M_2-edge colorings of cacti and graph joins
Július Czap, Jaroslav Ivančo, Peter Šugerek · Discussiones Mathematicae Graph Theory · 2015
An edge coloring ϕ of a graph G is called an M 2 -edge coloring if |ϕ(v)| ≤ 2 for every vertex v of G, where ϕ(v) is the set of colors of edges incident with v. Let K 2 (G) denote the maximum number of colors used in an M 2 -edge coloring of G.In this paper we determine K 2 (G) for trees, cacti, complete multipartite graphs and graph joins.