FA-95576 / Shipping rate zone lookup / Open access

Injection zone: distance truncated · case 01

Destinations a fraction of a mile past a band edge are rated in the cheaper zone.

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

ROOT CAUSE

Distance uses the integer square root without rounding up the remainder.

VERIFIED REPAIR

Round the straight-line distance up to a whole mile.

Unsuccessful approach: Rounding to nearest keeps distances just over a band in the lower zone.

Case contract

dest [x, y] and points [[name, x, y, linehaul_cents]] on a mile grid. Distance = straight line rounded up to a whole mile. Zone bands (miles, inclusive upper): 50, 150, 300, 600, 1000, 1400, 1800 -> zones 1-7, beyond -> 8. Choose the point with the lowest zone, then linehaul, then name. Return [name, zone, miles] or None.

Why this case matters

Zone skipping injects parcels at the hub that minimizes delivery zone and linehaul.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(dest, points):
    BANDS = [50, 150, 300, 600, 1000, 1400, 1800]
    def zone_for(m):
        for i, lim in enumerate(BANDS):
            if m <= lim:
                return i + 1
        return 8
    best = None
    for name, x, y, lh in points:
        sq = (x - dest[0]) ** 2 + (y - dest[1]) ** 2
        s = math.isqrt(sq)
        miles = s
        z = zone_for(miles)
        key = (z, lh, name)
        if best is None or key < best[0]:
            best = (key, [name, z, miles])
    return best[1] if best else None
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['generated mix 4', [[0, 3], [['IL', 301, 41, 300]]], ['IL', 4, 304]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['generated mix 7', [[5, 3], [['NJ', 0, 41, 300], ['NJ', 100, 400, 300], ['NJ', 0, 0, 100]]], ['NJ', 1, 6]], ['generated mix 15', [[5, 0], [['IL', 30, 40, 300], ['IL', 1500, 150, 300]]], ['IL', 1, 48]]], [['generated mix 8', [[5, 0], [['GA', 300, 40, 300]]], ['GA', 3, 298]], ['generated mix 19', [[5, 0], [['OH', 40, 1, 900], ['NJ', 2000, 150, 100], ['IL', 290, 0, 100], ['NJ', 40, 400, 100]]], ['OH', 1, 36]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['generated mix 10', [[5, 0], [['GA', 2000, 400, 900], ['IL', 1500, 41, 300]]], ['IL', 7, 1496]], ['generated mix 18', [[5, 3], [['IL', 30, 41, 300], ['IL', 120, 400, 300]]], ['IL', 1, 46]]], [['generated mix 18', [[5, 3], [['IL', 30, 41, 300], ['IL', 120, 400, 300]]], ['IL', 1, 46]], ['generated mix 25', [[0, 0], [['GA', 30, 1, 300]]], ['GA', 1, 31]], ['no points', [[0, 0], []], None], ['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['generated mix 21', [[5, 0], [['GA', 590, 41, 100], ['GA', 1500, 400, 900], ['PA', 100, 1, 100], ['GA', 2000, 40, 100]]], ['PA', 2, 96]], ['generated mix 30', [[-10, 3], [['OH', 0, 41, 300], ['PA', 300, 1, 300], ['NJ', 290, 40, 300]]], ['OH', 1, 40]]], [['generated mix 25', [[0, 0], [['GA', 30, 1, 300]]], ['GA', 1, 31]], ['generated mix 32', [[-10, 0], [['TX', 0, 1, 300], ['TX', 120, 40, 100], ['GA', 40, 400, 900]]], ['TX', 1, 11]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['name tiebreak', [[0, 0], [['Z', 10, 0, 100], ['M', 0, 10, 100]]], ['M', 1, 10]], ['no points', [[0, 0], []], None], ['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['generated mix 33', [[0, 3], [['GA', 1500, 150, 900], ['OH', 30, 1, 300]]], ['OH', 1, 31]], ['generated mix 41', [[0, 3], [['OH', 30, 0, 300], ['PA', 1500, 0, 300]]], ['OH', 1, 31]]], [['generated mix 32', [[-10, 0], [['TX', 0, 1, 300], ['TX', 120, 40, 100], ['GA', 40, 400, 900]]], ['TX', 1, 11]], ['generated mix 41', [[0, 3], [['OH', 30, 0, 300], ['PA', 1500, 0, 300]]], ['OH', 1, 31]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['name tiebreak', [[0, 0], [['Z', 10, 0, 100], ['M', 0, 10, 100]]], ['M', 1, 10]], ['generated mix 44', [[0, 3], [['NJ', 590, 1, 300], ['PA', 300, 40, 900]]], ['NJ', 4, 591]], ['generated mix 52', [[-10, 0], [['IL', 290, 400, 300]]], ['IL', 4, 500]]]]
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
just over	`['A', 1, 50]`	`['A', 2, 51]`	Failed
generated mix 4	`['IL', 4, 303]`	`['IL', 4, 304]`	Failed
exact 50 miles	`['A', 1, 50]`	`['A', 1, 50]`	Passed
zone beats linehaul	`['A', 1, 40]`	`['A', 1, 40]`	Passed
far	`['A', 8, 2000]`	`['A', 8, 2000]`	Passed
linehaul tiebreak	`['B', 2, 120]`	`['B', 2, 120]`	Passed
generated mix 7	`['NJ', 1, 5]`	`['NJ', 1, 6]`	Failed
generated mix 15	`['IL', 1, 47]`	`['IL', 1, 48]`	Failed

