P82 · Packing and covering · Classic · Hard

Equal circles in regular polygons · m = 5 · n = 29

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 = 29
ObjectiveMaximize circle radius

Record comparison

circle radius · Higher is better
RecordValue / intervalAuthor / holderSource
External best known[0.143333013134, 0.143333013136]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 = 5 · n = 29
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": "0.334316019",
      "y": "1.156224594"
    },
    {
      "turn": "0",
      "x": "0.334316019",
      "y": "0.856175342"
    },
    {
      "turn": "0",
      "x": "0.335930278",
      "y": "0.542560830"
    },
    {
      "turn": "0",
      "x": "0.337876693",
      "y": "1.455930203"
    },
    {
      "turn": "0",
      "x": "0.578590500",
      "y": "1.006199968"
    },
    {
      "turn": "0",
      "x": "0.578590500",
      "y": "0.706150716"
    },
    {
      "turn": "0",
      "x": "0.586378397",
      "y": "1.292760187"
    },
    {
      "turn": "0",
      "x": "0.622183113",
      "y": "1.577181412"
    },
    {
      "turn": "0",
      "x": "0.622183113",
      "y": "0.422818588"
    },
    {
      "turn": "0",
      "x": "0.822864982",
      "y": "0.856175342"
    },
    {
      "turn": "0",
      "x": "0.830652878",
      "y": "1.142735561"
    },
    {
      "turn": "0",
      "x": "0.866457595",
      "y": "1.427156786"
    },
    {
      "turn": "0",
      "x": "0.866457595",
      "y": "0.572843214"
    },
    {
      "turn": "0",
      "x": "0.975897539",
      "y": "1.692110195"
    },
    {
      "turn": "0",
      "x": "0.975897539",
      "y": "0.307889805"
    },
    {
      "turn": "0",
      "x": "1.109437056",
      "y": "0.848836601"
    },
    {
      "turn": "0",
      "x": "1.117224952",
      "y": "1.135396821"
    },
    {
      "turn": "0",
      "x": "1.151698587",
      "y": "1.455704763"
    },
    {
      "turn": "0",
      "x": "1.151698587",
      "y": "0.544295237"
    },
    {
      "turn": "0",
      "x": "1.248533131",
      "y": "1.780694869"
    },
    {
      "turn": "0",
      "x": "1.248533131",
      "y": "0.219305131"
    },
    {
      "turn": "0",
      "x": "1.370230971",
      "y": "1.270175769"
    },
    {
      "turn": "0",
      "x": "1.370230971",
      "y": "0.729824231"
    },
    {
      "turn": "0",
      "x": "1.421637601",
      "y": "1.552194862"
    },
    {
      "turn": "0",
      "x": "1.421637601",
      "y": "0.447805138"
    },
    {
      "turn": "0",
      "x": "1.481815360",
      "y": "1.000511469"
    },
    {
      "turn": "0",
      "x": "1.654332590",
      "y": "1.231917687"
    },
    {
      "turn": "0",
      "x": "1.654332590",
      "y": "0.768082313"
    },
    {
      "turn": "0",
      "x": "1.822830652",
      "y": "1.000000000"
    }
  ],
  "radius": "0.143333012"
}
Submission format and technical detailsOpen this when you are ready to prepare a JSON answer+

Instance parameters

{
  "n": 29,
  "sides": 5
}

Starter answer

{
  "placements": [
    {
      "turn": "0",
      "x": "0.334316019",
      "y": "1.156224594"
    },
    {
      "turn": "0",
      "x": "0.334316019",
      "y": "0.856175342"
    },
    {
      "turn": "0",
      "x": "0.335930278",
      "y": "0.542560830"
    },
    {
      "turn": "0",
      "x": "0.337876693",
      "y": "1.455930203"
    },
    {
      "turn": "0",
      "x": "0.578590500",
      "y": "1.006199968"
    },
    {
      "turn": "0",
      "x": "0.578590500",
      "y": "0.706150716"
    },
    {
      "turn": "0",
      "x": "0.586378397",
      "y": "1.292760187"
    },
    {
      "turn": "0",
      "x": "0.622183113",
      "y": "1.577181412"
    },
    {
      "turn": "0",
      "x": "0.622183113",
      "y": "0.422818588"
    },
    {
      "turn": "0",
      "x": "0.822864982",
      "y": "0.856175342"
    },
    {
      "turn": "0",
      "x": "0.830652878",
      "y": "1.142735561"
    },
    {
      "turn": "0",
      "x": "0.866457595",
      "y": "1.427156786"
    },
    {
      "turn": "0",
      "x": "0.866457595",
      "y": "0.572843214"
    },
    {
      "turn": "0",
      "x": "0.975897539",
      "y": "1.692110195"
    },
    {
      "turn": "0",
      "x": "0.975897539",
      "y": "0.307889805"
    },
    {
      "turn": "0",
      "x": "1.109437056",
      "y": "0.848836601"
    },
    {
      "turn": "0",
      "x": "1.117224952",
      "y": "1.135396821"
    },
    {
      "turn": "0",
      "x": "1.151698587",
      "y": "1.455704763"
    },
    {
      "turn": "0",
      "x": "1.151698587",
      "y": "0.544295237"
    },
    {
      "turn": "0",
      "x": "1.248533131",
      "y": "1.780694869"
    },
    {
      "turn": "0",
      "x": "1.248533131",
      "y": "0.219305131"
    },
    {
      "turn": "0",
      "x": "1.370230971",
      "y": "1.270175769"
    },
    {
      "turn": "0",
      "x": "1.370230971",
      "y": "0.729824231"
    },
    {
      "turn": "0",
      "x": "1.421637601",
      "y": "1.552194862"
    },
    {
      "turn": "0",
      "x": "1.421637601",
      "y": "0.447805138"
    },
    {
      "turn": "0",
      "x": "1.481815360",
      "y": "1.000511469"
    },
    {
      "turn": "0",
      "x": "1.654332590",
      "y": "1.231917687"
    },
    {
      "turn": "0",
      "x": "1.654332590",
      "y": "0.768082313"
    },
    {
      "turn": "0",
      "x": "1.822830652",
      "y": "1.000000000"
    }
  ],
  "radius": "0.143333012"
}

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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