81056 eng Moll, Lukas Tazari, Siamak Thurley, Marc Centre de Recerca Matemàtica Centre de Recerca Matemàtica 2011 Computing hypergraph width measures exactly 13 p. Hypergraph width measures are a class of hypergraph invariants important in studying the complexity of constraint satisfaction problems (CSPs). We present a general exact exponential algorithm for a large variety of these measures. A connection between these and tree decompositions is established. This enables us to almost seamlessly adapt the combinatorial and algorithmic results known for tree decompositions of graphs to the case of hypergraphs and obtain fast exact algorithms. As a consequence, we provide algorithms which, given a hypergraph H on n vertices and m hyperedges, compute the generalized hypertree-width of H in time O*(2n) and compute the fractional hypertree-width of H in time O(1.734601n.m).1 Aquest document està subjecte a una llicència d'ús de Creative Commons, amb la qual es permet copiar, distribuir i comunicar públicament l'obra sempre que se'n citin l'autor original, la universitat i el centre i no se'n faci cap ús comercial ni obra derivada, tal com queda estipulat en la llicència d'ús http://creativecommons.org/licenses/by-nc-nd/2.5/es/ 519.1 Hipergrafs Prepublicacions del Centre de Recerca Matemàtica ; 1033 http://ddd.uab.cat/pub/prepub/2011/hdl_2072_171357/Pr1033.pdf 258955 13 Adreça alternativa http://hdl.handle.net/2072/171357 PREPUB UAB hdl_2072_1177 oai:www.recercat.cat:2072/171357 info:eu-repo/semantics/preprint driver oai:ddd.uab.cat:81056