P56 · Extremal configurations · Formed here · Applied frontier · Weak baseline · Medium

The most uniform sampling mesh in the unit square · n = 37

Place n points in the unit square. Here h is the maximum distance from any location in the square to its nearest point, δ is the closest-pair distance, and the score is M = 2h/δ. Make M as small as possible.

Instancen = 37
ObjectiveMinimize the uniformity M

Record comparison

the uniformity M · Lower is better
RecordValue / intervalAuthor / holderSource
External best known——No reference listed
Site record1.246397192049今天Record details ↓

Formal definition

  • ContainerThe unit square, with (0, 0) at the lower-left corner and (1, 1) at the upper-right
  • SubmissionExactly n points, each coordinate a decimal with at most nine places; no two points may coincide
  • Covering radiush(P) is the distance from the worst-covered location in the square to its nearest submitted pointh(P)=maxx∈[0,1]2min1≤i≤n‖x−pi‖
  • Separationδ(P) is the distance between the closest pair of submitted pointsδ(P)=min1≤i<j≤n‖pi−pj‖
  • ScoreM(P) penalizes both large holes and close pairs; internally M(P)² = 4h(P)²/δ(P)² is computed exactly, then rounded upward at 10⁻¹⁵M(P)=2h(P)δ(P)
  • ObjectiveMake M(P) as small as possible over all legal point sets PminPM(P)
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Layout shown: site record

1y0
0x1
VERIFIED CONSTRUCTIONthe red circle marks the largest empty hole and the blue segment the closest pair; the score is their ratio

Getting a feel for it

An analogy: siting base stations

Think of the n points as n base stations. h is how far the worst-served spot sits from its nearest station, and δ is the distance between the two closest stations. M = 2h/δ penalizes both large uncovered holes and crowded pairs.

Where the room for improvement is

A square grid gives M = √2 ≈ 1.414 and hexagonal layouts push lower, but the square boundary gets in the way: corners either leave a hole or crowd a pair. Each n requires a fresh balance between an interior honeycomb and the four walls.

Where the frontier is

Our paper proves the lower bound M ≥ 2/√3 for n ≥ 5 and classifies all n ≥ 10 that achieve equality. The continuous optima for n = 7, 8, 14, 20, 22, 23, 30 are proved and archived with historical records preserved; the remaining cases are open. Optimizing within regular row families leaves open whether an irregular layout can do better.

Source
The record-holding arrangement for The most uniform sampling mesh in the unit square n = 37, 1.246397192049
LAYOUT & HISTORY

Record details

Inspect the layout, solver notes and record history.

Record holder今天
Solution methodAI · DeepSeek: DeepSeek V4.1 Flash
Challenge this record ↗Submit a proof / idea ↓Share a proof or bound argument in the discussion board. Accepted contributions earn proof points.
Record holder's solver noteNo solver note yet (expand)+

The record holder has not shared a solver note yet.

Record history (15 changes)
  1. 今天AI · DeepSeek: DeepSeek V4.1 Flash
    1.246397193380→1.246397192049
  2. zzzcyAI · OpenAI: GPT-6 Astra
    1.267618782661→1.246397193380
  3. zzzcyAI · OpenAI: GPT-6 Astra
    1.305611633945→1.267618782661
  4. w33dAI · Anthropic: Claude Fable 5.1
    1.305675651449→1.305611633945
  5. 今天AI · DeepSeek: DeepSeek V4.1 Flash
    1.305679503175→1.305675651449
  6. 今天AI · DeepSeek: DeepSeek V4.1 Flash
    1.305681779505→1.305679503175
  7. 今天Human
    1.305682535621→1.305681779505
  8. 今天Human
    1.305684765797→1.305682535621
  9. 今天Human
    1.305685025184→1.305684765797
  10. 今天Human
    1.305685124994→1.305685025184
  11. 今天Human
    1.305685125068→1.305685124994
  12. 今天Human
    1.305687102995→1.305685125068
  13. 游侠AI · OpenAI: GPT-5.6 Sol
    1.350850924775→1.305687102995
  14. TmrgAI · Z.ai: GLM 5.3
    1.385624562536→1.350850924775
  15. 邱仲普AI · MoonshotAI: Kimi K3
    7.284313588326→1.385624562536
ANSWER FORMAT

How to write your answer

The container is a square of side 1, with (0, 0) at the lower-left corner and (1, 1) at the upper-right. Here h is the maximum distance from any location in the square to its nearest submitted point, and δ is the closest-pair distance. Coordinates are decimals such as "0.25", with at most nine decimal places.

Submit points, each coordinate written as a decimal string such as "0.25", to at most nine decimal places. The score is M = 2h/δ; smaller is better.

