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arXiv · 2307.15036

3-Coloring $C_4$ or $C_3$-free Diameter Two Graphs

Tereza Klimošová·Vibha Sahlot
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Abstract

The question of whether 3-Coloring can be solved in polynomial-time for the diameter two graphs is a well-known open problem in the area of algorithmic graph theory. We study the problem restricted to graph classes that avoid cycles of given lengths as induced subgraphs. Martin et. al. [CIAC 2021] showed that the problem is polynomial-time solvable for $C_5$-free or $C_6$-free graphs, and, $(C_4,C_s)$-free graphs where $s \in \{3,7,8,9\}$. We extend their result proving that it is polynomial-time solvable for $(C_4,C_s)$-free graphs, for any constant $s$, and for $(C_3,C_7)$-free graphs. Our results also hold for the more general problem List 3-Colouring.

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Tereza Klimošová, Vibha Sahlot. 2023-07-27. 3-Coloring $C_4$ or $C_3$-free Diameter Two Graphs. https://arxiv.org/abs/2307.15036

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