A note on the circular chromatic number of circular perfect planar graphs
نویسنده
چکیده
Computing the circular chromatic number of a given planar graph is NP-complete, as it is already NP-complete to compute its chromatic number. In this note, we prove that the circular clique number of a planar graph, and therefore the circular chromatic number of a circular perfect graph, is computable in O(ne) time; outerplanar graphs are circular perfect.
منابع مشابه
Claw-free circular-perfect graphs
The circular chromatic number of a graph is a well-studied refinement of the chromatic number. Circular-perfect graphs form a superclass of perfect graphs defined by means of this more general coloring concept. This paper studies claw-free circular-perfect graphs. First we prove that ifG is a connected claw-free circular-perfect graph with χ(G) > ω(G), then min{α(G), ω(G)} = 2. We use this resu...
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