,
George Skretas
Creative Commons Attribution 4.0 International license
In this paper, we settle the main open question of [Michail, Skretas, Spirakis, ICALP'17], asking what is the family of two-dimensional geometric shapes that can be transformed into each other by a sequence of rotation operations, none of which disconnects the shape. The model represents programmable matter systems consisting of interconnected modules that perform the minimal mechanical operation of 90° rotations around each other. The goal is to transform an initial shape of modules A into a target shape B. Under the necessary assumptions that the given shapes are connected and have identical colourings on a checkered colouring of the grid, and using a seed of only constant size, we prove that any pair of such shapes can be transformed into each other within an optimal O(n²) rotation operations none of which disconnects the shape.
@InProceedings{connor_et_al:LIPIcs.SAND.2024.9,
author = {Connor, Matthew and Michail, Othon and Skretas, George},
title = {{All for One and One for All: An O(1)-Musketeers Universal Transformation for Rotating Robots}},
booktitle = {3rd Symposium on Algorithmic Foundations of Dynamic Networks (SAND 2024)},
pages = {9:1--9:20},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-315-7},
ISSN = {1868-8969},
year = {2024},
volume = {292},
editor = {Casteigts, Arnaud and Kuhn, Fabian},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SAND.2024.9},
URN = {urn:nbn:de:0030-drops-198874},
doi = {10.4230/LIPIcs.SAND.2024.9},
annote = {Keywords: programmable matter, universal transformation, reconfigurable robotics, shape formation, centralised algorithms}
}