {'interest': 1250, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'curtailment': -1200, 'refund': 6400, 'suspense': 0, 'new_balance': 0}], ['control 5', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 200, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 300}]], [['regression: waterfall order', {'due': {'interest': 1250, 'principal': 2000, 'late_fee': 150, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 1450, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 98550}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': -1, 'suspense': 200, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 2', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 1300, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 800, 'refund': 165, 'suspense': 0, 'new_balance': 0}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 300, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100000}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 6', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 2051, 'suspense': 200, 'threshold': 2050, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 98999}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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)

prompt:
Short payments reduce principal while interest remains unpaid.

x = {'due': {'interest', 'principal', 'late_fee', 'fees'}, 'payment', 'suspense', 'threshold', 'balance'}. Available = payment + suspense. If available < threshold, everything goes to suspense and nothing is applied. Otherwise apply in order interest, principal, late_fee, fees, then curtail principal with the remainder up to balance - applied principal; the rest is refunded. Return {'applied', 'curtailment', 'refund', 'suspense', 'new_balance'}.

split: open-access


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

N = 1
observations = []
def solve(x):
    avail = x['payment'] + x['suspense']
    applied = {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}
    if avail < x['threshold']:
        return {'applied': applied, 'curtailment': 0, 'refund': 0, 'suspense': avail, 'new_balance': x['balance']}
    for k in ('interest', 'principal', 'late_fee', 'fees'):
        take = min(avail, x['due'][k])
        applied[k] = take
        avail -= take
    room = x['balance']
    curt = min(avail, room)
    refund = avail - curt
    return {'applied': applied, 'curtailment': curt, 'refund': refund, 'suspense': 0, 'new_balance': x['balance'] - applied['principal'] - curt}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: curtailment room', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 7200, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 4000, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 2', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 0, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 800}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1250, 'suspense': 700, 'threshold': 1250, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 99300}], ['control 4', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1300, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 5', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4500}], ['control 6', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1285, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}]], [['regression: curtailment room', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 950, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 350, 'suspense': 0, 'new_balance': 0}], ['regression: curtailment room, partial-repair probe', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'payment': 5835, 'suspense': 700, 'threshold': 835, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'curtailment': 1200, 'refund': 4500, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['control 2', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'curtailment': 165, 'refund': 0, 'suspense': 0, 'new_balance': 2835}], ['control 3', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2201, 'suspense': 200, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 3999}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 649, 'suspense': 0, 'threshold': 650, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 649, 'new_balance': 100000}], ['control 5', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1000, 'suspense': 0, 'threshold': 535, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 465, 'refund': 0, 'suspense': 0, 'new_balance': 1535}]], [['regression: curtailment room', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': -200, 'refund': 200, 'suspense': 0, 'new_balance': 0}], ['regression: curtailment room, partial-repair probe', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 6300, 'suspense': 0, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 4200, 'refund': 800, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4000}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'payment': 835, 'suspense': 0, 'threshold': 835, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4200}], ['control 3', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 0, 'threshold': 800, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 5000, 'refund': 0, 'suspense': 0, 'new_balance': 94200}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 499, 'suspense': 200, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 200, 'new_balance': 800}]], [['regression: curtailment room', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 200, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 4200, 'refund': 1000, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 36, 'suspense': 700, 'threshold': 35, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 701, 'refund': 0, 'suspense': 0, 'new_balance': 99}], ['control 2', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 3300}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 4', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100}], ['control 5', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 200, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 300}], ['control 6', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 2650, 'suspense': 0, 'threshold': 2650, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}]], [['regression: curtailment room', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 2000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'curtailment': -1200, 'refund': 1700, 'suspense': 0, 'new_balance': 0}], ['regression: curtailment room, partial-repair probe', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 800, 'refund': 165, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': -1, 'suspense': 200, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 2', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 1300, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 300, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100000}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 5', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 2051, 'suspense': 200, 'threshold': 2050, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 98999}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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)

