English

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

Data Structures and Algorithms 2023-07-28 v1 Discrete Mathematics Combinatorics

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 C5C_5-free or C6C_6-free graphs, and, (C4,Cs)(C_4,C_s)-free graphs where s{3,7,8,9}s \in \{3,7,8,9\}. We extend their result proving that it is polynomial-time solvable for (C4,Cs)(C_4,C_s)-free graphs, for any constant ss, and for (C3,C7)(C_3,C_7)-free graphs. Our results also hold for the more general problem List 3-Colouring.

Keywords

Cite

@article{arxiv.2307.15036,
  title  = {3-Coloring $C_4$ or $C_3$-free Diameter Two Graphs},
  author = {Tereza Klimošová and Vibha Sahlot},
  journal= {arXiv preprint arXiv:2307.15036},
  year   = {2023}
}

Comments

14 pages. Revised version accepted to 18th Algorithms and Data Structures Symposium (WADS 2023)

R2 v1 2026-06-28T11:42:07.738Z