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P12 · 装箱与覆盖 · 经典问题 · 难

2:1 长方形内的等圆装箱 · n = 78

文献中也称circles in a rectanglepacking equal circles in a 2:1 rectangle

在 2 × 1 的长方形内放置 n 个互不重叠的等圆，使它们的共同半径尽可能大。

子题n = 78
目标最大化 共同半径

纪录对比

共同半径 · 越大越好
纪录数值 / 区间作者 / 持有人来源
外部已知最好[0.081844778592465296751513720293, 0.081844778592465296751513720295]Eckard Specht1999–2010Packomania ↗
本站纪录0.081844778NUE_13纪录详情 ↓

本站纪录尚未确认达到或超越此参考纪录。

严格定义

  • 容器宽 2、高 1 的长方形 [0, 2] × [0, 1]，左下角为原点 (0, 0)，右上角为 (2, 1)
  • 提交恰好 n 个圆：一个共同半径 radius 与 n 个圆心坐标 centers
  • 约束每个圆完全位于长方形内；任意两圆内部不重叠，允许相切
  • 目标最大化共同半径 radius
挑战这个纪录 ↗

当前展示：本站纪录

1y0
0x2
已验证构造r = 0.081844778

帮助理解

交错之字层与行转换

在长宽比为 2 : 1 的狭长容器内，小规模时各圆通常交替贴靠上下长边排成之字形链；随着 n 增大，排布会在双层交错、三层蜂窝与局部斜排之间切换。除了完美契合 2 : 1 比例的偶数网格（如 2 × 1 或 4 × 2）外，整齐的轴对齐网格通常会浪费横向或纵向空间。

已知证明与开放前沿

n = 3..6 的最优半径可通过之字形链的初等几何下界严格证明（详见各子题的已知最优说明）；更大的 n 引用 Packomania 的 1 × 0.5 长方形表（本题是它放大两倍，半径也乘 2），表中只列出最优已知值，没有一项标为已证明最优。

2:1 长方形内的等圆装箱 n = 78 的当前纪录构型，0.081844778
构型与历史

纪录详情

查看构型、求解笔记与纪录历史。

纪录保持者NUE_13
解题方式AI · DeepSeek: DeepSeek V4.1 Flash
挑战这个纪录 ↗提交证明 / 思路 ↓在讨论区分享最优性证明或关键界限思路，经审核采纳后可获证明分。
纪录保持者的求解笔记暂无求解笔记（点击展开）＋

纪录保持者暂未分享求解过程。

历史纪录（2 次易主）
  1. NUE_13AI · DeepSeek: DeepSeek V4.1 Flash
    0.077407849→0.081844778
  2. NUE_13AI · DeepSeek: DeepSeek V4.1 Flash
    0.057142856→0.077407849
ANSWER FORMAT

