Graph minors. XIII: the disjoint paths problem
Journal of Combinatorial Theory Series B
A Fast and High Quality Multilevel Scheme for Partitioning Irregular Graphs
SIAM Journal on Scientific Computing
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
On Clustering Using Random Walks
FST TCS '01 Proceedings of the 21st Conference on Foundations of Software Technology and Theoretical Computer Science
Hierarchy of surface models and irreducible triangulations
Computational Geometry: Theory and Applications
Restricted mesh simplification using edge contractions
COCOON'06 Proceedings of the 12th annual international conference on Computing and Combinatorics
Edge separability-based circuit clustering with application to multilevel circuit partitioning
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Contractions of planar graphs in polynomial time
ESA'10 Proceedings of the 18th annual European conference on Algorithms: Part I
Edge contractions in subclasses of chordal graphs
TAMC'11 Proceedings of the 8th annual conference on Theory and applications of models of computation
Edge contractions in subclasses of chordal graphs
Discrete Applied Mathematics
Finding small separators in linear time via treewidth reduction
ACM Transactions on Algorithms (TALG)
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For a fixed graph H, the H-Contractibility problem asks if a graph is H-contractible, i.e., can be transformed into H via a series of edge contractions. The computational complexity classification of this problem is still open. So far, H has a dominating vertex in all cases known to be polynomially solvable, whereas H does not have such a vertex in all cases known to be NP-complete. Here, we present a class of graphs H with a dominating vertex for which H-Contractibility is NP-complete. We also present a new class of graphs H for which H-Contractibility is polynomially solvable. Furthermore, we study the (H,v)-Contractibility problem, where v is a vertex of H. The input of this problem is a graph G and an integer k. The question is whether G is H-contractible such that the "bag" of G corresponding to v contains at least k vertices. We show that this problem is NP-complete whenever H is connected and v is not a dominating vertex of H.