On cliques of Helly Circular-arc Graphs
A circular-arc graph is the intersection graph of a set of arcs on the circle. It is a Helly circular-arc graph if it has a Helly model, where every maximal clique is the set of arcs that traverse some clique point on the circle. A clique model is a Helly model that identifies one clique point for e...
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15710653_v30_nC_p117_Lin http://hdl.handle.net/20.500.12110/paper_15710653_v30_nC_p117_Lin |
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paper:paper_15710653_v30_nC_p117_Lin2023-06-08T16:24:23Z On cliques of Helly Circular-arc Graphs Lin, Min Chih Soulignac, Francisco Juan algorithms clique graphs Helly circular-arc graphs maximum weight cliques proper Helly circular-arc graphs A circular-arc graph is the intersection graph of a set of arcs on the circle. It is a Helly circular-arc graph if it has a Helly model, where every maximal clique is the set of arcs that traverse some clique point on the circle. A clique model is a Helly model that identifies one clique point for each maximal clique. A Helly circular-arc graph is proper if it has a Helly model where no arc is a subset of another. In this paper, we show that the clique intersection graphs of Helly circular-arc graphs are related to the proper Helly circular-arc graphs. This yields the first polynomial (linear) time recognition algorithm for the clique graphs of Helly circular-arc graphs. Next, we develop an O (n) time algorithm to obtain a clique model of Helly model, improving the previous O (n2) bound. This gives a linear-time algorithm to find a proper Helly model for the clique graph of a Helly circular-arc graph. As an application, we find a maximum weighted clique of a Helly circular-arc graph in linear time. © 2008 Elsevier B.V. All rights reserved. Fil:Lin, M.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Soulignac, F.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15710653_v30_nC_p117_Lin http://hdl.handle.net/20.500.12110/paper_15710653_v30_nC_p117_Lin |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
algorithms clique graphs Helly circular-arc graphs maximum weight cliques proper Helly circular-arc graphs |
spellingShingle |
algorithms clique graphs Helly circular-arc graphs maximum weight cliques proper Helly circular-arc graphs Lin, Min Chih Soulignac, Francisco Juan On cliques of Helly Circular-arc Graphs |
topic_facet |
algorithms clique graphs Helly circular-arc graphs maximum weight cliques proper Helly circular-arc graphs |
description |
A circular-arc graph is the intersection graph of a set of arcs on the circle. It is a Helly circular-arc graph if it has a Helly model, where every maximal clique is the set of arcs that traverse some clique point on the circle. A clique model is a Helly model that identifies one clique point for each maximal clique. A Helly circular-arc graph is proper if it has a Helly model where no arc is a subset of another. In this paper, we show that the clique intersection graphs of Helly circular-arc graphs are related to the proper Helly circular-arc graphs. This yields the first polynomial (linear) time recognition algorithm for the clique graphs of Helly circular-arc graphs. Next, we develop an O (n) time algorithm to obtain a clique model of Helly model, improving the previous O (n2) bound. This gives a linear-time algorithm to find a proper Helly model for the clique graph of a Helly circular-arc graph. As an application, we find a maximum weighted clique of a Helly circular-arc graph in linear time. © 2008 Elsevier B.V. All rights reserved. |
author |
Lin, Min Chih Soulignac, Francisco Juan |
author_facet |
Lin, Min Chih Soulignac, Francisco Juan |
author_sort |
Lin, Min Chih |
title |
On cliques of Helly Circular-arc Graphs |
title_short |
On cliques of Helly Circular-arc Graphs |
title_full |
On cliques of Helly Circular-arc Graphs |
title_fullStr |
On cliques of Helly Circular-arc Graphs |
title_full_unstemmed |
On cliques of Helly Circular-arc Graphs |
title_sort |
on cliques of helly circular-arc graphs |
publishDate |
2008 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15710653_v30_nC_p117_Lin http://hdl.handle.net/20.500.12110/paper_15710653_v30_nC_p117_Lin |
work_keys_str_mv |
AT linminchih oncliquesofhellycirculararcgraphs AT soulignacfranciscojuan oncliquesofhellycirculararcgraphs |
_version_ |
1768544749121175552 |