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...
| Main Authors: | , |
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| Format: | Article |
| Language: | Belarusian |
| Published: |
Belarusian State University
2021-04-01
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| Series: | Журнал Белорусского государственного университета: Математика, информатика |
| Subjects: | |
| Online Access: | https://journals.bsu.by/index.php/mathematics/article/view/3379 |
| Summary: | 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. |
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| ISSN: | 2520-6508 2617-3956 |