SHA-256 / 888435d5ffde89affb8690ad3d8d1ce94f779341b7b7ed748b6cd1798b452eb3

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(dest, points):
    BANDS = [50, 150, 300, 600, 1000, 1400, 1800]
    def zone_for(m):
        for i, lim in enumerate(BANDS):
            if m <= lim:
                return i + 1
        return 8
    best = None
    for name, x, y, lh in points:
        sq = (x - dest[0]) ** 2 + (y - dest[1]) ** 2
        s = math.isqrt(sq)
        miles = round(sq ** 0.5)
        z = zone_for(miles)
        key = (z, lh, name)
        if best is None or key < best[0]:
            best = (key, [name, z, miles])
    return best[1] if best else None
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['generated mix 4', [[0, 3], [['IL', 301, 41, 300]]], ['IL', 4, 304]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['generated mix 7', [[5, 3], [['NJ', 0, 41, 300], ['NJ', 100, 400, 300], ['NJ', 0, 0, 100]]], ['NJ', 1, 6]], ['generated mix 15', [[5, 0], [['IL', 30, 40, 300], ['IL', 1500, 150, 300]]], ['IL', 1, 48]]], [['generated mix 8', [[5, 0], [['GA', 300, 40, 300]]], ['GA', 3, 298]], ['generated mix 19', [[5, 0], [['OH', 40, 1, 900], ['NJ', 2000, 150, 100], ['IL', 290, 0, 100], ['NJ', 40, 400, 100]]], ['OH', 1, 36]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['generated mix 10', [[5, 0], [['GA', 2000, 400, 900], ['IL', 1500, 41, 300]]], ['IL', 7, 1496]], ['generated mix 18', [[5, 3], [['IL', 30, 41, 300], ['IL', 120, 400, 300]]], ['IL', 1, 46]]], [['generated mix 18', [[5, 3], [['IL', 30, 41, 300], ['IL', 120, 400, 300]]], ['IL', 1, 46]], ['generated mix 25', [[0, 0], [['GA', 30, 1, 300]]], ['GA', 1, 31]], ['no points', [[0, 0], []], None], ['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['generated mix 21', [[5, 0], [['GA', 590, 41, 100], ['GA', 1500, 400, 900], ['PA', 100, 1, 100], ['GA', 2000, 40, 100]]], ['PA', 2, 96]], ['generated mix 30', [[-10, 3], [['OH', 0, 41, 300], ['PA', 300, 1, 300], ['NJ', 290, 40, 300]]], ['OH', 1, 40]]], [['generated mix 25', [[0, 0], [['GA', 30, 1, 300]]], ['GA', 1, 31]], ['generated mix 32', [[-10, 0], [['TX', 0, 1, 300], ['TX', 120, 40, 100], ['GA', 40, 400, 900]]], ['TX', 1, 11]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['name tiebreak', [[0, 0], [['Z', 10, 0, 100], ['M', 0, 10, 100]]], ['M', 1, 10]], ['no points', [[0, 0], []], None], ['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['generated mix 33', [[0, 3], [['GA', 1500, 150, 900], ['OH', 30, 1, 300]]], ['OH', 1, 31]], ['generated mix 41', [[0, 3], [['OH', 30, 0, 300], ['PA', 1500, 0, 300]]], ['OH', 1, 31]]], [['generated mix 32', [[-10, 0], [['TX', 0, 1, 300], ['TX', 120, 40, 100], ['GA', 40, 400, 900]]], ['TX', 1, 11]], ['generated mix 41', [[0, 3], [['OH', 30, 0, 300], ['PA', 1500, 0, 300]]], ['OH', 1, 31]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['name tiebreak', [[0, 0], [['Z', 10, 0, 100], ['M', 0, 10, 100]]], ['M', 1, 10]], ['generated mix 44', [[0, 3], [['NJ', 590, 1, 300], ['PA', 300, 40, 900]]], ['NJ', 4, 591]], ['generated mix 52', [[-10, 0], [['IL', 290, 400, 300]]], ['IL', 4, 500]]]]
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
just over	`['A', 2, 51]`	`['A', 2, 51]`	Passed
generated mix 4	`['IL', 4, 303]`	`['IL', 4, 304]`	Failed
exact 50 miles	`['A', 1, 50]`	`['A', 1, 50]`	Passed
zone beats linehaul	`['A', 1, 40]`	`['A', 1, 40]`	Passed
far	`['A', 8, 2000]`	`['A', 8, 2000]`	Passed
linehaul tiebreak	`['B', 2, 120]`	`['B', 2, 120]`	Passed
generated mix 7	`['NJ', 1, 6]`	`['NJ', 1, 6]`	Passed
generated mix 15	`['IL', 1, 47]`	`['IL', 1, 48]`	Failed

