Abstract
A feedback vertex set in an undirected graph is a subset of vertices removal of which leaves a graph with no cycles. Razgon (in: Proceedings of the 10th Scandinavian workshop on algorithm theory (SWAT 2006), pp. 160–171, 2006) gave a \(1.8899^n n^{O(1)}\)-time algorithm for finding a minimum feedback vertex set in an \(n\)-vertex undirected graph, which is the first exact algorithm for the problem that breaks the trivial barrier of \(2^n\). Later, Fomin et al. (Algorithmica 52:293–307, 2008) improved the result to \(1.7548^n n^{O(1)}\). In this paper, we further improve the result to \(1.7266^n n^{O(1)}\). Our algorithm is analyzed by the measure-and-conquer method. We get the improvement by designing new reductions based on biconnectivity of instances and introducing a new measure scheme on the structure of reduced graphs.
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Supported by NFSC of China under the Grant 61370071 and Fundamental Research Funds for the Central Universities under the Grant ZYGX2012J069
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Xiao, M., Nagamochi, H. An improved exact algorithm for undirected feedback vertex set. J Comb Optim 30, 214–241 (2015). https://doi.org/10.1007/s10878-014-9737-x
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DOI: https://doi.org/10.1007/s10878-014-9737-x