Document Open Access Logo

Shadoks Approach to Parallel Reconfiguration of Triangulations (CG Challenge)

Authors Guilherme D. da Fonseca , Fabien Feschet , Yan Gerard

PDF

File

Thumbnail PDF
PDF
LIPIcs.SoCG.2026.107.pdf
  • Filesize: 0.74 MB
  • 7 pages

Document Identifiers

Related Versions

Subject Classification

ACM Subject Classification
  • Theory of computation → Computational geometry
Keywords
  • Exact algorithm
  • SAT
  • MaxSAT
  • heuristic
  • computational geometry

Metrics

Abstract

We describe the methods used by Team Shadoks to win the CG:SHOP 2026 Challenge on parallel reconfiguration of planar triangulations.  Our approach combines exact methods based on SAT with several greedy heuristics, and also makes use of SAT and MaxSAT for solution improvement.

Cite As Get BibTex

Guilherme D. da Fonseca, Fabien Feschet, and Yan Gerard. Shadoks Approach to Parallel Reconfiguration of Triangulations (CG Challenge). In 42nd International Symposium on Computational Geometry (SoCG 2026). Leibniz International Proceedings in Informatics (LIPIcs), Volume 367, pp. 107:1-107:7, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026) https://doi.org/10.4230/LIPIcs.SoCG.2026.107

Author Details

Guilherme D. da Fonseca
  • LIS, Aix-Marseille Université, France
Fabien Feschet
  • LIMOS, Université Clermont Auvergne, France
Yan Gerard
  • LIMOS, Université Clermont Auvergne, France

Acknowledgements

We would like to thank the Challenge organizers and other competitors for their time, feedback, and making this whole event possible. We would like to thank Hélène Toussaint, Raphaël Amato, Boris Lonjon, and William Guyot-Lénat from LIMOS, as well as the Qarma and TALEP teams and Manuel Bertrand from LIS, who continue to make the computational resources of the LIMOS and LIS clusters available to our research. We would also like to thank Aldo Gonzalez-Lorenzo for the very useful discussion on SAT models.

Supplementary Materials

References

  1. Oswin Aichholzer, Brad Ballinger, Therese Biedl, Mirela Damian, Erik D Demaine, Matias Korman, Anna Lubiw, Jayson Lynch, Josef Tkadlec, and Yushi Uno. Reconfiguration of non-crossing spanning trees, 2022. URL: https://doi.org/10.48550/arXiv.2206.03879.
  2. Oswin Aichholzer, Joseph Dorfer, Sándor P. Fekete, Phillip Keldenich, Peter Kramer, and Stefan Schirra. Central triangulation under parallel flip operations: The CG:SHOP challenge 2026, 2026. URL: https://arxiv.org/abs/2603.18812.
  3. Florent Avellaneda. A short description of the solver EvalMaxSAT. MaxSAT Evaluation, 8:364, 2020. Google Scholar
  4. Lorenzo Battini and Marko Milenković. ETH flippers approach to parallel reconfiguration of triangulations: SAT formulation and heuristics. In Proceedings of the Symposium on Computational Geometry (SoCG), 2026. URL: https://doi.org/10.4230/LIPIcs.SoCG.2026.105.
  5. Armin Biere, Tobias Faller, Katalin Fazekas, Mathias Fleury, Nils Froleyks, and Florian Pollitt. CaDiCaL 2.0. In Computer Aided Verification - 36th International Conference, CAV, volume 14681 of LNCS, pages 133-152, 2024. URL: https://doi.org/10.1007/978-3-031-65627-9_7.
  6. P Biró, D Manlove, and R Rizzi. Maximum weight cycle packing in optimal kidney exchange programs, university of glasgow, department of computing science. Technical report, Technical Report TR-2009-298, 2009. Google Scholar
  7. Jacobus Conradi, Benedikt Kolbe, Philip Mayer, Jonas Sauer, and Jack Spalding-Jamieson. Engineering greedy heuristics and simulated annealing methods for the median triangulation under the parallel flip distance. In Proceedings of the Symposium on Computational Geometry (SoCG), 2026. URL: https://doi.org/10.4230/LIPIcs.SoCG.2026.106.
  8. Ruy Fabila-Monroy, Clemens Huemer, and Dieter Mitsche. The number of empty four-gons in random point sets. Electronic Notes in Discrete Mathematics, 46:161-168, 2014. URL: https://doi.org/10.1016/j.endm.2014.08.022.
  9. Jaegun Lee, Seokyun Kang, Hyeonseok Lee, Hyeyun Yang, and Taehoon Ahn. CG#Hunters approach to central triangulation under parallel flip operations. In Proceedings of the Symposium on Computational Geometry (SoCG), 2026. URL: https://doi.org/10.4230/LIPIcs.SoCG.2026.108.
  10. Alexander Pilz. Flip distance between triangulations of a planar point set is APX-hard. Computational Geometry, 47(5):589-604, 2014. URL: https://doi.org/10.1016/j.comgeo.2014.01.001.
  11. Daniel D. Sleator and William P. Tarjan, Robert E.and Thurston. Rotation distance, triangulations, and hyperbolic geometry. In Proceedings of the eighteenth annual ACM symposium on Theory of computing, pages 122-135, 1986. Google Scholar
  12. O. Tange. GNU parallel - The command-line power tool. ;login: The USENIX Magazine, 36(1):42-47, February 2011. URL: http://www.gnu.org/s/parallel.
  13. Andy B Yoo, Morris A Jette, and Mark Grondona. Slurm: Simple linux utility for resource management. In Workshop on job scheduling strategies for parallel processing, pages 44-60, 2003. URL: https://doi.org/10.1007/10968987_3.
Any Issues?
X

Feedback on the Current Page

CAPTCHA

Thanks for your feedback!

Feedback submitted to Dagstuhl Publishing

Could not send message

Please try again later or send an E-mail
© 2023-2026 Schloss Dagstuhl – LZI GmbH Schloss Dagstuhl – LZI GmbH About DROPS Imprint Privacy Contact