文章基本信息

标题：Abusing the Tutte Matrix: An Algebraic Instance Compression for the K-set-cycle Problem
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作者：Magnus Wahlstr{\"o}m
期刊名称：LIPIcs : Leibniz International Proceedings in Informatics
电子版ISSN：1868-8969
出版年度：2013
卷号：20
页码：341-352
DOI：10.4230/LIPIcs.STACS.2013.341
出版社：Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik
摘要：We give an algebraic, determinant-based algorithm for the K-Cycle problem, i.e., the problem of finding a cycle through a set of specified elements. Our approach gives a simple FPT algorithm for the problem, matching the O^*(2^|K|) running time of the algorithm of Björklund et al. (SODA, 2012). Furthermore, our approach is open for treatment by classical algebraic tools (e.g., Gaussian elimination), and we show that it leads to a polynomial compression of the problem, i.e., a polynomial-time reduction of the K-Cycle problem into an algebraic problem with coding size O(|K|^3). This is surprising, as several related problems (e.g., k-Cycle and the Disjoint Paths problem) are known not to admit such a reduction unless the polynomial hierarchy collapses. Furthermore, despite the result, we are not aware of any witness for the K-Cycle problem of size polynomial in |K|+ log n, which seems (for now) to separate the notions of polynomial compression and polynomial kernelization (as a polynomial kernelization for a problem in NP necessarily implies a small witness).
关键词：Parameterized complexity; graph theory; kernelization; algebraic algorithms