It is known to be NP-hard to decide whether a graph can be made chordal by the deletion of k vertices or by the deletion of k edges. Here we present a uniformly polynomial-time alg...
Given an arbitrary graph G = (V, E) and an additional set of admissible edges F, the Chordal Sandwich problem asks whether there exists a chordal graph (V, E F ) such that F F. ...
Cluster Editing is transforming a graph by at most k edge insertions or deletions into a disjoint union of cliques. This problem is fixed-parameter tractable (FPT). Here we comput...
In the precoloring extension problem (PrExt) a graph is given with some of the vertices having a preassigned color and it has to be decided whether this coloring can be extended to...