P82 · Packing and covering · Classic · Hard

Equal circles in regular polygons · m = 6 · n = 28

Pack n equal circles into the regular m-gon with centre (1,1), circumradius 1, and first vertex (2,1) so as to maximise their common radius.

Instancem = 6 · n = 28
ObjectiveMaximize circle radius

Record comparison

circle radius · Higher is better
RecordValue / intervalAuthor / holderSource
External best known[0.151660010857, 0.151660010859]Eckard SpechtPackomania ↗
Site recordNo player record yet——

Formal definition

  • ContainerThe editor and certificate normalise the container to the exact regular m-gon with centre (1,1), circumradius 1, and first vertex (2,1), while public scores follow the literature convention. Boundary contact is allowed.
  • SubmissionSubmit {radius, placements:[{x,y,turn},…]}, with each value written as a decimal string of at most nine places. Here x, y are centre coordinates; circles require turn = 0 and polygons use turn = tan(θ/2). Coordinates and turn must lie in [−4, 4], with 0 < radius ≤ 4.
  • ConstraintsExactly n congruent pieces lie wholly inside the container with pairwise disjoint interiors. Polygons may rotate independently by arbitrary angles.
  • PrecisionInput decimals are parsed as exact rationals and regular-polygon vertices are defined algebraically, with zero floating-point tolerance in feasibility checks.
  • ObjectiveMaximise the circle radius r (with container circumradius fixed at 1).
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Layout shown: starter layout

VERIFIED CONSTRUCTIONVERIFIED CONSTRUCTION

Getting a feel for it

Literature targets and coordinate certificates

Literature targets are converted at their published precision, while nine-decimal coordinate certificates are stored and displayed alongside the source values. Pentagon and hexagon rows n = 41–100 and octagon rows n = 41–48 cite Packomania's value and author without importing its coordinates; they start from an ordinary site grid baseline.

Source
The current arrangement for Equal circles in regular polygons m = 6 · n = 28
LAYOUT & HISTORY

Starter layout

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ANSWER FORMAT

How to write your answer

the regular m-gon with centre (1,1), circumradius 1, and first vertex (2,1)

Submit {radius, placements:[{x,y,turn},…]}, with each value written as a decimal string of at most nine places. Here x, y are centre coordinates; circles require turn = 0 and polygons use turn = tan(θ/2). Coordinates and turn must lie in [−4, 4], with 0 < radius ≤ 4.

Starter answer

{
  "placements": [
    {
      "turn": "0",
      "x": "0.715680505",
      "y": "0.285634607"
    },
    {
      "turn": "0",
      "x": "1.019000527",
      "y": "0.285634607"
    },
    {
      "turn": "0",
      "x": "1.322320549",
      "y": "0.285634607"
    },
    {
      "turn": "0",
      "x": "0.478441918",
      "y": "0.474634311"
    },
    {
      "turn": "0",
      "x": "1.536463194",
      "y": "0.500450722"
    },
    {
      "turn": "0",
      "x": "0.867340516",
      "y": "0.548317451"
    },
    {
      "turn": "0",
      "x": "1.170660538",
      "y": "0.548317451"
    },
    {
      "turn": "0",
      "x": "0.326781907",
      "y": "0.737317156"
    },
    {
      "turn": "0",
      "x": "0.630101929",
      "y": "0.737317156"
    },
    {
      "turn": "0",
      "x": "1.384803183",
      "y": "0.763133566"
    },
    {
      "turn": "0",
      "x": "1.688123204",
      "y": "0.763133566"
    },
    {
      "turn": "0",
      "x": "1.019000527",
      "y": "0.811000296"
    },
    {
      "turn": "0",
      "x": "0.175121896",
      "y": "1.000000000"
    },
    {
      "turn": "0",
      "x": "0.478441918",
      "y": "1.000000000"
    },
    {
      "turn": "0",
      "x": "0.781761940",
      "y": "1.000000000"
    },
    {
      "turn": "0",
      "x": "1.495202581",
      "y": "1.045649068"
    },
    {
      "turn": "0",
      "x": "1.798522602",
      "y": "1.045649068"
    },
    {
      "turn": "0",
      "x": "1.192221911",
      "y": "1.059993042"
    },
    {
      "turn": "0",
      "x": "0.954983324",
      "y": "1.248992746"
    },
    {
      "turn": "0",
      "x": "0.326781907",
      "y": "1.262682844"
    },
    {
      "turn": "0",
      "x": "0.646602750",
      "y": "1.271620451"
    },
    {
      "turn": "0",
      "x": "1.646862592",
      "y": "1.308331912"
    },
    {
      "turn": "0",
      "x": "1.264210321",
      "y": "1.370833038"
    },
    {
      "turn": "0",
      "x": "0.478441918",
      "y": "1.525365689"
    },
    {
      "turn": "0",
      "x": "0.971787483",
      "y": "1.551846928"
    },
    {
      "turn": "0",
      "x": "1.495202581",
      "y": "1.571014756"
    },
    {
      "turn": "0",
      "x": "0.715680505",
      "y": "1.714365393"
    },
    {
      "turn": "0",
      "x": "1.227894462",
      "y": "1.714365393"
    }
  ],
  "radius": "0.151660010"
}
Submission format and technical detailsOpen this when you are ready to prepare a JSON answer+

