Talks and Poster Presentations (with Proceedings-Entry):

E. Eiben, R. Ganian, K. Kangas, S. Ordyniak:
"Counting Linear Extensions Parameterizations by Treewidth";
Talk: ESA Workshop, Aarhus, Denmark; 2016-08-22 - 2016-08-24; in: "Proceedings of the 24th Annual European Symposium on Algorithms", (2016), ISBN: 978-3-95977-015-6; 1 - 18.

English abstract:
We consider the #P-complete problem of counting the number of linear extensions of a poset (#LE); a fundamental problem in order theory with applications in a variety of distinct areas. In particular, we study the complexity of #LE parameterized by the well-known decompositional parameter treewidth for two natural graphical representations of the input poset, i.e., the cover and the incomparability graph. Our main result shows that #LE is fixed-parameter intractable parameterized by the treewidth of the cover graph. This resolves an open problem recently posed in the Dagstuhl seminar on Exact Algorithms. On the positive side we show that #LE becomes fixed-parameter tractable parameterized by the treewidth of the incomparability graph.

Electronic version of the publication:

Created from the Publication Database of the Vienna University of Technology.