Edge partition of planar sraphs into two outerplanar graphs
Daniel Gonçalves · 2005
An outerplanar graph is a planar graph that can be embedded in the plane without crossing edges, in such a way that all the vertices are on the outer boundary. In this paper, we prove a conjecture of Chartrand, Geller, and Hedetniemi that any planar graph G=(V,E) has a bipartition of its edge set E = A ∪ B such that the graphs induced by these subsets, G[A] and G[B], are outerplanar.