P82 · Packing and covering · Classic · Hard

Equal circles in regular polygons · m = 5 · n = 37

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 = 5 · n = 37
ObjectiveMaximize circle radius

Record comparison

circle radius · Higher is better
RecordValue / intervalAuthor / holderSource
External best known[0.126679668745, 0.126679668747]Paolo AmorePackomania ↗
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 = 5 · n = 37
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": "0.317662674",
      "y": "1.348995033"
    },
    {
      "turn": "0",
      "x": "0.317662674",
      "y": "1.013445114"
    },
    {
      "turn": "0",
      "x": "0.317662674",
      "y": "0.760085777"
    },
    {
      "turn": "0",
      "x": "0.317662674",
      "y": "0.506726439"
    },
    {
      "turn": "0",
      "x": "0.475634694",
      "y": "1.547075306"
    },
    {
      "turn": "0",
      "x": "0.507511343",
      "y": "1.181220074"
    },
    {
      "turn": "0",
      "x": "0.557884385",
      "y": "0.932918824"
    },
    {
      "turn": "0",
      "x": "0.557884385",
      "y": "0.679559487"
    },
    {
      "turn": "0",
      "x": "0.557884385",
      "y": "0.426200149"
    },
    {
      "turn": "0",
      "x": "0.668882313",
      "y": "1.376541255"
    },
    {
      "turn": "0",
      "x": "0.716593743",
      "y": "1.625367647"
    },
    {
      "turn": "0",
      "x": "0.762639805",
      "y": "1.130557316"
    },
    {
      "turn": "0",
      "x": "0.777300008",
      "y": "0.806239155"
    },
    {
      "turn": "0",
      "x": "0.777300008",
      "y": "0.552879818"
    },
    {
      "turn": "0",
      "x": "0.880350534",
      "y": "0.321424546"
    },
    {
      "turn": "0",
      "x": "0.909841361",
      "y": "1.454833596"
    },
    {
      "turn": "0",
      "x": "0.957552792",
      "y": "1.703659988"
    },
    {
      "turn": "0",
      "x": "0.969063689",
      "y": "0.971821897"
    },
    {
      "turn": "0",
      "x": "0.996715631",
      "y": "0.679559487"
    },
    {
      "turn": "0",
      "x": "1.009560771",
      "y": "1.221923757"
    },
    {
      "turn": "0",
      "x": "1.099766157",
      "y": "0.448104215"
    },
    {
      "turn": "0",
      "x": "1.151021478",
      "y": "1.540072637"
    },
    {
      "turn": "0",
      "x": "1.188479312",
      "y": "0.845142229"
    },
    {
      "turn": "0",
      "x": "1.202816683",
      "y": "0.216648943"
    },
    {
      "turn": "0",
      "x": "1.211386700",
      "y": "1.786135624"
    },
    {
      "turn": "0",
      "x": "1.228976394",
      "y": "1.095244088"
    },
    {
      "turn": "0",
      "x": "1.291529838",
      "y": "0.613686957"
    },
    {
      "turn": "0",
      "x": "1.303181009",
      "y": "1.337493193"
    },
    {
      "turn": "0",
      "x": "1.394580365",
      "y": "0.382231685"
    },
    {
      "turn": "0",
      "x": "1.397306092",
      "y": "1.614016673"
    },
    {
      "turn": "0",
      "x": "1.440450720",
      "y": "0.818658966"
    },
    {
      "turn": "0",
      "x": "1.480947802",
      "y": "1.068760826"
    },
    {
      "turn": "0",
      "x": "1.543501247",
      "y": "0.587203694"
    },
    {
      "turn": "0",
      "x": "1.546226974",
      "y": "1.409044663"
    },
    {
      "turn": "0",
      "x": "1.692422129",
      "y": "0.792175704"
    },
    {
      "turn": "0",
      "x": "1.695147856",
      "y": "1.204072654"
    },
    {
      "turn": "0",
      "x": "1.841343011",
      "y": "0.997147714"
    }
  ],
  "radius": "0.126679668"
}
Submission format and technical detailsOpen this when you are ready to prepare a JSON answer+

