Marx, D. and Razgon, Igor (2009) Constant ratio fixed-parameter approximation of the edge multicut problem. In: Fiat, A. and Sanders, P. (eds.) Algorithms. Berlin, Germany: Springer Verlag, pp. 647-658. ISBN 9783642041280.
Abstract
The input of the Edge Multicut problem consists of an undirected graph G and pairs of terminals {s 1,t 1}, ..., {s m ,t m }; the task is to remove a minimum set of edges such that s i and t i are disconnected for every 1 ≤ i ≤ m. The parameterized complexity of the problem, parameterized by the maximum number k of edges that are allowed to be removed, is currently open. The main result of the paper is a parameterized 2-approximation algorithm: in time f(k)·n O(1), we can either find a solution of size 2k or correctly conclude that there is no solution of size k. The proposed algorithm is based on a transformation of the Edge Multicut problem into a variant of parameterized Max-2-SAT problem, where the parameter is related to the number of clauses that are not satisfied. It follows from previous results that the latter problem can be 2-approximated in a fixed-parameter time; on the other hand, we show here that it is W[1]-hard. Thus the additional contribution of the present paper is introducing the first natural W[1]-hard problem that is constant-ratio fixed-parameter approximable.
Metadata
Item Type: | Book Section |
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School: | Birkbeck Faculties and Schools > Faculty of Science > School of Computing and Mathematical Sciences |
Depositing User: | Sarah Hall |
Date Deposited: | 01 Aug 2013 15:34 |
Last Modified: | 09 Aug 2023 12:34 |
URI: | https://eprints.bbk.ac.uk/id/eprint/7921 |
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