P05 · 装箱与覆盖 · 经典问题 · 难

可倾斜等正方形装入圆 · n = 27

文献中也称squares in circlespacking unit squares in a circle

在半径 1 的圆内放 n 个可任意旋转的正方形,边长完全相同、互不重叠,使共同边长尽可能大。

子题n = 27
目标最大化 最小边长

严格定义

  • 容器半径 1 的圆,圆心在 (1, 1),两个坐标都在 0 到 2 之间
  • 提交每个正方形写 {cx, cy, ux, uy}:中心加一条半边向量,另一条固定取 (−uy, ux)
  • 约束每个正方形的角度完全自由;全部落在容器内;两两内部不重叠,贴边接触允许。计分只看最小的那个正方形,所以边长不一致占不到便宜
  • 目标让共同边长尽可能大。内部以其平方精确比较
放大来摆,然后提交
2y0
0x2
已验证构造27 个正方形

帮助理解

哪里有优化空间

圆形容器没有角:正方形的直边贴不住弧形边界,最优解几乎总是倾斜的,正方形彼此以角相抵。

前沿在哪里

n = 4 已证明;n ≤ 35 的其余已知最好值取自 Friedman 的 squares-in-circles 汇总(1997 年起多人贡献),全部未证明;n = 36–40 没有任何公开记录,从零开始。

查看来源
可倾斜等正方形装入圆 n = 27 的当前纪录构型,0.306672835
当前第一名

0.306672835

最小边长

答案来源Milan Kovacic
解题方式公开参考构造
挑战这个纪录 提交证明 / 思路 在讨论区分享证明或思路,审核采纳后可获得证明分。
纪录保持者的求解笔记暂无求解笔记(点击展开)

纪录保持者还没有分享求解过程。

ANSWER FORMAT

答案怎么写

容器是半径 1 的圆,圆心在 (1, 1),所以坐标范围是 0 到 2。坐标和向量用同一个单位,直接写成小数,例如 "0.4",最多九位小数。

每个正方形提交 {cx,cy,ux,uy}:中心加一条半边向量,另一条半边向量固定取 (-uy,ux)。每个数写成十进制字符串,例如 "0.4";角度完全自由,计分取最小正方形的边长,所以把它们写得一样大最划算。边长本身几乎总是无理数,写不成有限小数,所以你写的是那条半边向量,边长由它精确定出。

当前第一名的答案

{
  "squares": [
    {
      "cx": "0.263844100",
      "cy": "1.305424515",
      "ux": "0.153324672",
      "uy": "-0.001897870"
    },
    {
      "cx": "1.798024971",
      "cy": "1.156127990",
      "ux": "0.153334971",
      "uy": "0.000666079"
    },
    {
      "cx": "1.798920939",
      "cy": "0.849455235",
      "ux": "0.153334971",
      "uy": "0.000666080"
    },
    {
      "cx": "0.822679109",
      "cy": "1.779295159",
      "ux": "0.153027135",
      "uy": "0.009734115"
    },
    {
      "cx": "1.186305181",
      "cy": "1.496845730",
      "ux": "0.153324673",
      "uy": "-0.001897866"
    },
    {
      "cx": "1.127054333",
      "cy": "0.192978016",
      "ux": "0.153334972",
      "uy": "0.000665967"
    },
    {
      "cx": "1.139610486",
      "cy": "1.804122011",
      "ux": "0.153324661",
      "uy": "-0.001898781"
    },
    {
      "cx": "1.473475140",
      "cy": "0.322614812",
      "ux": "0.131309443",
      "uy": "0.079182621"
    },
    {
      "cx": "0.512843729",
      "cy": "0.385481406",
      "ux": "0.153334984",
      "uy": "0.000663224"
    },
    {
      "cx": "0.572896389",
      "cy": "0.692446970",
      "ux": "0.153334971",
      "uy": "0.000666070"
    },
    {
      "cx": "1.492953012",
      "cy": "0.686304005",
      "ux": "0.153334971",
      "uy": "0.000666081"
    },
    {
      "cx": "0.820299283",
      "cy": "0.210851894",
      "ux": "0.153334975",
      "uy": "0.000665196"
    },
    {
      "cx": "1.186762824",
      "cy": "0.574316354",
      "ux": "0.153334971",
      "uy": "0.000666072"
    },
    {
      "cx": "0.514922437",
      "cy": "1.616109910",
      "ux": "0.153329064",
      "uy": "-0.001501792"
    },
    {
      "cx": "0.878999572",
      "cy": "0.824461061",
      "ux": "0.153334971",
      "uy": "0.000666070"
    },
    {
      "cx": "0.880331725",
      "cy": "0.517790203",
      "ux": "0.153334971",
      "uy": "0.000666072"
    },
    {
      "cx": "1.494388157",
      "cy": "1.608839335",
      "ux": "0.153324673",
      "uy": "-0.001897802"
    },
    {
      "cx": "1.490593041",
      "cy": "1.302189524",
      "ux": "0.153324673",
      "uy": "-0.001897868"
    },
    {
      "cx": "1.185430666",
      "cy": "0.880987333",
      "ux": "0.153334971",
      "uy": "0.000666070"
    },
    {
      "cx": "0.266225310",
      "cy": "0.691165734",
      "ux": "0.153334971",
      "uy": "0.000666072"
    },
    {
      "cx": "0.879144922",
      "cy": "1.459432661",
      "ux": "0.153324673",
      "uy": "-0.001897867"
    },
    {
      "cx": "1.182509506",
      "cy": "1.190193759",
      "ux": "0.153324673",
      "uy": "-0.001897868"
    },
    {
      "cx": "1.491620850",
      "cy": "0.992974864",
      "ux": "0.153334971",
      "uy": "0.000666079"
    },
    {
      "cx": "0.165326655",
      "cy": "0.997404086",
      "ux": "0.153334971",
      "uy": "0.000666072"
    },
    {
      "cx": "0.570577101",
      "cy": "1.308312914",
      "ux": "0.153324673",
      "uy": "-0.001897867"
    },
    {
      "cx": "0.566781304",
      "cy": "1.001658761",
      "ux": "0.153324672",
      "uy": "-0.001897870"
    },
    {
      "cx": "0.875113581",
      "cy": "1.133749049",
      "ux": "0.153324673",
      "uy": "-0.001897867"
    }
  ]
}
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": 27
}