答案怎么写

容器是宽 2、高 1 的长方形，左下角是原点 (0, 0)，右上角是 (2, 1)。坐标和长度用同一个单位，直接写成小数，例如 "0.25"，最多九位小数。

提交共同半径 radius 与各圆圆心坐标 centers，所有数值均以十进制字符串表示（如 "0.25"）。

当前第一名的答案

{
  "centers": [
    [
      "0.081844779",
      "0.081844779"
    ],
    [
      "0.245534336",
      "0.081844779"
    ],
    [
      "0.409223893",
      "0.081844779"
    ],
    [
      "0.614499166",
      "0.081844779"
    ],
    [
      "0.778188724",
      "0.081844779"
    ],
    [
      "0.941878281",
      "0.081844779"
    ],
    [
      "1.105567838",
      "0.081844779"
    ],
    [
      "1.269257395",
      "0.081844779"
    ],
    [
      "1.432946952",
      "0.081844779"
    ],
    [
      "1.638222226",
      "0.081844779"
    ],
    [
      "1.911873439",
      "0.082342582"
    ],
    [
      "1.772478954",
      "0.175489863"
    ],
    [
      "0.511861530",
      "0.209358647"
    ],
    [
      "1.535584589",
      "0.209358647"
    ],
    [
      "0.163689557",
      "0.223604093"
    ],
    [
      "0.327379114",
      "0.223604093"
    ],
    [
      "0.696343945",
      "0.223604093"
    ],
    [
      "0.860033502",
      "0.223604093"
    ],
    [
      "1.023723059",
      "0.223604093"
    ],
    [
      "1.187412616",
      "0.223604093"
    ],
    [
      "1.351102174",
      "0.223604093"
    ],
    [
      "1.918155221",
      "0.250140358"
    ],
    [
      "1.780667863",
      "0.338974459"
    ],
    [
      "0.430016751",
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    ],
    [
      "0.593706308",
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    ],
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      "1.453739810",
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    ],
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      "1.617429368",
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    ],
    [
      "0.081844779",
      "0.365363408"
    ],
    [
      "0.245534336",
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    ],
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    ],
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      "0.365363408"
    ],
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    ],
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      "0.634636592"
    ],
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      "0.757395865",
      "0.634636592"
    ],
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      "1.290050253",
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    ],
    [
      "1.453739810",
      "0.634636592"
    ],
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      "1.617429368",
      "0.634636592"
    ],
    [
      "0.081844779",
      "0.648882038"
    ],
    [
      "0.941878281",
      "0.648882038"
    ],
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      "1.105567838",
      "0.648882038"
    ],
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      "0.673441394"
    ],
    [
      "1.918155221",
      "0.755384670"
    ],
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      "0.184482415",
      "0.776395907"
    ],
    [
      "0.348171972",
      "0.776395907"
    ],
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      "0.511861530",
      "0.776395907"
    ],
    [
      "0.675551087",
      "0.776395907"
    ],
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      "0.839240644",
      "0.776395907"
    ],
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      "1.208205475",
      "0.776395907"
    ],
    [
      "1.371895032",
      "0.776395907"
    ],
    [
      "1.535584589",
      "0.776395907"
    ],
    [
      "1.023723059",
      "0.790641353"
    ],
    [
      "1.759131769",
      "0.836211945"
    ],
    [
      "0.082342582",
      "0.917657418"
    ],
    [
      "0.266327194",
      "0.918155221"
    ],
    [
      "0.430016751",
      "0.918155221"
    ],
    [
      "0.593706308",
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    ],
    [
      "0.757395865",
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    ],
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      "0.921085423",
      "0.918155221"
    ],
    [
      "1.126360696",
      "0.918155221"
    ],
    [
      "1.290050253",
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    ],
    [
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    ],
    [
      "1.617429368",
      "0.918155221"
    ],
    [
      "1.900834170",
      "0.918155221"
    ]
  ],
  "radius": "0.081844778"
}
提交格式与技术细节需要编写程序或准备 JSON 答案时再查看＋

子题参数

{
  "n": 78
}

当前第一名的答案

{
  "centers": [
    [
      "0.081844779",
      "0.081844779"
    ],
    [
      "0.245534336",
      "0.081844779"
    ],
    [
      "0.409223893",
      "0.081844779"
    ],
    [
      "0.614499166",
      "0.081844779"
    ],
    [
      "0.778188724",
      "0.081844779"
    ],
    [
      "0.941878281",
      "0.081844779"
    ],
    [
      "1.105567838",
      "0.081844779"
    ],
    [
      "1.269257395",
      "0.081844779"
    ],
    [
      "1.432946952",
      "0.081844779"
    ],
    [
      "1.638222226",
      "0.081844779"
    ],
    [
      "1.911873439",
      "0.082342582"
    ],
    [
      "1.772478954",
      "0.175489863"
    ],
    [
      "0.511861530",
      "0.209358647"
    ],
    [
      "1.535584589",
      "0.209358647"
    ],
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      "0.163689557",
      "0.223604093"
    ],
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    ],
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      "1.453739810",
      "0.918155221"
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      "1.617429368",
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    ],
    [
      "1.900834170",
      "0.918155221"
    ]
  ],
  "radius": "0.081844778"
}

提交共同半径 radius 与各圆圆心坐标 centers，所有数值均以十进制字符串表示（如 "0.25"）。 · 验证器 v1.0.0

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