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

N = 1
observations = []
def solve(x):
    avail = x['payment'] + x['suspense']
    applied = {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}
    if avail < x['threshold']:
        return {'applied': applied, 'curtailment': 0, 'refund': 0, 'suspense': avail, 'new_balance': x['balance']}
    for k in ('interest', 'principal', 'late_fee', 'fees'):
        take = min(avail, x['due'][k])
        applied[k] = take
        avail -= take
    room = x['balance'] - applied['principal'] if x['balance'] > avail else 0
    curt = min(avail, room)
    refund = avail - curt
    return {'applied': applied, 'curtailment': curt, 'refund': refund, 'suspense': 0, 'new_balance': x['balance'] - applied['principal'] - curt}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: curtailment room', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 7200, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 4000, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 2', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 0, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 800}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1250, 'suspense': 700, 'threshold': 1250, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 99300}], ['control 4', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1300, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 5', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4500}], ['control 6', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1285, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}]], [['regression: curtailment room', {'due': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 950, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 350, 'suspense': 0, 'new_balance': 0}], ['regression: curtailment room, partial-repair probe', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'payment': 5835, 'suspense': 700, 'threshold': 835, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'curtailment': 1200, 'refund': 4500, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['control 2', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'curtailment': 165, 'refund': 0, 'suspense': 0, 'new_balance': 2835}], ['control 3', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 2201, 'suspense': 200, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 3999}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 649, 'suspense': 0, 'threshold': 650, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 649, 'new_balance': 100000}], ['control 5', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1000, 'suspense': 0, 'threshold': 535, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 465, 'refund': 0, 'suspense': 0, 'new_balance': 1535}]], [['regression: curtailment room', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': -200, 'refund': 200, 'suspense': 0, 'new_balance': 0}], ['regression: curtailment room, partial-repair probe', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 6300, 'suspense': 0, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 4200, 'refund': 800, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4000}], ['control 2', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'payment': 835, 'suspense': 0, 'threshold': 835, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4200}], ['control 3', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 0, 'threshold': 800, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 5000, 'refund': 0, 'suspense': 0, 'new_balance': 94200}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 499, 'suspense': 200, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 200, 'new_balance': 800}]], [['regression: curtailment room', {'due': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 5800, 'suspense': 200, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 4200, 'refund': 1000, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 36, 'suspense': 700, 'threshold': 35, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 701, 'refund': 0, 'suspense': 0, 'new_balance': 99}], ['control 2', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 3300}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 4', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100}], ['control 5', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 200, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 300}], ['control 6', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 2650, 'suspense': 0, 'threshold': 2650, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}]], [['regression: curtailment room', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 2000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 2000, 'late_fee': 0, 'fees': 0}, 'curtailment': -1200, 'refund': 1700, 'suspense': 0, 'new_balance': 0}], ['regression: curtailment room, partial-repair probe', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 800, 'refund': 165, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': -1, 'suspense': 200, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 2', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 1300, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 300, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100000}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 5', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 2051, 'suspense': 200, 'threshold': 2050, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 201, 'refund': 0, 'suspense': 0, 'new_balance': 98999}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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)

prompt:
Overpayments near payoff drive the principal balance negative.

x = {'due': {'interest', 'principal', 'late_fee', 'fees'}, 'payment', 'suspense', 'threshold', 'balance'}. Available = payment + suspense. If available < threshold, everything goes to suspense and nothing is applied. Otherwise apply in order interest, principal, late_fee, fees, then curtail principal with the remainder up to balance - applied principal; the rest is refunded. Return {'applied', 'curtailment', 'refund', 'suspense', 'new_balance'}.