Instance parameters

{
  "n": 28,
  "sides": 6
}

Starter answer

{
  "placements": [
    {
      "turn": "0",
      "x": "0.715680505",
      "y": "0.285634607"
    },
    {
      "turn": "0",
      "x": "1.019000527",
      "y": "0.285634607"
    },
    {
      "turn": "0",
      "x": "1.322320549",
      "y": "0.285634607"
    },
    {
      "turn": "0",
      "x": "0.478441918",
      "y": "0.474634311"
    },
    {
      "turn": "0",
      "x": "1.536463194",
      "y": "0.500450722"
    },
    {
      "turn": "0",
      "x": "0.867340516",
      "y": "0.548317451"
    },
    {
      "turn": "0",
      "x": "1.170660538",
      "y": "0.548317451"
    },
    {
      "turn": "0",
      "x": "0.326781907",
      "y": "0.737317156"
    },
    {
      "turn": "0",
      "x": "0.630101929",
      "y": "0.737317156"
    },
    {
      "turn": "0",
      "x": "1.384803183",
      "y": "0.763133566"
    },
    {
      "turn": "0",
      "x": "1.688123204",
      "y": "0.763133566"
    },
    {
      "turn": "0",
      "x": "1.019000527",
      "y": "0.811000296"
    },
    {
      "turn": "0",
      "x": "0.175121896",
      "y": "1.000000000"
    },
    {
      "turn": "0",
      "x": "0.478441918",
      "y": "1.000000000"
    },
    {
      "turn": "0",
      "x": "0.781761940",
      "y": "1.000000000"
    },
    {
      "turn": "0",
      "x": "1.495202581",
      "y": "1.045649068"
    },
    {
      "turn": "0",
      "x": "1.798522602",
      "y": "1.045649068"
    },
    {
      "turn": "0",
      "x": "1.192221911",
      "y": "1.059993042"
    },
    {
      "turn": "0",
      "x": "0.954983324",
      "y": "1.248992746"
    },
    {
      "turn": "0",
      "x": "0.326781907",
      "y": "1.262682844"
    },
    {
      "turn": "0",
      "x": "0.646602750",
      "y": "1.271620451"
    },
    {
      "turn": "0",
      "x": "1.646862592",
      "y": "1.308331912"
    },
    {
      "turn": "0",
      "x": "1.264210321",
      "y": "1.370833038"
    },
    {
      "turn": "0",
      "x": "0.478441918",
      "y": "1.525365689"
    },
    {
      "turn": "0",
      "x": "0.971787483",
      "y": "1.551846928"
    },
    {
      "turn": "0",
      "x": "1.495202581",
      "y": "1.571014756"
    },
    {
      "turn": "0",
      "x": "0.715680505",
      "y": "1.714365393"
    },
    {
      "turn": "0",
      "x": "1.227894462",
      "y": "1.714365393"
    }
  ],
  "radius": "0.151660010"
}

Submit {radius, placements:[{x,y,turn},…]}, with each value written as a decimal string of at most nine places. Here x, y are centre coordinates; circles require turn = 0 and polygons use turn = tan(θ/2). Coordinates and turn must lie in [−4, 4], with 0 < radius ≤ 4. · Verifier v1.0.0

DISCUSSION

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