Abstract
We prove that given a graph, one can efficiently find a set of no more than m/5.217 + 1 nodes whose removal yields a partial two-tree. As an application, we immediately get simple algorithms for several problems, including Max-Cut, Max-2-SAT and Max-2-XSAT. All of these take a record-breaking time of O *(2m/5.217), where m is the number of clauses or edges, while only using polynomial space. Moreover, the existence of the aforementioned node sets implies an upper bound of m/5.217 + 3 on the treewidth of a graph with m edges. Letting go of polynomial space restrictions, this can be improved to a bound of m/5.769 + O(log n) on the pathwidth, leading to algorithms for the above problems that take O *(2m/5.769) time.
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Kneis, J., Mölle, D., Richter, S., Rossmanith, P. (2005). Algorithms Based on the Treewidth of Sparse Graphs. In: Kratsch, D. (eds) Graph-Theoretic Concepts in Computer Science. WG 2005. Lecture Notes in Computer Science, vol 3787. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11604686_34
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DOI: https://doi.org/10.1007/11604686_34
Publisher Name: Springer, Berlin, Heidelberg
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