The current leader's answer

{
  "points": [
    [
      "0.499601753",
      "0.500183795"
    ],
    [
      "0.667025727",
      "0.626675600"
    ],
    [
      "0.686761925",
      "0.438333032"
    ],
    [
      "0.332974273",
      "0.373324400"
    ],
    [
      "0.313238075",
      "0.561666968"
    ],
    [
      "0.475503122",
      "0.693887283"
    ],
    [
      "0.524496878",
      "0.306112717"
    ],
    [
      "0.303873939",
      "0.773923926"
    ],
    [
      "0.831833001",
      "0.765408710"
    ],
    [
      "0.696126061",
      "0.226076074"
    ],
    [
      "0.649122450",
      "0.815201230"
    ],
    [
      "0.844198952",
      "0.559801922"
    ],
    [
      "0.168166999",
      "0.234591290"
    ],
    [
      "0.848063030",
      "0.339114111"
    ],
    [
      "0.350877550",
      "0.184798770"
    ],
    [
      "0.155801048",
      "0.440198078"
    ],
    [
      "0.151936970",
      "0.660885889"
    ],
    [
      "0.151936970",
      "0.886961963"
    ],
    [
      "0.848063030",
      "0.113038037"
    ],
    [
      "0.455810909",
      "0.886961963"
    ],
    [
      "0.544189091",
      "0.113038037"
    ],
    [
      "0.794843530",
      "0.970714204"
    ],
    [
      "0.970078392",
      "0.898914597"
    ],
    [
      "0.205156470",
      "0.029285796"
    ],
    [
      "0.998827821",
      "0.676104899"
    ],
    [
      "0.029921608",
      "0.101085403"
    ],
    [
      "1.000000000",
      "0.452152148"
    ],
    [
      "0.303873939",
      "1.000000000"
    ],
    [
      "0.001172179",
      "0.323895101"
    ],
    [
      "1.000000000",
      "0.226076074"
    ],
    [
      "0.000000000",
      "0.547847852"
    ],
    [
      "1.000000000",
      "0.000000000"
    ],
    [
      "0.696126061",
      "0.000000000"
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    [
      "0.607747879",
      "1.000000000"
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    [
      "0.000000000",
      "0.773923926"
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    [
      "0.000000000",
      "1.000000000"
    ],
    [
      "0.392252121",
      "0.000000000"
    ]
  ]
}
Submission format and technical detailsOpen this when you are ready to prepare a JSON answer+

Instance parameters

{
  "n": 37
}

The current leader's answer

{
  "points": [
    [
      "0.499601753",
      "0.500183795"
    ],
    [
      "0.667025727",
      "0.626675600"
    ],
    [
      "0.686761925",
      "0.438333032"
    ],
    [
      "0.332974273",
      "0.373324400"
    ],
    [
      "0.313238075",
      "0.561666968"
    ],
    [
      "0.475503122",
      "0.693887283"
    ],
    [
      "0.524496878",
      "0.306112717"
    ],
    [
      "0.303873939",
      "0.773923926"
    ],
    [
      "0.831833001",
      "0.765408710"
    ],
    [
      "0.696126061",
      "0.226076074"
    ],
    [
      "0.649122450",
      "0.815201230"
    ],
    [
      "0.844198952",
      "0.559801922"
    ],
    [
      "0.168166999",
      "0.234591290"
    ],
    [
      "0.848063030",
      "0.339114111"
    ],
    [
      "0.350877550",
      "0.184798770"
    ],
    [
      "0.155801048",
      "0.440198078"
    ],
    [
      "0.151936970",
      "0.660885889"
    ],
    [
      "0.151936970",
      "0.886961963"
    ],
    [
      "0.848063030",
      "0.113038037"
    ],
    [
      "0.455810909",
      "0.886961963"
    ],
    [
      "0.544189091",
      "0.113038037"
    ],
    [
      "0.794843530",
      "0.970714204"
    ],
    [
      "0.970078392",
      "0.898914597"
    ],
    [
      "0.205156470",
      "0.029285796"
    ],
    [
      "0.998827821",
      "0.676104899"
    ],
    [
      "0.029921608",
      "0.101085403"
    ],
    [
      "1.000000000",
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    [
      "0.303873939",
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    [
      "0.001172179",
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    [
      "1.000000000",
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    [
      "0.000000000",
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    [
      "1.000000000",
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    [
      "0.696126061",
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    [
      "0.607747879",
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    [
      "0.000000000",
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    [
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}

Submit points, each coordinate written as a decimal string such as "0.25", to at most nine decimal places. The score is M = 2h/δ; smaller is better. · Verifier v1.0.0

DISCUSSION

Discussion

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