Graphs of intersections of closed polygonal chains
In the paper such subclass of string graphs as intersection graphs of closed polygonal chains (class of CPC-graphs) was considered, necessary conditions for belonging to that class, forbidden subgraphs and operations with graphs which preserve belonging to the CPC class were found. Considered questi...
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Format: | Article |
Language: | Belarusian |
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Belarusian State University
2021-04-01
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Series: | Журнал Белорусского государственного университета: Математика, информатика |
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Online Access: | https://journals.bsu.by/index.php/mathematics/article/view/3379 |
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author | Nikolai P. Prochorov Ekaterina N. Dul |
author_facet | Nikolai P. Prochorov Ekaterina N. Dul |
author_sort | Nikolai P. Prochorov |
collection | DOAJ |
description | In the paper such subclass of string graphs as intersection graphs of closed polygonal chains (class of CPC-graphs) was considered, necessary conditions for belonging to that class, forbidden subgraphs and operations with graphs which preserve belonging to the CPC class were found. Considered question about the existence of k-regular CPC-graphs, particularly, pairs (k, n), such that there exists k-regular CPC-graph on n vertexes were found, proved that there are infinitely many k-regular CPC-graphs for any k ∈ N, estimations for the number of k, such that k-regular graph on n vertexes exists, were given. Algorithmic questions in the class of CPC-graphs were investigated. It was proved that independent and dominating set problems, coloring problem and the problem about maximal cycle are NP-hard in the class of CPC-graphs, and problem of recognition of the CPC-graphs belongs to the PSPACE class. |
first_indexed | 2024-12-24T01:11:35Z |
format | Article |
id | doaj.art-afaf53c7b7e34c0ab0be3c74a03baa18 |
institution | Directory Open Access Journal |
issn | 2520-6508 2617-3956 |
language | Belarusian |
last_indexed | 2024-12-24T01:11:35Z |
publishDate | 2021-04-01 |
publisher | Belarusian State University |
record_format | Article |
series | Журнал Белорусского государственного университета: Математика, информатика |
spelling | doaj.art-afaf53c7b7e34c0ab0be3c74a03baa182022-12-21T17:22:57ZbelBelarusian State UniversityЖурнал Белорусского государственного университета: Математика, информатика2520-65082617-39562021-04-011546810.33581/2520-6508-2021-1-54-683379Graphs of intersections of closed polygonal chainsNikolai P. Prochorov0https://orcid.org/0000-0001-9725-299XEkaterina N. Dul1https://orcid.org/0000-0001-9073-7855Belarusian State University, 4 Niezaliežnasci Avenue, Minsk 220030, BelarusBelarusian State University, 4 Niezaliežnasci Avenue, Minsk 220030, BelarusIn the paper such subclass of string graphs as intersection graphs of closed polygonal chains (class of CPC-graphs) was considered, necessary conditions for belonging to that class, forbidden subgraphs and operations with graphs which preserve belonging to the CPC class were found. Considered question about the existence of k-regular CPC-graphs, particularly, pairs (k, n), such that there exists k-regular CPC-graph on n vertexes were found, proved that there are infinitely many k-regular CPC-graphs for any k ∈ N, estimations for the number of k, such that k-regular graph on n vertexes exists, were given. Algorithmic questions in the class of CPC-graphs were investigated. It was proved that independent and dominating set problems, coloring problem and the problem about maximal cycle are NP-hard in the class of CPC-graphs, and problem of recognition of the CPC-graphs belongs to the PSPACE class.https://journals.bsu.by/index.php/mathematics/article/view/3379intersection graphintersection graph of closed polygonal chainsregular graphnp-completenesspolynomial-time reduction |
spellingShingle | Nikolai P. Prochorov Ekaterina N. Dul Graphs of intersections of closed polygonal chains Журнал Белорусского государственного университета: Математика, информатика intersection graph intersection graph of closed polygonal chains regular graph np-completeness polynomial-time reduction |
title | Graphs of intersections of closed polygonal chains |
title_full | Graphs of intersections of closed polygonal chains |
title_fullStr | Graphs of intersections of closed polygonal chains |
title_full_unstemmed | Graphs of intersections of closed polygonal chains |
title_short | Graphs of intersections of closed polygonal chains |
title_sort | graphs of intersections of closed polygonal chains |
topic | intersection graph intersection graph of closed polygonal chains regular graph np-completeness polynomial-time reduction |
url | https://journals.bsu.by/index.php/mathematics/article/view/3379 |
work_keys_str_mv | AT nikolaipprochorov graphsofintersectionsofclosedpolygonalchains AT ekaterinandul graphsofintersectionsofclosedpolygonalchains |