Competition Numbers of a Kind of Pseudo-Halin Graphs
- 1 School of Mathematics and Information Science, Shijiazhuang University, Shijiazhuang, China
- 2 School of Mathematics and Information Science, Shijiazhuang University, Shijiazhuang, China
- 3 School of Mathematics and Information Science, Shijiazhuang University, Shijiazhuang, China
- 4 School of Mathematics and Information Science, Shijiazhuang University, Shijiazhuang, China
Abstract
For any graph G , G together with sufficiently many isolated vertices is the competition graph of some acyclic digraph. The competition number k ( G) of a graph G is defined to be the smallest number of such isolated vertices. In general, it is hard to compute the competition number k ( G) for a graph G and chara - cterizing a graph by its competition number has been one of important research problems in the study of competition graphs. A 2-connected planar graph G with minimum degree at least 3 is a pseudo-Halin graph if deleting the edges on the boundary of a single face f 0 yields a tree. It is a Halin graph if the vertices of f 0 all have degree 3 in G . In this paper, we compute the competition numbers of a kind of pseudo-Halin graphs.
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