Coloring directed cycles
Discrete Mathematics
2013-07-22 v1 Combinatorics
Abstract
Sopena in his survey [E. Sopena, The oriented chromatic number of graphs: A short survey, preprint 2013] writes, without any proof, that an oriented cycle can be colored with three colors if and only if , where is the number of forward arcs minus the number of backward arcs in . This is not true. In this paper we show that can be colored with three colors if and only if or does not contain three consecutive arcs going in the same direction.
Cite
@article{arxiv.1307.5186,
title = {Coloring directed cycles},
author = {Andrzej Szepietowski},
journal= {arXiv preprint arXiv:1307.5186},
year = {2013}
}