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JOURNALS // Proceedings of the Yerevan State University, series Physical and Mathematical Sciences // Archive

Proceedings of the YSU, Physical and Mathematical Sciences, 2021 Volume 55, Issue 3, Pages 160–168 (Mi uzeru925)

Mathematics

Interval vertex-colorings of cactus graphs with restrictions on vertices

A. Kh. Sahakyan, R. R. Kamalian

Yerevan State University, Faculty of Informatics and Applied Mathematics

Abstract: An interval vertex-coloring of a graph $G$ is a coloring of the vertices of the graph with intervals of integers such that the intervals of any two adjacent vertices do not intersect. In this paper we consider the case, where for each vertex $v$ there is a length $l(v)$ and a set of colors $S(v),$ from which the colors should be and it is required to find an interval vertex-coloring $\gamma$ such that for each vertex $v$ the restrictions are met, i.e. $|\gamma(v)|=l(v),\gamma(v)\subseteq S(v)$. We will provide a pseudo-polynomial algorithm for cactus graphs. If it is impossible to have an interval vertex-coloring that satisfies all the restrictions, then the algorithm will tell that as well.

Keywords: cactus graphs, trees, interval vertex-coloring, list coloring, dynamic programming, pseudo-polynomial algorithm.

MSC: Primary 05C15; Secondary 68Q25

Received: 30.06.2021
Revised: 31.10.2021
Accepted: 14.11.2021

Language: English

DOI: 10.46991/PYSU:A/2021.55.3.160



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