FA-95366 / Shipping rate zone lookup / Open access

Zone chart: garbage after ZIP3 accepted · case 01

Codes like "123AB" are rated as if they were valid ZIPs.

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

ROOT CAUSE

Validation only checks that the first three characters are digits.

VERIFIED REPAIR

Require all five characters to be decimal digits.

Unsuccessful approach: An alphanumeric test accepts letters in any position.

Case contract

dest is a ZIP string with optional surrounding whitespace, optionally ZIP+4 ("12345-6789"), or a 4-digit ZIP whose leading zero was lost (left-pad one zero). chart [[lo3, hi3, zone]] inclusive ZIP3 ranges; the narrowest matching range wins, earliest listed on equal width. Malformed -> "INVALID"; no match -> "NO_ZONE".

Why this case matters

Carrier zone charts map origin to destination ZIP3 ranges, the first step of rating.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(dest, chart):
    z = dest.strip()
    if len(z) == 10 and z[5] == '-' and z[6:].isdecimal():
        z = z[:5]
    if len(z) == 4 and z.isdecimal():
        z = '0' + z
    if len(z) != 5 or not z[:3].isdecimal():
        return 'INVALID'
    p = int(z[:3])
    best = None
    for lo, hi, zone in chart:
        if lo <= p <= hi:
            if best is None or (hi - lo) < (best[1] - best[0]):
                best = (lo, hi, zone)
    return best[2] if best else 'NO_ZONE'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 4', ['10001-12a4', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 7', ['09999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 16', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE']], [['generated mix 30', ['999x1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 17', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 25', ['15999-123', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 34', ['15000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4]], [['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['generated mix 30', ['999x1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8]], [['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 41', ['00501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 49', ['10001', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
letters	`5`	`INVALID`	Failed
generated mix 9	`8`	`INVALID`	Failed
zip plus four	`4`	`4`	Passed
range upper edge	`5`	`5`	Passed
equal width first listed	`2`	`2`	Passed
equal width plus four	`7`	`7`	Passed
lost leading zero	`8`	`8`	Passed
generated mix 4	`INVALID`	`INVALID`	Passed

SHA-256 / cc86718dff2b028dcbdebb77b443fe441c21cdffe181791021e270cd28ee965d

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(dest, chart):
    z = dest.strip()
    if len(z) == 10 and z[5] == '-' and z[6:].isdecimal():
        z = z[:5]
    if len(z) == 4 and z.isdecimal():
        z = '0' + z
    if len(z) != 5 or not z.replace(' ', '').isalnum():
        return 'INVALID'
    p = int(z[:3])
    best = None
    for lo, hi, zone in chart:
        if lo <= p <= hi:
            if best is None or (hi - lo) < (best[1] - best[0]):
                best = (lo, hi, zone)
    return best[2] if best else 'NO_ZONE'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 4', ['10001-12a4', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 7', ['09999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 16', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE']], [['generated mix 30', ['999x1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 17', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 25', ['15999-123', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 34', ['15000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4]], [['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['generated mix 30', ['999x1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8]], [['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 41', ['00501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 49', ['10001', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
letters	`5`	`INVALID`	Failed
generated mix 9	`8`	`INVALID`	Failed
zip plus four	`4`	`4`	Passed
range upper edge	`5`	`5`	Passed
equal width first listed	`2`	`2`	Passed
equal width plus four	`7`	`7`	Passed
lost leading zero	`8`	`8`	Passed
generated mix 4	`INVALID`	`INVALID`	Passed

SHA-256 / d14fdfcf1657dec3c3d07a97c952a0ae03399c6e465f6abc540a87e0007338d4

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(dest, chart):
    z = dest.strip()
    if len(z) == 10 and z[5] == '-' and z[6:].isdecimal():
        z = z[:5]
    if len(z) == 4 and z.isdecimal():
        z = '0' + z
    if len(z) != 5 or not z.isdecimal():
        return 'INVALID'
    p = int(z[:3])
    best = None
    for lo, hi, zone in chart:
        if lo <= p <= hi:
            if best is None or (hi - lo) < (best[1] - best[0]):
                best = (lo, hi, zone)
    return best[2] if best else 'NO_ZONE'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 4', ['10001-12a4', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 7', ['09999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 16', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE']], [['generated mix 30', ['999x1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 17', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 25', ['15999-123', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 34', ['15000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4]], [['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['generated mix 30', ['999x1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8]], [['generated mix 9', ['021 1', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 41', ['00501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 49', ['10001', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
letters	`INVALID`	`INVALID`	Passed
generated mix 9	`INVALID`	`INVALID`	Passed
zip plus four	`4`	`4`	Passed
range upper edge	`5`	`5`	Passed
equal width first listed	`2`	`2`	Passed
equal width plus four	`7`	`7`	Passed
lost leading zero	`8`	`8`	Passed
generated mix 4	`INVALID`	`INVALID`	Passed

SHA-256 / 0de14d232406efd0978d9a3e7394a7faa17375058f0e8a59cdbe08588595a84c

Verification & scope

Stipulated chart rows and input normalization; not a carrier-published chart. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:52:12.998422+00:00.

Case digest / 9679b613445b6a9c6af66b98f14a6466dba21187d9c73534be7bb7dbc97009f4