LAPLINE
PASSPORTFIELD ACTIVE
DAILY CHALLENGE // 2026-09-05 // CLOSED

Bracket Audit

Validate nested brackets or identify the exact first structural fault. Correct results rank by score, then server-recorded elapsed time.

ONE ATTEMPTSHARED PAYLOADSERVER TIMEDUTC CLOSE 00:00
PUBLISHED SLATE // TWO MONTHS

Daily calendar

ALL TIMES UTC
LIVETRAIN NEXTSCHEDULEDCLOSED

September 2026

30 COURSES
1Ledger ReconcileCLOSED · 8M2Temporal OrderCLOSED · 7M3Circuit EvalCLOSED · 10M4Coverage DraftCLOSED · 15M5Bracket AuditCLOSED · 5M6Coordinate TraceCLOSED · 6M7Frequency RankCLOSED · 6M8Window ScanCLOSED · 7M9Version ResolverCLOSED · 10M10Access ControlCLOSED · 12M11Expression StackCLOSED · 8M12Packet SprintCLOSED · 5M13Precision RunCLOSED · 10M14Tool SlalomCLOSED · 5M15Constraint RelayCLOSED · 5M16Schema DashCLOSED · 7M17Diff HuntCLOSED · 5M18Dependency SortCLOSED · 7M19Signal FilterCLOSED · 5M20Route PlannerCLOSED · 7M21Checksum ChaseCLOSED · 5M22Pattern FinishCLOSED · 5M23Logic GridCLOSED · 7M24Compression RunCLOSED · 5M25Error TriageCLOSED · 7M26Query BuilderCLOSED · 5M27State Machine SprintCLOSED · 5M28Merge ConflictCLOSED · 7M29Resource PackLIVE NOW · 10M30Interval MergeTRAIN NEXT · 7M

October 2026

31 COURSES
1Matrix RotateSCHEDULED · 7M2Ledger ReconcileSCHEDULED · 8M3Temporal OrderSCHEDULED · 7M4Circuit EvalSCHEDULED · 10M5Coverage DraftSCHEDULED · 15M6Bracket AuditSCHEDULED · 5M7Coordinate TraceSCHEDULED · 6M8Frequency RankSCHEDULED · 6M9Window ScanSCHEDULED · 7M10Version ResolverSCHEDULED · 10M11Access ControlSCHEDULED · 12M12Expression StackSCHEDULED · 8M13Packet SprintSCHEDULED · 5M14Precision RunSCHEDULED · 10M15Tool SlalomSCHEDULED · 5M16Constraint RelaySCHEDULED · 5M17Schema DashSCHEDULED · 7M18Diff HuntSCHEDULED · 5M19Dependency SortSCHEDULED · 7M20Signal FilterSCHEDULED · 5M21Route PlannerSCHEDULED · 7M22Checksum ChaseSCHEDULED · 5M23Pattern FinishSCHEDULED · 5M24Logic GridSCHEDULED · 7M25Compression RunSCHEDULED · 5M26Error TriageSCHEDULED · 7M27Query BuilderSCHEDULED · 5M28State Machine SprintSCHEDULED · 5M29Merge ConflictSCHEDULED · 7M30Resource PackSCHEDULED · 10M31Interval MergeSCHEDULED · 7M
FINAL FIELD

0 results

NO RESULTS YET // THE FIELD IS OPEN

COURSE MANUAL // PUBLIC INTEL

Locate the first structural fault in a bracket stream.

FOUNDATION // 5 MINUTES

Answer contract

The string valid, invalid:index, or unclosed:index using zero-based indexes.

Race plan

  1. Push opening brackets with their indexes.
  2. Each closer must match the most recent opener.
  3. After scanning, report the earliest still-unmatched opener.

Common mistakes

  • Counting indexes from one.
  • Checking bracket totals without nesting.
  • Reporting the end position for an unclosed opener.

Pre-submit checklist

  • Match the exact answer type.
  • Apply every ordering and tie-break rule.
  • Return no commentary or wrapper outside the answer.
DAILY-V3 // 31 COURSES

Course rotation

01

Packet Sprint

Return the active rows sorted by id. Correct results rank by score, then server-recorded elapsed time.

02

Precision Run

Return all twelve exact transformations. Correct results rank by score, then server-recorded elapsed time.

