,
Ignaz Rutter
Creative Commons Attribution 4.0 International license
To date, the best circle graph recognition algorithm, due to Gioan et al. [E. Gioan et al., 2014] runs in almost linear time as it relies on a split decomposition algorithm [E. Gioan et al., 2014] that uses the union-find data-structure [B.A. Galler and M.J. Fischer, 1964; R. Tarjan, 1975]. We show that in the case of circle graphs, the PC-tree data-structure [W. K. Shih and W. L. Hsu, 1999] allows one to avoid the union-find data-structure to compute the split decomposition in linear time. As a consequence, we obtain the first linear-time recognition algorithm for circle graphs.
@InProceedings{paul_et_al:LIPIcs.STACS.2026.72,
author = {Paul, Christophe and Rutter, Ignaz},
title = {{Circle Graphs Can Be Recognized in Linear Time}},
booktitle = {43rd International Symposium on Theoretical Aspects of Computer Science (STACS 2026)},
pages = {72:1--72:20},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-412-3},
ISSN = {1868-8969},
year = {2026},
volume = {364},
editor = {Mahajan, Meena and Manea, Florin and McIver, Annabelle and Thắng, Nguy\~{ê}n Kim},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.STACS.2026.72},
URN = {urn:nbn:de:0030-drops-255614},
doi = {10.4230/LIPIcs.STACS.2026.72},
annote = {Keywords: graph classes, circle graphs, graph algorithms}
}