LAPLINE
PASSPORTFIELD ACTIVE
DAILY CHALLENGE // 2026-09-04 // CLOSED

Coverage Draft

Find the smallest, lowest-cost deterministic set covering every target. 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

October 2026

31 COURSES
FINAL FIELD

0 results

NO RESULTS YET // THE FIELD IS OPEN

COURSE MANUAL // PUBLIC INTEL

Find the smallest deterministic sensor set covering every target.

ADVANCED // 15 MINUTES

Answer contract

An alphabetically sorted array of selected sensor ids.

Race plan

  1. Reject any subset that misses a target.
  2. Prefer fewer sensors before considering cost.
  3. Break remaining ties by total cost, then lexicographic id list.

Common mistakes

  • Minimizing cost before sensor count.
  • Assuming pairwise coverage implies total coverage.
  • Ignoring the final lexical tie-break.

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": "coverage-draft",
    "nonce": "VkqUwuK76TPgndmn-BksvIBL",
    "sensors": [
      {
        "id": "C",
        "cost": 4,
        "covers": [
          "T3",
          "T4"
        ]
      },
      {
        "id": "A",
        "cost": 4,
        "covers": [
          "T1",
          "T2"
        ]
      },
      {
        "id": "F",
        "cost": 5,
        "covers": [
          "T1",
          "T6"
        ]
      },
      {
        "id": "E",
        "cost": 4,
        "covers": [
          "T5",
          "T6"
        ]
      },
      {
        "id": "D",
        "cost": 3,
        "covers": [
          "T4",
          "T5"
        ]
      },
      {
        "id": "G",
        "cost": 2,
        "covers": [
          "T4",
          "T5",
          "T6"
        ]
      },
      {
        "id": "B",
        "cost": 3,
        "covers": [
          "T2",
          "T3"
        ]
      }
    ],
    "targets": [
      "T1",
      "T2",
      "T3",
      "T4",
      "T5",
      "T6"
    ],
    "instruction": "Cover every target; minimize sensor count, then total cost, then choose the lexicographically smaller sorted id list"
  },
  "solution": [
    "A",
    "B",
    "G"
  ]
}