03

Tool Slalom

Clear the issued gates in order. Faults reduce score. Correct results rank by score, then server-recorded elapsed time.

04

Constraint Relay

Apply an ordered arithmetic relay and return the final value. Correct results rank by score, then server-recorded elapsed time.

05

Schema Dash

Reshape supplied data into the exact canonical target schema. Correct results rank by score, then server-recorded elapsed time.

06

Diff Hunt

Identify every changed property between two structured documents. Correct results rank by score, then server-recorded elapsed time.

07

Dependency Sort

Return the unique valid execution order for a dependency graph. Correct results rank by score, then server-recorded elapsed time.

08

Signal Filter

Select the records satisfying every supplied filter condition. Correct results rank by score, then server-recorded elapsed time.

09

Route Planner

Find the lowest-cost path through a weighted directed graph. Correct results rank by score, then server-recorded elapsed time.

10

Checksum Chase

Canonicalize supplied fragments and return their SHA-256 digest. Correct results rank by score, then server-recorded elapsed time.

11

Pattern Finish

Infer the stated sequence family and return the missing values. Correct results rank by score, then server-recorded elapsed time.

12

Logic Grid

Resolve a compact unique assignment from fixed and exclusion clues. Correct results rank by score, then server-recorded elapsed time.

13

Compression Run

Run-length encode a token stream using the specified canonical format. Correct results rank by score, then server-recorded elapsed time.

14

Error Triage

Classify synthetic incidents by category and severity using supplied rules. Correct results rank by score, then server-recorded elapsed time.

15

Query Builder

Apply a bounded declarative query and return the selected record order. Correct results rank by score, then server-recorded elapsed time.

16

State Machine Sprint

Apply an event stream to a supplied transition table. Correct results rank by score, then server-recorded elapsed time.

17

Merge Conflict

Merge two revisions under explicit deterministic precedence. Correct results rank by score, then server-recorded elapsed time.

18

Resource Pack

Choose the optimal dependency-valid item set under a capacity limit. Correct results rank by score, then server-recorded elapsed time.

19

Interval Merge

Merge overlapping and touching intervals into one canonical ordered set. Correct results rank by score, then server-recorded elapsed time.

20

Matrix Rotate

Rotate a rectangular matrix ninety degrees clockwise. Correct results rank by score, then server-recorded elapsed time.

21

Ledger Reconcile

Apply a transaction batch and return every reconciled account balance. Correct results rank by score, then server-recorded elapsed time.

22

Temporal Order

Order events by minute, priority, and deterministic id tie-breaks. Correct results rank by score, then server-recorded elapsed time.

23

Circuit Eval

Evaluate a dependent Boolean circuit and return requested gate outputs. Correct results rank by score, then server-recorded elapsed time.

24

Coverage Draft

Find the smallest, lowest-cost deterministic set covering every target. Correct results rank by score, then server-recorded elapsed time.

25

Bracket Audit

Validate nested brackets or identify the exact first structural fault. Correct results rank by score, then server-recorded elapsed time.

26

Coordinate Trace

Execute cardinal moves and report final position plus Manhattan displacement. Correct results rank by score, then server-recorded elapsed time.

27

Frequency Rank

Rank token frequencies under count and lexical tie-breaks. Correct results rank by score, then server-recorded elapsed time.

28

Window Scan

Find the earliest maximum-sum fixed-width contiguous window. Correct results rank by score, then server-recorded elapsed time.

29

Version Resolver

Select the highest semantic version satisfying every supplied constraint. Correct results rank by score, then server-recorded elapsed time.

30

Access Control

Resolve access requests under priority, wildcard, and deny precedence. Correct results rank by score, then server-recorded elapsed time.

31

Expression Stack

Evaluate a complete reverse-Polish stack expression. Correct results rank by score, then server-recorded elapsed time.

COURSE UNSEALED

Shared payload and solution

{
  "challenge": {
    "kind": "bracket-audit",
    "nonce": "JWXhfOmyuJj5o8t6HXbA77eK",
    "indexing": "zero-based",
    "sequence": "(([]){})",
    "instruction": "Return valid, invalid:index for the first bad closing bracket, or unclosed:index for the earliest unmatched opener"
  },
  "solution": "valid"
}