An FPT Algorithm for Directed Spanning k-Leaf

dc.creatorBonsma, Paul
dc.creatorDorn, Frederic
dc.date2007-11-26
dc.date.accessioned2026-07-07T08:45:00Z
dc.date.available2026-07-07T08:45:00Z
dc.descriptionAn out-branching of a directed graph is a rooted spanning tree with all arcs directed outwards from the root. We consider the problem of deciding whether a given directed graph D has an out-branching with at least k leaves (Directed Spanning k-Leaf). We prove that this problem is fixed parameter tractable, when k is chosen as the parameter. Previously this was only known for restricted classes of directed graphs. The main new ingredient in our approach is a lemma that shows that given a locally optimal out-branching of a directed graph in which every arc is part of at least one out-branching, either an out-branching with at least k leaves exists, or a path decomposition with width O(k^3) can be found. This enables a dynamic programming based algorithm of running time 2^{O(k^3 \log k)} n^{O(1)}, where n=|V(D)|.
dc.description17 pages, 8 figures
dc.identifierhttps://arxiv.org/abs/0711.4052
dc.identifierhttp://arxiv.org/abs/0711.4052
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/142854
dc.subjectData Structures and Algorithms
dc.subjectDiscrete Mathematics
dc.titleAn FPT Algorithm for Directed Spanning k-Leaf
dc.typetext

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