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

N = 1
observations = []
def solve(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': pass
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+i)%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=0
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+i)%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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 new subpath inherits the previous subpath dash phase.

A logical stroke has positive integer dash lengths; an odd-length dash array is duplicated to preserve on/off parity over cycles. Each draw advances path phase through all samples, including clipped samples. Move begins a new subpath at the configured offset. Changing offset affects the next move, while changing pattern resets phase immediately. Empty pattern means solid. Draw reports visible on-sample positions within that segment.

split: open-access


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

N = 1
observations = []
def solve(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': pass
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+i)%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+i)%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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:
Skipped stroke distance does not advance dash phase.

A logical stroke has positive integer dash lengths; an odd-length dash array is duplicated to preserve on/off parity over cycles. Each draw advances path phase through all samples, including clipped samples. Move begins a new subpath at the configured offset. Changing offset affects the next move, while changing pattern resets phase immediately. Empty pattern means solid. Draw reports visible on-sample positions within that segment.

split: open-access


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

N = 1
observations = []
def solve(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+i)%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=len(covered)
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+i)%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=len(visible)
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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:
Clipped-out and off-dash samples are omitted from path phase advancement.

A logical stroke has positive integer dash lengths; an odd-length dash array is duplicated to preserve on/off parity over cycles. Each draw advances path phase through all samples, including clipped samples. Move begins a new subpath at the configured offset. Changing offset affects the next move, while changing pattern resets phase immediately. Empty pattern means solid. Draw reports visible on-sample positions within that segment.

split: open-access


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

N = 1
observations = []
def solve(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+i)%sum(pattern)
                    dash=0
                    while position>pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+i)%sum(pattern)
                    dash=0
                    while dash+1<len(pattern) and position+1>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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:
An exact dash boundary is assigned to the preceding run.

A logical stroke has positive integer dash lengths; an odd-length dash array is duplicated to preserve on/off parity over cycles. Each draw advances path phase through all samples, including clipped samples. Move begins a new subpath at the configured offset. Changing offset affects the next move, while changing pattern resets phase immediately. Empty pattern means solid. Draw reports visible on-sample positions within that segment.

split: open-access


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

N = 1
observations = []
def solve(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(i-phase)%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(abs(phase)+i)%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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:
The configured phase is subtracted instead of added before dash lookup.

A logical stroke has positive integer dash lengths; an odd-length dash array is duplicated to preserve on/off parity over cycles. Each draw advances path phase through all samples, including clipped samples. Move begins a new subpath at the configured offset. Changing offset affects the next move, while changing pattern resets phase immediately. Empty pattern means solid. Draw reports visible on-sample positions within that segment.

split: open-access


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

N = 1
observations = []
def solve(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=phase%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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(commands, size):
    pattern=[]
    offset=0
    phase=0
    out=[]
    for cmd in commands:
        op=cmd[0]
        if op=='pattern':
            pattern=list(cmd[1])
            if len(pattern)%2: pattern=pattern*2
            phase=offset
        elif op=='offset': offset=cmd[1]
        elif op=='move': phase=offset
        elif op=='advance': phase+=cmd[1]
        elif op=='draw':
            length,visible=cmd[1],set(cmd[2])
            covered=[]
            for i in range(length):
                on=True
                if pattern:
                    position=(phase+min(i,1))%sum(pattern)
                    dash=0
                    while position>=pattern[dash]:
                        position-=pattern[dash]
                        dash+=1
                    on=dash%2==0
                if on and i in visible and 0<=i<size: covered.append(i)
            phase+=length
            out.append(covered)
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
if N == 1:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 4), [[0, 2]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 4), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 4), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 4), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 4), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 4), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 4), [[0, 1, 2, 3], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 4), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 4), [[]])
if N == 2:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 5), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 5), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 5), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 5), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 5), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 5), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 5), [[0, 1, 2, 3, 4], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 5), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 5), [[]])
if N == 3:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 6), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 6), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 6), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 6), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 6), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 6), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 6), [[0, 1, 2, 3, 4, 5], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 6), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 6), [[]])
if N == 4:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 7), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 7), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 7), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 7), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 7), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 7), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 7), [[0, 1, 2, 3, 4, 5, 6], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 7), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 7), [[]])
if N == 5:
    check('explicit sequence 0', solve([['pattern', [1, 1, 1]], ['draw', 6, [0, 1, 2, 3, 4, 5]]], 8), [[0, 2, 4]])
    check('explicit sequence 1', solve([['offset', -1], ['pattern', [2, 1]], ['draw', 4, [0, 1, 2, 3]]], 8), [[1, 2]])
    check('explicit sequence 2', solve([['pattern', [2, 1]], ['draw', 1, [0]], ['offset', 2], ['draw', 3, [0, 1, 2]]], 8), [[0], [0, 2]])
    check('explicit sequence 3', solve([['offset', 1], ['pattern', [2, 2]], ['draw', 2, [0, 1]], ['move'], ['draw', 3, [0, 1, 2]]], 8), [[0], [0]])
    check('explicit sequence 4', solve([['pattern', [2, 2]], ['draw', 1, [0]], ['advance', 1], ['draw', 3, [0, 1, 2]]], 8), [[0], [2]])
    check('explicit sequence 5', solve([['pattern', [2, 2]], ['draw', 3, [0]], ['draw', 3, [0, 1, 2]]], 8), [[0], [1, 2]])
    check('explicit sequence 6', solve([['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[0, 3]])
    check('explicit sequence 7', solve([['pattern', []], ['draw', 10, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]], ['draw', 2, [0, 1]]], 8), [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1]])
    check('explicit sequence 8', solve([['offset', 1], ['pattern', [1, 2]], ['draw', 4, [0, 1, 2, 3]]], 8), [[2]])
    check('explicit sequence 9', solve([['pattern', [1, 1]], ['draw', 0, []]], 8), [[]])
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:
All samples in a draw share the first sample dash decision.

A logical stroke has positive integer dash lengths; an odd-length dash array is duplicated to preserve on/off parity over cycles. Each draw advances path phase through all samples, including clipped samples. Move begins a new subpath at the configured offset. Changing offset affects the next move, while changing pattern resets phase immediately. Empty pattern means solid. Draw reports visible on-sample positions within that segment.

split: open-access