split: open-access


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

N = 1
observations = []
def solve(x):
    avail = x['payment'] + x['suspense']
    applied = {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}
    if avail < x['threshold']:
        return {'applied': applied, 'curtailment': 0, 'refund': 0, 'suspense': avail, 'new_balance': x['balance']}
    for k in ('interest', 'principal', 'late_fee', 'fees'):
        take = min(avail, x['due'][k])
        applied[k] = take
        avail -= take
    room = x['balance'] - applied['principal']
    curt = min(avail, room)
    refund = avail - curt
    return {'applied': applied, 'curtailment': curt, 'refund': refund, 'suspense': 0, 'new_balance': x['balance'] - curt}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: new balance reduction', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 7200, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 4000, 'suspense': 0, 'new_balance': 0}], ['regression: new balance reduction, partial-repair probe', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4500}], ['control 1', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 2', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 0, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 800}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1250, 'suspense': 700, 'threshold': 1250, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 99300}], ['control 4', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1300, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1285, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}]], [['regression: new balance reduction', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['control 1', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 649, 'suspense': 0, 'threshold': 650, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 649, 'new_balance': 100000}], ['control 2', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1000, 'suspense': 0, 'threshold': 535, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 465, 'refund': 0, 'suspense': 0, 'new_balance': 1535}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 0, 'suspense': 700, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 700, 'new_balance': 800}], ['control 4', {'due': {'interest': 0, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 151, 'suspense': 200, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 351, 'new_balance': 2000}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1285, 'suspense': 200, 'threshold': 1285, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 200, 'refund': 0, 'suspense': 0, 'new_balance': 4800}], ['control 6', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 700, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 200, 'refund': 0, 'suspense': 0, 'new_balance': 4800}]], [['regression: new balance reduction', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': -200, 'refund': 200, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 499, 'suspense': 200, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 2', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 200, 'new_balance': 800}], ['control 3', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 4300}], ['control 4', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 5035, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 5000, 'refund': 0, 'suspense': 0, 'new_balance': 95000}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 500, 'new_balance': 2000}], ['control 6', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 700, 'new_balance': 2000}]], [['regression: new balance reduction', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 3300}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 36, 'suspense': 700, 'threshold': 35, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 701, 'refund': 0, 'suspense': 0, 'new_balance': 99}], ['control 2', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1284, 'suspense': 700, 'threshold': 1000, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 699, 'refund': 0, 'suspense': 0, 'new_balance': 99301}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 534, 'suspense': 0, 'threshold': 535, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 534, 'new_balance': 100000}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1249, 'suspense': 700, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 699, 'refund': 0, 'suspense': 0, 'new_balance': 4301}], ['control 6', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 35}, 'payment': 2500, 'suspense': 700, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 35}, 'curtailment': 1765, 'refund': 0, 'suspense': 0, 'new_balance': 98235}]], [['regression: new balance reduction', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 1300, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}], ['regression: new balance reduction, partial-repair probe', {'due': {'interest': 1250, 'principal': 2000, 'late_fee': 150, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 1450, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 98550}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': -1, 'suspense': 200, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 2', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 800, 'refund': 165, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 300, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100000}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 5', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'curtailment': 1850, 'refund': 0, 'suspense': 0, 'new_balance': 150}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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)