当前第一名的答案

{
  "squares": [
    {
      "cx": "0.263844100",
      "cy": "1.305424515",
      "ux": "0.153324672",
      "uy": "-0.001897870"
    },
    {
      "cx": "1.798024971",
      "cy": "1.156127990",
      "ux": "0.153334971",
      "uy": "0.000666079"
    },
    {
      "cx": "1.798920939",
      "cy": "0.849455235",
      "ux": "0.153334971",
      "uy": "0.000666080"
    },
    {
      "cx": "0.822679109",
      "cy": "1.779295159",
      "ux": "0.153027135",
      "uy": "0.009734115"
    },
    {
      "cx": "1.186305181",
      "cy": "1.496845730",
      "ux": "0.153324673",
      "uy": "-0.001897866"
    },
    {
      "cx": "1.127054333",
      "cy": "0.192978016",
      "ux": "0.153334972",
      "uy": "0.000665967"
    },
    {
      "cx": "1.139610486",
      "cy": "1.804122011",
      "ux": "0.153324661",
      "uy": "-0.001898781"
    },
    {
      "cx": "1.473475140",
      "cy": "0.322614812",
      "ux": "0.131309443",
      "uy": "0.079182621"
    },
    {
      "cx": "0.512843729",
      "cy": "0.385481406",
      "ux": "0.153334984",
      "uy": "0.000663224"
    },
    {
      "cx": "0.572896389",
      "cy": "0.692446970",
      "ux": "0.153334971",
      "uy": "0.000666070"
    },
    {
      "cx": "1.492953012",
      "cy": "0.686304005",
      "ux": "0.153334971",
      "uy": "0.000666081"
    },
    {
      "cx": "0.820299283",
      "cy": "0.210851894",
      "ux": "0.153334975",
      "uy": "0.000665196"
    },
    {
      "cx": "1.186762824",
      "cy": "0.574316354",
      "ux": "0.153334971",
      "uy": "0.000666072"
    },
    {
      "cx": "0.514922437",
      "cy": "1.616109910",
      "ux": "0.153329064",
      "uy": "-0.001501792"
    },
    {
      "cx": "0.878999572",
      "cy": "0.824461061",
      "ux": "0.153334971",
      "uy": "0.000666070"
    },
    {
      "cx": "0.880331725",
      "cy": "0.517790203",
      "ux": "0.153334971",
      "uy": "0.000666072"
    },
    {
      "cx": "1.494388157",
      "cy": "1.608839335",
      "ux": "0.153324673",
      "uy": "-0.001897802"
    },
    {
      "cx": "1.490593041",
      "cy": "1.302189524",
      "ux": "0.153324673",
      "uy": "-0.001897868"
    },
    {
      "cx": "1.185430666",
      "cy": "0.880987333",
      "ux": "0.153334971",
      "uy": "0.000666070"
    },
    {
      "cx": "0.266225310",
      "cy": "0.691165734",
      "ux": "0.153334971",
      "uy": "0.000666072"
    },
    {
      "cx": "0.879144922",
      "cy": "1.459432661",
      "ux": "0.153324673",
      "uy": "-0.001897867"
    },
    {
      "cx": "1.182509506",
      "cy": "1.190193759",
      "ux": "0.153324673",
      "uy": "-0.001897868"
    },
    {
      "cx": "1.491620850",
      "cy": "0.992974864",
      "ux": "0.153334971",
      "uy": "0.000666079"
    },
    {
      "cx": "0.165326655",
      "cy": "0.997404086",
      "ux": "0.153334971",
      "uy": "0.000666072"
    },
    {
      "cx": "0.570577101",
      "cy": "1.308312914",
      "ux": "0.153324673",
      "uy": "-0.001897867"
    },
    {
      "cx": "0.566781304",
      "cy": "1.001658761",
      "ux": "0.153324672",
      "uy": "-0.001897870"
    },
    {
      "cx": "0.875113581",
      "cy": "1.133749049",
      "ux": "0.153324673",
      "uy": "-0.001897867"
    }
  ]
}

每个正方形提交 {cx,cy,ux,uy}:中心加一条半边向量,另一条半边向量固定取 (-uy,ux)。每个数写成十进制字符串,例如 "0.4";角度完全自由,计分取最小正方形的边长,所以把它们写得一样大最划算。边长本身几乎总是无理数,写不成有限小数,所以你写的是那条半边向量,边长由它精确定出。 · 验证器 v1.0.0

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