P05 · 装箱与覆盖 · 经典问题 · 难

可倾斜等正方形装入圆 · n = 23

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 = 23
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23 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 = 23 的当前纪录构型,0.326009547
当前第一名

0.326009547

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": "1.333021036",
      "cy": "1.706006008",
      "ux": "0.162996773",
      "uy": "-0.001615027"
    },
    {
      "cx": "1.072427782",
      "cy": "0.844866531",
      "ux": "0.162996773",
      "uy": "-0.001615052"
    },
    {
      "cx": "0.681033881",
      "cy": "1.712466228",
      "ux": "0.162996773",
      "uy": "-0.001615049"
    },
    {
      "cx": "1.004930337",
      "cy": "1.497586477",
      "ux": "0.162996773",
      "uy": "-0.001615052"
    },
    {
      "cx": "1.023208928",
      "cy": "1.171379795",
      "ux": "0.162996773",
      "uy": "-0.001615050"
    },
    {
      "cx": "0.243584896",
      "cy": "0.771885730",
      "ux": "0.162996752",
      "uy": "-0.001617199"
    },
    {
      "cx": "1.814139140",
      "cy": "1.058380487",
      "ux": "0.162985507",
      "uy": "0.002506144"
    },
    {
      "cx": "0.696082374",
      "cy": "1.060265967",
      "ux": "0.162996773",
      "uy": "-0.001615047"
    },
    {
      "cx": "1.413250369",
      "cy": "1.051074187",
      "ux": "0.162985508",
      "uy": "0.002506137"
    },
    {
      "cx": "0.886860900",
      "cy": "0.521086230",
      "ux": "0.036119824",
      "uy": "0.158952555"
    },
    {
      "cx": "1.469458172",
      "cy": "0.376336247",
      "ux": "0.159272256",
      "uy": "0.034682919"
    },
    {
      "cx": "0.788947737",
      "cy": "0.209015059",
      "ux": "0.036119825",
      "uy": "0.158952555"
    },
    {
      "cx": "0.499106943",
      "cy": "0.404757479",
      "ux": "0.036119825",
      "uy": "0.158952555"
    },
    {
      "cx": "0.597020105",
      "cy": "0.716828655",
      "ux": "0.036119824",
      "uy": "0.158952555"
    },
    {
      "cx": "1.741521641",
      "cy": "0.723234384",
      "ux": "0.011546091",
      "uy": "0.162595339"
    },
    {
      "cx": "1.175244097",
      "cy": "0.195239101",
      "ux": "0.159272255",
      "uy": "0.034682923"
    },
    {
      "cx": "1.350177628",
      "cy": "1.376152462",
      "ux": "0.162985508",
      "uy": "0.002506137"
    },
    {
      "cx": "1.401333090",
      "cy": "0.724842833",
      "ux": "0.162985508",
      "uy": "0.002506137"
    },
    {
      "cx": "1.676131126",
      "cy": "1.382306527",
      "ux": "0.162985507",
      "uy": "0.002506144"
    },
    {
      "cx": "0.352136504",
      "cy": "1.422860031",
      "ux": "0.162996751",
      "uy": "-0.001617275"
    },
    {
      "cx": "1.008160427",
      "cy": "1.823580057",
      "ux": "0.162996773",
      "uy": "-0.001615048"
    },
    {
      "cx": "0.677803778",
      "cy": "1.386472653",
      "ux": "0.162996773",
      "uy": "-0.001615047"
    },
    {
      "cx": "0.223928928",
      "cy": "1.098106445",
      "ux": "0.162996751",
      "uy": "-0.001617270"
    }
  ]
}
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": 23
}

当前第一名的答案

{
  "squares": [
    {
      "cx": "1.333021036",
      "cy": "1.706006008",
      "ux": "0.162996773",
      "uy": "-0.001615027"
    },
    {
      "cx": "1.072427782",
      "cy": "0.844866531",
      "ux": "0.162996773",
      "uy": "-0.001615052"
    },
    {
      "cx": "0.681033881",
      "cy": "1.712466228",
      "ux": "0.162996773",
      "uy": "-0.001615049"
    },
    {
      "cx": "1.004930337",
      "cy": "1.497586477",
      "ux": "0.162996773",
      "uy": "-0.001615052"
    },
    {
      "cx": "1.023208928",
      "cy": "1.171379795",
      "ux": "0.162996773",
      "uy": "-0.001615050"
    },
    {
      "cx": "0.243584896",
      "cy": "0.771885730",
      "ux": "0.162996752",
      "uy": "-0.001617199"
    },
    {
      "cx": "1.814139140",
      "cy": "1.058380487",
      "ux": "0.162985507",
      "uy": "0.002506144"
    },
    {
      "cx": "0.696082374",
      "cy": "1.060265967",
      "ux": "0.162996773",
      "uy": "-0.001615047"
    },
    {
      "cx": "1.413250369",
      "cy": "1.051074187",
      "ux": "0.162985508",
      "uy": "0.002506137"
    },
    {
      "cx": "0.886860900",
      "cy": "0.521086230",
      "ux": "0.036119824",
      "uy": "0.158952555"
    },
    {
      "cx": "1.469458172",
      "cy": "0.376336247",
      "ux": "0.159272256",
      "uy": "0.034682919"
    },
    {
      "cx": "0.788947737",
      "cy": "0.209015059",
      "ux": "0.036119825",
      "uy": "0.158952555"
    },
    {
      "cx": "0.499106943",
      "cy": "0.404757479",
      "ux": "0.036119825",
      "uy": "0.158952555"
    },
    {
      "cx": "0.597020105",
      "cy": "0.716828655",
      "ux": "0.036119824",
      "uy": "0.158952555"
    },
    {
      "cx": "1.741521641",
      "cy": "0.723234384",
      "ux": "0.011546091",
      "uy": "0.162595339"
    },
    {
      "cx": "1.175244097",
      "cy": "0.195239101",
      "ux": "0.159272255",
      "uy": "0.034682923"
    },
    {
      "cx": "1.350177628",
      "cy": "1.376152462",
      "ux": "0.162985508",
      "uy": "0.002506137"
    },
    {
      "cx": "1.401333090",
      "cy": "0.724842833",
      "ux": "0.162985508",
      "uy": "0.002506137"
    },
    {
      "cx": "1.676131126",
      "cy": "1.382306527",
      "ux": "0.162985507",
      "uy": "0.002506144"
    },
    {
      "cx": "0.352136504",
      "cy": "1.422860031",
      "ux": "0.162996751",
      "uy": "-0.001617275"
    },
    {
      "cx": "1.008160427",
      "cy": "1.823580057",
      "ux": "0.162996773",
      "uy": "-0.001615048"
    },
    {
      "cx": "0.677803778",
      "cy": "1.386472653",
      "ux": "0.162996773",
      "uy": "-0.001615047"
    },
    {
      "cx": "0.223928928",
      "cy": "1.098106445",
      "ux": "0.162996751",
      "uy": "-0.001617270"
    }
  ]
}

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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