A 7/3-Approximation for Feedback Vertex Sets in Tournaments
A 7/3-Approximation for Feedback Vertex Sets in Tournaments
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DOI:
10.4230/lipics.esa.2016.67
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发表时间:
2015-11
期刊:
影响因子:
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通讯作者:
Matthias Mnich;V. V. Williams-V.;László A. Végh
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文献类型:
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作者:
Matthias Mnich;V. V. Williams-V.;László A. Végh
We consider the minimum-weight feedback vertex set problem in tournaments: given a tournament with non-negative vertex weights, remove a minimum-weight set of vertices that intersects all cycles. This problem is $\mathsf{NP}$-hard to solve exactly, and Unique Games-hard to approximate by a factor better than 2. We present the first $7/3$ approximation algorithm for this problem, improving on the previously best known ratio $5/2$ given by Cai et al. [FOCS 1998, SICOMP 2001].