Finer Tight Bounds for Coloring on Clique-Width

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Bibliographic Details
Title: Finer Tight Bounds for Coloring on Clique-Width
Authors: Michael Lampis
Contributors: Michael Lampis
Source: SIAM Journal on Discrete Mathematics. 34:1538-1558
Publication Status: Preprint
Publisher Information: Society for Industrial & Applied Mathematics (SIAM), 2020.
Publication Year: 2020
Subject Terms: FOS: Computer and information sciences, Programmation, Clique-width, 0211 other engineering and technologies, 0102 computer and information sciences, 02 engineering and technology, Computational Complexity (cs.CC), 01 natural sciences, organisation des données, Computer Science - Computational Complexity, Computer Science - Data Structures and Algorithms, SETH, Coloring, Data Structures and Algorithms (cs.DS), ddc:004, logiciels
Description: We revisit the complexity of the classical $k$-Coloring problem parameterized by clique-width. This is a very well-studied problem that becomes highly intractable when the number of colors $k$ is large. However, much less is known on its complexity for small, concrete values of $k$. In this paper, we completely determine the complexity of $k$-Coloring parameterized by clique-width for any fixed $k$, under the SETH. Specifically, we show that for all $k\ge 3,��>0$, $k$-Coloring cannot be solved in time $O^*((2^k-2-��)^{cw})$, and give an algorithm running in time $O^*((2^k-2)^{cw})$. Thus, if the SETH is true, $2^k-2$ is the "correct" base of the exponent for every $k$. Along the way, we also consider the complexity of $k$-Coloring parameterized by the related parameter modular treewidth ($mtw$). In this case we show that the "correct" running time, under the SETH, is $O^*({k\choose \lfloor k/2\rfloor}^{mtw})$. If we base our results on a weaker assumption (the ETH), they imply that $k$-Coloring cannot be solved in time $n^{o(cw)}$, even on instances with $O(\log n)$ colors.
To appear in ICALP 2018
Document Type: Article
Conference object
File Description: application/pdf
Language: English
ISSN: 1095-7146
0895-4801
DOI: 10.1137/19m1280326
DOI: 10.48550/arxiv.1804.07975
DOI: 10.4230/lipics.icalp.2018.86
Access URL: https://drops.dagstuhl.de/opus/volltexte/2018/9090/pdf/LIPIcs-ICALP-2018-86.pdf
http://arxiv.org/abs/1804.07975
https://dblp.uni-trier.de/db/journals/siamdm/siamdm34.html#Lampis20
https://epubs.siam.org/doi/pdf/10.1137/19M1280326
https://doi.org/10.1137/19M1280326
https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICALP.2018.86
Rights: CC BY
arXiv Non-Exclusive Distribution
Accession Number: edsair.doi.dedup.....9810db4144baebfed6c46fe1a03e0dce
Database: OpenAIRE
Description
Abstract:We revisit the complexity of the classical $k$-Coloring problem parameterized by clique-width. This is a very well-studied problem that becomes highly intractable when the number of colors $k$ is large. However, much less is known on its complexity for small, concrete values of $k$. In this paper, we completely determine the complexity of $k$-Coloring parameterized by clique-width for any fixed $k$, under the SETH. Specifically, we show that for all $k\ge 3,��>0$, $k$-Coloring cannot be solved in time $O^*((2^k-2-��)^{cw})$, and give an algorithm running in time $O^*((2^k-2)^{cw})$. Thus, if the SETH is true, $2^k-2$ is the "correct" base of the exponent for every $k$. Along the way, we also consider the complexity of $k$-Coloring parameterized by the related parameter modular treewidth ($mtw$). In this case we show that the "correct" running time, under the SETH, is $O^*({k\choose \lfloor k/2\rfloor}^{mtw})$. If we base our results on a weaker assumption (the ETH), they imply that $k$-Coloring cannot be solved in time $n^{o(cw)}$, even on instances with $O(\log n)$ colors.<br />To appear in ICALP 2018
ISSN:10957146
08954801
DOI:10.1137/19m1280326