• A Note on Exact Algorithms for Vertex Ordering Problems on Graphs 

      Bodlaender, Hans L.; Fomin, Fedor; Koster, Arie M.C.A.; Kratsch, Dieter; Thilikos, Dimitrios M. (Peer reviewed; Journal article, 2011-01-21)
      In this note, we give a proof that several vertex ordering problems can be solved in O ∗(2 n ) time and O ∗(2 n ) space, or in O ∗(4 n ) time and polynomial space. The algorithms generalize algorithms for the Travelling ...
    • Parameterized complexity of the spanning tree congestion problem 

      Bodlaender, Hans L.; Fomin, Fedor; Golovach, Petr; Otachi, Yota; van Leeuwen, Erik Jan (Peer reviewed; Journal article, 2012-09)
      We study the problem of determining the spanning tree congestion of a graph. We present some sharp contrasts in the parameterized complexity of this problem. First, we show that on apex-minor-free graphs, a general class ...
    • Treewidth is NP-Complete on Cubic Graphs 

      Bodlaender, Hans L.; Bonnet, Édouard; Jaffke, Lars; Knop, Dusan; Lima, Paloma Thome de; Milanič, Martin; Ordyniak, Sebastian; Pandey, Sukanya; Suchy, Ondrey (Journal article; Peer reviewed, 2023)
      In this paper, we show that Treewidth is NP-complete for cubic graphs, thereby improving the result by Bodlaender and Thilikos from 1997 that Treewidth is NP-complete on graphs with maximum degree at most 9. We add a new ...
    • Typical Sequences Revisited - Computing Width Parameters of Graphs 

      Bodlaender, Hans L.; Jaffke, Lars; Telle, Jan Arne (Journal article; Peer reviewed, 2021)
      In this work, we give a structural lemma on merges of typical sequences, a notion that was introduced in 1991 [Lagergren and Arnborg, Bodlaender and Kloks, both ICALP 1991] to obtain constructive linear time parameterized ...
    • Typical Sequences Revisited – Computing Width Parameters of Graphs 

      Bodlaender, Hans L.; Jaffke, Lars; Telle, Jan Arne (Journal article; Peer reviewed, 2020)
      In this work, we give a structural lemma on merges of typical sequences, a notion that was introduced in 1991 [Lagergren and Arnborg, Bodlaender and Kloks, both ICALP 1991] to obtain constructive linear time parameterized ...
    • XNLP-Completeness for Parameterized Problems on Graphs with a Linear Structure 

      Bodlaender, Hans L.; Groenland, Carla; Jacob, Hugo; Jaffke, Lars; Lima, Paloma Thome de (Journal article; Peer reviewed, 2022)
      In this paper, we showcase the class XNLP as a natural place for many hard problems parameterized by linear width measures. This strengthens existing W[1]-hardness proofs for these problems, since XNLP-hardness implies ...