The most uniform sampling mesh in the unit square
Place n points in the unit square. Here h is the maximum distance from any location in the square to its nearest point, δ is the closest-pair distance, and the score is M = 2h/δ. Make M as small as possible.
Formal definition
- ContainerThe unit square, with (0, 0) at the lower-left corner and (1, 1) at the upper-right
- SubmissionExactly n points, each coordinate a decimal with at most nine places; no two points may coincide
- Covering radiush(P) is the distance from the worst-covered location in the square to its nearest submitted point
- Separationδ(P) is the distance between the closest pair of submitted points
- ScoreM(P) penalizes both large holes and close pairs; internally M(P)² = 4h(P)²/δ(P)² is computed exactly, then rounded upward at 10⁻¹⁵
- ObjectiveMake M(P) as small as possible over all legal point sets P
Getting a feel for it
An analogy: siting base stations
Think of the n points as n base stations. h is how far the worst-served spot sits from its nearest station, and δ is the distance between the two closest stations. M = 2h/δ penalizes both large uncovered holes and crowded pairs.
Where the room for improvement is
A square grid gives M = √2 ≈ 1.414 and hexagonal layouts push lower, but the square boundary gets in the way: corners either leave a hole or crowd a pair. Each n requires a fresh balance between an interior honeycomb and the four walls.
Where the frontier is
Our paper proves the lower bound M ≥ 2/√3 for n ≥ 5 and classifies all n ≥ 10 that achieve equality. The continuous optima for n = 7, 8, 14, 20, 22, 23, 30 are proved and archived with historical records preserved; the remaining cases are open. Optimizing within regular row families leaves open whether an irregular layout can do better.
SourceCurrent best solutions by n
Each parameter n is an independently scored sub-problem. Select any card to inspect the current record construction or submit a stronger solution.
Discussion (3) ↓Data and citation
All sub-problems in this family — authoritative scores, proof status, coordinates, and sources — are published at the stable URL below under CC BY 4.0. Because scores update as records fall, please cite the file's generatedAt timestamp.
GET https://minmaxarena.com/data/uniform-mesh.json
Cite the frozen 2026-10 edition: live records change, whereas a frozen edition stays fixed and reproducible.
GET https://minmaxarena.com/data/editions/2026-10/uniform-mesh.json
BibTeX (click to copy)
@misc{minmaxarena-uniform-mesh-2026-10,
title = {{The most uniform sampling mesh in the unit square} (P56)},
author = {{MinMax Arena}},
year = {2026},
note = {Machine-verified records, 2026-10 edition},
url = {https://minmaxarena.com/data/editions/2026-10/uniform-mesh.json},
license = {CC BY 4.0}
}Discussion
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