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

N = 1
observations = []
def solve(x):
    avail = x['payment'] + x['suspense']
    applied = {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}
    if avail < x['threshold']:
        return {'applied': applied, 'curtailment': 0, 'refund': 0, 'suspense': avail, 'new_balance': x['balance']}
    for k in ('interest', 'principal', 'late_fee', 'fees'):
        take = min(avail, x['due'][k])
        applied[k] = take
        avail -= take
    room = x['balance'] - applied['principal']
    curt = min(avail, room)
    refund = avail - curt
    return {'applied': applied, 'curtailment': curt, 'refund': refund, 'suspense': 0, 'new_balance': x['balance'] - x['due']['principal'] - curt}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: new balance reduction', {'due': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'payment': 7200, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 800, 'late_fee': 150, 'fees': 0}, 'curtailment': 1200, 'refund': 4000, 'suspense': 0, 'new_balance': 0}], ['regression: new balance reduction, partial-repair probe', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 4500}], ['control 1', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 2', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 0, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 800}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1250, 'suspense': 700, 'threshold': 1250, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 99300}], ['control 4', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 1300, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 300, 'new_balance': 800}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1285, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}]], [['regression: new balance reduction', {'due': {'interest': 500, 'principal': 2000, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 500, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 1500}], ['control 1', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 649, 'suspense': 0, 'threshold': 650, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 649, 'new_balance': 100000}], ['control 2', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1000, 'suspense': 0, 'threshold': 535, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 465, 'refund': 0, 'suspense': 0, 'new_balance': 1535}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 0, 'suspense': 700, 'threshold': 1250, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 700, 'new_balance': 800}], ['control 4', {'due': {'interest': 0, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 151, 'suspense': 200, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 351, 'new_balance': 2000}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1285, 'suspense': 200, 'threshold': 1285, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 200, 'refund': 0, 'suspense': 0, 'new_balance': 4800}], ['control 6', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 700, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 200, 'refund': 0, 'suspense': 0, 'new_balance': 4800}]], [['regression: new balance reduction', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 1000, 'late_fee': 0, 'fees': 0}, 'curtailment': -200, 'refund': 200, 'suspense': 0, 'new_balance': 0}], ['control 1', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 499, 'suspense': 200, 'threshold': 500, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 2', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 200, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 200, 'new_balance': 800}], ['control 3', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 200, 'threshold': 0, 'balance': 5000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 700, 'refund': 0, 'suspense': 0, 'new_balance': 4300}], ['control 4', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 5035, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 5000, 'refund': 0, 'suspense': 0, 'new_balance': 95000}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 300, 'suspense': 200, 'threshold': 1250, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 500, 'new_balance': 2000}], ['control 6', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 0, 'suspense': 700, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 700, 'new_balance': 2000}]], [['regression: new balance reduction', {'due': {'interest': 0, 'principal': 2000, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 700, 'threshold': 1000, 'balance': 5000}, {'applied': {'interest': 0, 'principal': 1700, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 3300}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 36, 'suspense': 700, 'threshold': 35, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 701, 'refund': 0, 'suspense': 0, 'new_balance': 99}], ['control 2', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 1284, 'suspense': 700, 'threshold': 1000, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 699, 'refund': 0, 'suspense': 0, 'new_balance': 99301}], ['control 4', {'due': {'interest': 500, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 534, 'suspense': 0, 'threshold': 535, 'balance': 100000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 534, 'new_balance': 100000}], ['control 5', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1249, 'suspense': 700, 'threshold': 1250, 'balance': 5000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 699, 'refund': 0, 'suspense': 0, 'new_balance': 4301}], ['control 6', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 35}, 'payment': 2500, 'suspense': 700, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 35}, 'curtailment': 1765, 'refund': 0, 'suspense': 0, 'new_balance': 98235}]], [['regression: new balance reduction', {'due': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'payment': 1300, 'suspense': 0, 'threshold': 1000, 'balance': 800}, {'applied': {'interest': 500, 'principal': 800, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 0}], ['regression: new balance reduction, partial-repair probe', {'due': {'interest': 1250, 'principal': 2000, 'late_fee': 150, 'fees': 35}, 'payment': 2500, 'suspense': 200, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 1250, 'principal': 1450, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 98550}], ['control 1', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': -1, 'suspense': 200, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 199, 'refund': 0, 'suspense': 0, 'new_balance': 1801}], ['control 2', {'due': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'payment': 300, 'suspense': 700, 'threshold': 0, 'balance': 800}, {'applied': {'interest': 0, 'principal': 0, 'late_fee': 0, 'fees': 35}, 'curtailment': 800, 'refund': 165, 'suspense': 0, 'new_balance': 0}], ['control 3', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 300, 'suspense': 0, 'threshold': 0, 'balance': 100000}, {'applied': {'interest': 300, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 100000}], ['control 4', {'due': {'interest': 1250, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'payment': 1000, 'suspense': 0, 'threshold': 1000, 'balance': 2000}, {'applied': {'interest': 1000, 'principal': 0, 'late_fee': 0, 'fees': 0}, 'curtailment': 0, 'refund': 0, 'suspense': 0, 'new_balance': 2000}], ['control 5', {'due': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'payment': 2500, 'suspense': 0, 'threshold': 0, 'balance': 2000}, {'applied': {'interest': 500, 'principal': 0, 'late_fee': 150, 'fees': 0}, 'curtailment': 1850, 'refund': 0, 'suspense': 0, 'new_balance': 150}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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)

prompt:
Scheduled principal payments do not lower the reported balance.

x = {'due': {'interest', 'principal', 'late_fee', 'fees'}, 'payment', 'suspense', 'threshold', 'balance'}. Available = payment + suspense. If available < threshold, everything goes to suspense and nothing is applied. Otherwise apply in order interest, principal, late_fee, fees, then curtail principal with the remainder up to balance - applied principal; the rest is refunded. Return {'applied', 'curtailment', 'refund', 'suspense', 'new_balance'}.

split: open-access