SHA-256 / 2d774b87715b3160736ed36eae0194d2322dee60eaef12e1a1ce105fc569ab64

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(dest, points):
    BANDS = [50, 150, 300, 600, 1000, 1400, 1800]
    def zone_for(m):
        for i, lim in enumerate(BANDS):
            if m <= lim:
                return i + 1
        return 8
    best = None
    for name, x, y, lh in points:
        sq = (x - dest[0]) ** 2 + (y - dest[1]) ** 2
        s = math.isqrt(sq)
        miles = s + (1 if s * s < sq else 0)
        z = zone_for(miles)
        key = (z, lh, name)
        if best is None or key < best[0]:
            best = (key, [name, z, miles])
    return best[1] if best else None
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['generated mix 4', [[0, 3], [['IL', 301, 41, 300]]], ['IL', 4, 304]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['generated mix 7', [[5, 3], [['NJ', 0, 41, 300], ['NJ', 100, 400, 300], ['NJ', 0, 0, 100]]], ['NJ', 1, 6]], ['generated mix 15', [[5, 0], [['IL', 30, 40, 300], ['IL', 1500, 150, 300]]], ['IL', 1, 48]]], [['generated mix 8', [[5, 0], [['GA', 300, 40, 300]]], ['GA', 3, 298]], ['generated mix 19', [[5, 0], [['OH', 40, 1, 900], ['NJ', 2000, 150, 100], ['IL', 290, 0, 100], ['NJ', 40, 400, 100]]], ['OH', 1, 36]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['generated mix 10', [[5, 0], [['GA', 2000, 400, 900], ['IL', 1500, 41, 300]]], ['IL', 7, 1496]], ['generated mix 18', [[5, 3], [['IL', 30, 41, 300], ['IL', 120, 400, 300]]], ['IL', 1, 46]]], [['generated mix 18', [[5, 3], [['IL', 30, 41, 300], ['IL', 120, 400, 300]]], ['IL', 1, 46]], ['generated mix 25', [[0, 0], [['GA', 30, 1, 300]]], ['GA', 1, 31]], ['no points', [[0, 0], []], None], ['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['zone beats linehaul', [[0, 0], [['A', 40, 0, 900], ['B', 0, 120, 300]]], ['A', 1, 40]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['generated mix 21', [[5, 0], [['GA', 590, 41, 100], ['GA', 1500, 400, 900], ['PA', 100, 1, 100], ['GA', 2000, 40, 100]]], ['PA', 2, 96]], ['generated mix 30', [[-10, 3], [['OH', 0, 41, 300], ['PA', 300, 1, 