,
Hsien-Chih Chang
,
Maarten Löffler
,
Tim Ophelders
,
Lena Schlipf
Creative Commons Attribution 4.0 International license
We study reconfiguration in curve arrangements, where a subset of the crossings are marked as switches which have three possible states, and the goal is to set the switches such that the resulting curve arrangement has few self-intersections, or few faces that are incident to the same curve multiple times (a.k.a. popular faces). Our results are that these problems are NP-hard, but FPT in the number of switches. Minimizing self-intersections is also FPT in the number of non-switchable crossings; for minimizing popular faces this problem remains open. Our results can be applied to generating curved nonograms, a type of logic puzzle that has received some attention lately. Specifically, our results make it possible to efficiently convert expert puzzles into advanced puzzles (or determine that this is impossible).
@InProceedings{brunck_et_al:LIPIcs.GD.2025.36,
author = {Brunck, Florestan and Chang, Hsien-Chih and L\"{o}ffler, Maarten and Ophelders, Tim and Schlipf, Lena},
title = {{Reconfiguration in Curve Arrangements to Reduce Self-Intersections and Popular Faces}},
booktitle = {33rd International Symposium on Graph Drawing and Network Visualization (GD 2025)},
pages = {36:1--36:18},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-403-1},
ISSN = {1868-8969},
year = {2025},
volume = {357},
editor = {Dujmovi\'{c}, Vida and Montecchiani, Fabrizio},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.GD.2025.36},
URN = {urn:nbn:de:0030-drops-250220},
doi = {10.4230/LIPIcs.GD.2025.36},
annote = {Keywords: Curve Arrangements, Reconfiguration, Curve Arrangements, NP-hardness, Fixed-Parameter Tractability, Puzzle Generation}
}