Instance parameters

{
  "n": 37,
  "sides": 5
}

Starter answer

{
  "placements": [
    {
      "turn": "0",
      "x": "0.317662674",
      "y": "1.348995033"
    },
    {
      "turn": "0",
      "x": "0.317662674",
      "y": "1.013445114"
    },
    {
      "turn": "0",
      "x": "0.317662674",
      "y": "0.760085777"
    },
    {
      "turn": "0",
      "x": "0.317662674",
      "y": "0.506726439"
    },
    {
      "turn": "0",
      "x": "0.475634694",
      "y": "1.547075306"
    },
    {
      "turn": "0",
      "x": "0.507511343",
      "y": "1.181220074"
    },
    {
      "turn": "0",
      "x": "0.557884385",
      "y": "0.932918824"
    },
    {
      "turn": "0",
      "x": "0.557884385",
      "y": "0.679559487"
    },
    {
      "turn": "0",
      "x": "0.557884385",
      "y": "0.426200149"
    },
    {
      "turn": "0",
      "x": "0.668882313",
      "y": "1.376541255"
    },
    {
      "turn": "0",
      "x": "0.716593743",
      "y": "1.625367647"
    },
    {
      "turn": "0",
      "x": "0.762639805",
      "y": "1.130557316"
    },
    {
      "turn": "0",
      "x": "0.777300008",
      "y": "0.806239155"
    },
    {
      "turn": "0",
      "x": "0.777300008",
      "y": "0.552879818"
    },
    {
      "turn": "0",
      "x": "0.880350534",
      "y": "0.321424546"
    },
    {
      "turn": "0",
      "x": "0.909841361",
      "y": "1.454833596"
    },
    {
      "turn": "0",
      "x": "0.957552792",
      "y": "1.703659988"
    },
    {
      "turn": "0",
      "x": "0.969063689",
      "y": "0.971821897"
    },
    {
      "turn": "0",
      "x": "0.996715631",
      "y": "0.679559487"
    },
    {
      "turn": "0",
      "x": "1.009560771",
      "y": "1.221923757"
    },
    {
      "turn": "0",
      "x": "1.099766157",
      "y": "0.448104215"
    },
    {
      "turn": "0",
      "x": "1.151021478",
      "y": "1.540072637"
    },
    {
      "turn": "0",
      "x": "1.188479312",
      "y": "0.845142229"
    },
    {
      "turn": "0",
      "x": "1.202816683",
      "y": "0.216648943"
    },
    {
      "turn": "0",
      "x": "1.211386700",
      "y": "1.786135624"
    },
    {
      "turn": "0",
      "x": "1.228976394",
      "y": "1.095244088"
    },
    {
      "turn": "0",
      "x": "1.291529838",
      "y": "0.613686957"
    },
    {
      "turn": "0",
      "x": "1.303181009",
      "y": "1.337493193"
    },
    {
      "turn": "0",
      "x": "1.394580365",
      "y": "0.382231685"
    },
    {
      "turn": "0",
      "x": "1.397306092",
      "y": "1.614016673"
    },
    {
      "turn": "0",
      "x": "1.440450720",
      "y": "0.818658966"
    },
    {
      "turn": "0",
      "x": "1.480947802",
      "y": "1.068760826"
    },
    {
      "turn": "0",
      "x": "1.543501247",
      "y": "0.587203694"
    },
    {
      "turn": "0",
      "x": "1.546226974",
      "y": "1.409044663"
    },
    {
      "turn": "0",
      "x": "1.692422129",
      "y": "0.792175704"
    },
    {
      "turn": "0",
      "x": "1.695147856",
      "y": "1.204072654"
    },
    {
      "turn": "0",
      "x": "1.841343011",
      "y": "0.997147714"
    }
  ],
  "radius": "0.126679668"
}

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

Discussion

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