Université de Fribourg

On Split B1-EPG Graphs

Deniz, Zakir ; Nivelle, Simon ; Ries, Bernard ; Schindl, David

In: Lecture Notes in Computer Science, 2018, vol. 10807, p. 361-375

We consider the following problem: can a certain graph parameter of some given graph G be reduced by at least d, for some integer d, via at most k graph operations from some specified set S, for some given integer k? As graph parameters we take the chromatic number and the clique number. We let the set S consist of either an edge contraction or a vertex deletion. As all these problems are...

Université de Fribourg

On contact graphs of paths on a grid

Deniz, Zakir ; Galby, Esther ; Munaro, Andrea ; Ries, Bernard

In: Lecture Notes in Computer Science, 2018, vol. 11282, p. 317-330

In this paper we consider Contact graphs of Paths on a Grid (CPG graphs), i.e. graphs for which there exists a family of interiorly disjoint paths on a grid in one-to-one correspondence with their vertex set such that two vertices are adjacent if and only if the corresponding paths touch at a grid-point. Our class generalizes the well studied class of VCPG graphs (see [1]). We examine CPG...