Oriented vertex and arc colorings of outerplanar graphs
نویسندگان
چکیده
A homomorphism from an oriented graph G to an oriented graph H is an arc-preserving mapping φ from V (G) to V (H), that is φ(x)φ(y) is an arc in H whenever xy is an arc in G. The oriented chromatic number of G is the minimum order of an oriented graph H such that G has a homomorphism to H . The oriented chromatic index of G is the minimum order of an oriented graph H such that the line-digraph of G has a homomorphism to H . In this paper, we determine for every k 3 the oriented chromatic number and the oriented chromatic index of the class of oriented outerplanar graphs with girth at least k. © 2006 Elsevier B.V. All rights reserved.
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ورودعنوان ژورنال:
- Inf. Process. Lett.
دوره 100 شماره
صفحات -
تاریخ انتشار 2006