English

A 7/3-Approximation for Feedback Vertex Sets in Tournaments

Data Structures and Algorithms 2015-11-05 v1 Discrete Mathematics

Abstract

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\mathsf{NP}-hard to solve exactly, and Unique Games-hard to approximate by a factor better than 2. We present the first 7/37/3 approximation algorithm for this problem, improving on the previously best known ratio 5/25/2 given by Cai et al. [FOCS 1998, SICOMP 2001].

Keywords

Cite

@article{arxiv.1511.01137,
  title  = {A 7/3-Approximation for Feedback Vertex Sets in Tournaments},
  author = {Matthias Mnich and Virginia Vassilevska Williams and László A. Végh},
  journal= {arXiv preprint arXiv:1511.01137},
  year   = {2015}
}
R2 v1 2026-06-22T11:36:58.597Z