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» Computing the Girth of a Planar Graph
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WG
2007
Springer
14 years 1 months ago
Complexity and Approximation Results for the Connected Vertex Cover Problem
We study a variation of the vertex cover problem where it is required that the graph induced by the vertex cover is connected. We prove that this problem is polynomial in chordal g...
Bruno Escoffier, Laurent Gourvès, Jé...
GD
2008
Springer
13 years 8 months ago
Crossing and Weighted Crossing Number of Near-Planar Graphs
A nonplanar graph G is near-planar if it contains an edge e such that G − e is planar. The problem of determining the crossing number of a near-planar graph is exhibited from di...
Sergio Cabello, Bojan Mohar
STOC
2010
ACM
295views Algorithms» more  STOC 2010»
14 years 16 days ago
Approximation Schemes for Steiner Forest on Planar Graphs and Graphs of Bounded Treewidth
We give the first polynomial-time approximation scheme (PTAS) for the Steiner forest problem on planar graphs and, more generally, on graphs of bounded genus. As a first step, w...
MohammadHossein Bateni, MohammadTaghi Hajiaghayi a...
GD
2009
Springer
14 years 9 days ago
On Planar Supports for Hypergraphs
A graph G is a support for a hypergraph H = (V, S) if the vertices of G correspond to the vertices of H such that for each hyperedge Si ∈ S the subgraph of G induced by Si is co...
Kevin Buchin, Marc J. van Kreveld, Henk Meijer, Be...
FCT
2009
Springer
13 years 11 months ago
Reachability in K3, 3-Free Graphs and K5-Free Graphs Is in Unambiguous Log-Space
We show that the reachability problem for directed graphs that are either K3,3-free or K5-free is in unambiguous log-space, UL coUL. This significantly extends the result of Bour...
Thomas Thierauf, Fabian Wagner