300], ['NJ', 290, 40, 300]]], ['OH', 1, 40]]], [['generated mix 25', [[0, 0], [['GA', 30, 1, 300]]], ['GA', 1, 31]], ['generated mix 32', [[-10, 0], [['TX', 0, 1, 300], ['TX', 120, 40, 100], ['GA', 40, 400, 900]]], ['TX', 1, 11]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['name tiebreak', [[0, 0], [['Z', 10, 0, 100], ['M', 0, 10, 100]]], ['M', 1, 10]], ['no points', [[0, 0], []], None], ['just over', [[0, 0], [['A', 30, 41, 500]]], ['A', 2, 51]], ['generated mix 33', [[0, 3], [['GA', 1500, 150, 900], ['OH', 30, 1, 300]]], ['OH', 1, 31]], ['generated mix 41', [[0, 3], [['OH', 30, 0, 300], ['PA', 1500, 0, 300]]], ['OH', 1, 31]]], [['generated mix 32', [[-10, 0], [['TX', 0, 1, 300], ['TX', 120, 40, 100], ['GA', 40, 400, 900]]], ['TX', 1, 11]], ['generated mix 41', [[0, 3], [['OH', 30, 0, 300], ['PA', 1500, 0, 300]]], ['OH', 1, 31]], ['far', [[0, 0], [['A', 2000, 0, 1]]], ['A', 8, 2000]], ['exact 50 miles', [[0, 0], [['A', 30, 40, 500]]], ['A', 1, 50]], ['linehaul tiebreak', [[0, 0], [['A', 100, 0, 900], ['B', 0, 120, 300]]], ['B', 2, 120]], ['name tiebreak', [[0, 0], [['Z', 10, 0, 100], ['M', 0, 10, 100]]], ['M', 1, 10]], ['generated mix 44', [[0, 3], [['NJ', 590, 1, 300], ['PA', 300, 40, 900]]], ['NJ', 4, 591]], ['generated mix 52', [[-10, 0], [['IL', 290, 400, 300]]], ['IL', 4, 500]]]]
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
just over	`['A', 2, 51]`	`['A', 2, 51]`	Passed
generated mix 4	`['IL', 4, 304]`	`['IL', 4, 304]`	Passed
exact 50 miles	`['A', 1, 50]`	`['A', 1, 50]`	Passed
zone beats linehaul	`['A', 1, 40]`	`['A', 1, 40]`	Passed
far	`['A', 8, 2000]`	`['A', 8, 2000]`	Passed
linehaul tiebreak	`['B', 2, 120]`	`['B', 2, 120]`	Passed
generated mix 7	`['NJ', 1, 6]`	`['NJ', 1, 6]`	Passed
generated mix 15	`['IL', 1, 48]`	`['IL', 1, 48]`	Passed

SHA-256 / c55b590d29d2f0b9d0a18d0e36cf5b59d5da5334b23213a79d1322dc23a1d3c7

Verification & scope

Grid distance stand-in; not geodesic distances. 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 2026-09-29T14:52:14.913643+00:00.

Case digest / ec47822dcff233fb8cb960c1e2d57d6258204f508ec3450c0757e312a6320eaa