Publication at Faculty of Mathematics and Physics |
2011
Abstract
We start a systematic parameterized computational complexity study of three NP-hard network design problems on arc-weighted directed graphs: Directed Steiner Tree, Strongly Connected Steiner Subgraph, and Directed Steiner Network. We investigate their parameterized complexities with respect to the three parameterizations: "number of terminals," "an upper bound on the size of the connecting network," and the combination of these two.
We achieve several parameterized hardness results as well as some fixed-parameter tractability results, in this way extending previous results of Feldman and Ruhl [SIAM J. Comput., 36 (2006), pp. 543-561].