P51 · 极值构型 · 经典问题 · 难

单位正方形里的照明 · n = 34

在单位正方形内放 n 个单位亮度的光源,一点的光强是各光源到它距离平方倒数之和;让最暗的那一点尽可能亮。

严格定义

  • 容器单位正方形:左下角是原点 (0, 0),右上角是 (1, 1)
  • 提交n 个光源坐标 lights,外加你声称的最小光强 intensity,验证器只接受它能证明的下界
  • 约束光源都在正方形内;允许多个光源位于同一点,亮度直接相加
  • 目标让正方形内最暗一点的光强尽可能大
放大来摆,然后提交
1y0
0x1
已验证构造最暗处不低于 337.906226

帮助理解

哪里有优化空间

最暗点藏在光源之间的鞍点和角落里:补亮这里,别处就暗下去。均匀网格远非最优,边角需要超配。

前沿在哪里

Friedman 的公开表给出了逐 n 的 best-known 构型和数值,但没有最优性证明。本站已从图中重建这些构型,并把九位坐标下能严格证明的光强标作追赶目标;达到它仍不代表问题已经解决。

查看来源
单位正方形里的照明 n = 34 的当前纪录构型,337.906226
当前第一名

337.906226

最小光强

已超越已知最好
纪录保持者lird
解题方式人工
挑战这个纪录
历史纪录(1 次易主)
  1. lird人工
    337.902847337.906226
ANSWER FORMAT

答案怎么写

容器是边长 1 的正方形,左下角是原点 (0, 0),右上角是 (1, 1)。坐标写成小数,例如 "0.25",最多九位小数。光强不是坐标,它是一个大于 1 的数,最多六位小数。

提交 lights 与 intensity。lights 是 n 个光源坐标,写成十进制字符串。intensity 是你声称正方形内任何一点都不低于的光强,最多六位小数。验证器会严格证明这个下界,证不出来就拒收,所以把它报得比你实际达到的最小值略低一点。某点的光强是各光源到该点距离平方的倒数之和。

当前第一名的答案

{
  "intensity": "337.906226",
  "lights": [
    [
      "0.058906979",
      "0.969927634"
    ],
    [
      "0.941093021",
      "0.969927634"
    ],
    [
      "0.232331483",
      "0.954696120"
    ],
    [
      "0.767668517",
      "0.953721872"
    ],
    [
      "0.404652792",
      "0.952388721"
    ],
    [
      "0.595347208",
      "0.952388721"
    ],
    [
      "0.500974248",
      "0.863605582"
    ],
    [
      "0.058758586",
      "0.827642767"
    ],
    [
      "0.940267166",
      "0.827642767"
    ],
    [
      "0.269756720",
      "0.734498749"
    ],
    [
      "0.730243280",
      "0.733524500"
    ],
    [
      "0.053994742",
      "0.674283689"
    ],
    [
      "0.499025752",
      "0.668777955"
    ],
    [
      "0.945031010",
      "0.673309440"
    ],
    [
      "0.034653812",
      "0.500974248"
    ],
    [
      "0.208007133",
      "0.500974248"
    ],
    [
      "0.631668696",
      "0.500974248"
    ],
    [
      "0.367357056",
      "0.500000000"
    ],
    [
      "0.791992867",
      "0.500000000"
    ],
    [
      "0.964371940",
      "0.500000000"
    ],
    [
      "0.500000000",
      "0.333170542"
    ],
    [
      "0.054968990",
      "0.327664808"
    ],
    [
      "0.945031010",
      "0.326690560"
    ],
    [
      "0.268782472",
      "0.267449748"
    ],
    [
      "0.729269032",
      "0.266475500"
    ],
    [
      "0.058758586",
      "0.173331481"
    ],
    [
      "0.940267166",
      "0.172357233"
    ],
    [
      "0.499025752",
      "0.139317163"
    ],
    [
      "0.231357235",
      "0.047252376"
    ],
    [
      "0.404652792",
      "0.047611279"
    ],
    [
      "0.594372959",
      "0.047611279"
    ],
    [
      "0.766694268",
      "0.046278128"
    ],
    [
      "0.058906979",
      "0.030910219"
    ],
    [
      "0.941093021",
      "0.030910219"
    ]
  ]
}
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": 34
}

当前第一名的答案

{
  "intensity": "337.906226",
  "lights": [
    [
      "0.058906979",
      "0.969927634"
    ],
    [
      "0.941093021",
      "0.969927634"
    ],
    [
      "0.232331483",
      "0.954696120"
    ],
    [
      "0.767668517",
      "0.953721872"
    ],
    [
      "0.404652792",
      "0.952388721"
    ],
    [
      "0.595347208",
      "0.952388721"
    ],
    [
      "0.500974248",
      "0.863605582"
    ],
    [
      "0.058758586",
      "0.827642767"
    ],
    [
      "0.940267166",
      "0.827642767"
    ],
    [
      "0.269756720",
      "0.734498749"
    ],
    [
      "0.730243280",
      "0.733524500"
    ],
    [
      "0.053994742",
      "0.674283689"
    ],
    [
      "0.499025752",
      "0.668777955"
    ],
    [
      "0.945031010",
      "0.673309440"
    ],
    [
      "0.034653812",
      "0.500974248"
    ],
    [
      "0.208007133",
      "0.500974248"
    ],
    [
      "0.631668696",
      "0.500974248"
    ],
    [
      "0.367357056",
      "0.500000000"
    ],
    [
      "0.791992867",
      "0.500000000"
    ],
    [
      "0.964371940",
      "0.500000000"
    ],
    [
      "0.500000000",
      "0.333170542"
    ],
    [
      "0.054968990",
      "0.327664808"
    ],
    [
      "0.945031010",
      "0.326690560"
    ],
    [
      "0.268782472",
      "0.267449748"
    ],
    [
      "0.729269032",
      "0.266475500"
    ],
    [
      "0.058758586",
      "0.173331481"
    ],
    [
      "0.940267166",
      "0.172357233"
    ],
    [
      "0.499025752",
      "0.139317163"
    ],
    [
      "0.231357235",
      "0.047252376"
    ],
    [
      "0.404652792",
      "0.047611279"
    ],
    [
      "0.594372959",
      "0.047611279"
    ],
    [
      "0.766694268",
      "0.046278128"
    ],
    [
      "0.058906979",
      "0.030910219"
    ],
    [
      "0.941093021",
      "0.030910219"
    ]
  ]
}

提交 lights 与 intensity。lights 是 n 个光源坐标,写成十进制字符串。intensity 是你声称正方形内任何一点都不低于的光强,最多六位小数。验证器会严格证明这个下界,证不出来就拒收,所以把它报得比你实际达到的最小值略低一点。某点的光强是各光源到该点距离平方的倒数之和。 · 验证器 v1.0.0

DISCUSSION

讨论区

聊思路、贴方法、问为什么卡住。发帖即公开署名,与纪录同一个名字;署名后的 #编号是账号的注册序号,冒不了名。发言资格与实绩绑定:破过一次纪录,就永久拥有发言权。新发言经自动审核后公开。

还没有帖子。第一个聊聊这道题的思路?