Abstract
In this paper we study some connectivity augmentation problems. We want to make planar graphs 2-vertex (or 2-edge) connected by adding edges such that the resulting graphs remain planar. We show that it is NP-hard to find a minimum-cardinality augmentation that makes a planar graph 2-edge connected. This was known for 2-vertex connectivity. We further show that both problems are hard in a geometric setting, even when restricted to trees. For the special case of convex geometric graphs we give efficient algorithms.
We also study the following related problem. Given a plane geometric graph G, two vertices s and t of G, and an integer k, how many edges have to be added to G such that G contains k edge- (or vertex-) disjoint s-t paths? For k=2 we give optimal worst-case bounds; for k=3 we characterize all cases that have a solution.
Original language | English |
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Title of host publication | Abstracts 24th European Workshop on Computational Geometry (EuroCG'08, Nancy, France, March 18-20, 2008) |
Editors | S. Petitjean |
Place of Publication | Vandoeuvre-lès-Nancy |
Publisher | LORIA |
Pages | 71-74 |
Publication status | Published - 2008 |