Rainbow subgraphs in edge-colored planar and outerplanar graphs
Július Czap · Discrete Mathematics Letters · 2023
Let G be a class of graphs.The strong rainbow number of the graph H in G is the minimum number of colors k such that every graph G ∈ G admits an edge coloring with at most k colors in which all copies of H are rainbow (i.e., all edges of H have different colors).In this paper, it is shown that the strong rainbow number of any 2-connected graph H in the class of outerplanar graphs is bounded from above by a constant (depending only on H).