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 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].
|Title of host publication||24th Annual European Symposium on Algorithms (ESA 2016)|
|Editors||Piotr Sankowski, Christos Zaroliagis|
|Place of Publication||Dagstuhl|
|Number of pages||14|
|Publication status||Published - 2016|
|Series||Leibniz International Proceedings in Informatics|