Pack n 1 × 2 dominoes into a square container with boundary contact allowed and disjoint interiors, minimising the side length of the container square.
Formal definition
ContainerThe editor and certificate normalise the container to the unit square [0,1]², while public scores are reported in the literature's 1 × 2 domino scale. Boundary contact is allowed.
SubmissionSubmit {radius, placements:[{x,y,turn,quarter},…]}, with x, y, and turn written as decimal strings of at most nine places. Here radius is the short side of each domino inside the unit-square container, so the container side length is 1/radius. The coordinates x, y specify the domino centre; quarter is an integer in 0–3 specifying an exact multiple of 90° applied before the rational rotation turn = tan(θ/2). Coordinates and turn must lie in [−4, 4], with 0 < radius ≤ 4.
ConstraintsExactly n congruent dominoes lie wholly inside the container with pairwise disjoint interiors. Dominoes may rotate independently by arbitrary angles.
PrecisionInput decimals are parsed as exact rationals, with zero floating-point tolerance in feasibility checks.
ObjectiveContainer square side = 1/r (where r is the domino's short side inside the unit square), where smaller is better. Pages, leaderboards, and literature records share this unit with automatic conversion.
Getting a feel for it
Literature targets and coordinate certificates
Literature targets are converted at their published precision, while nine-decimal coordinate certificates are stored and displayed alongside the source values.
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/dominoes-in-square.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/dominoes-in-square.json
BibTeX (click to copy)
@misc{minmaxarena-dominoes-in-square-2026-10,
title = {{Dominoes in a square} (P90)},
author = {{MinMax Arena}},
year = {2026},
note = {Machine-verified records, 2026-10 edition},
url = {https://minmaxarena.com/data/editions/2026-10/dominoes-in-square.json},
license = {CC BY 4.0}
}
DISCUSSION
Discussion
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Grouped by player and sub-problem, showing the latest note first. Earlier versions and replies are preserved; click any note to read or reply. Notes can be published alongside record-breaking submissions.