English

Parameterized and Approximation Algorithms for the Maximum Bimodal Subgraph Problem

Data Structures and Algorithms 2023-08-31 v1

Abstract

A vertex of a plane digraph is bimodal if all its incoming edges (and hence all its outgoing edges) are consecutive in the cyclic order around it. A plane digraph is bimodal if all its vertices are bimodal. Bimodality is at the heart of many types of graph layouts, such as upward drawings, level-planar drawings, and L-drawings. If the graph is not bimodal, the Maximum Bimodal Subgraph (MBS) problem asks for an embedding-preserving bimodal subgraph with the maximum number of edges. We initiate the study of the MBS problem from the parameterized complexity perspective with two main results: (i) we describe an FPT algorithm parameterized by the branchwidth (and hence by the treewidth) of the graph; (ii) we establish that MBS parameterized by the number of non-bimodal vertices admits a polynomial kernel. As the byproduct of these results, we obtain a subexponential FPT algorithm and an efficient polynomial-time approximation scheme for MBS.

Keywords

Cite

@article{arxiv.2308.15635,
  title  = {Parameterized and Approximation Algorithms for the Maximum Bimodal Subgraph Problem},
  author = {Walter Didimo and Fedor V. Fomin and Petr A. Golovach and Tanmay Inamdar and Stephen Kobourov and Marie Diana Sieper},
  journal= {arXiv preprint arXiv:2308.15635},
  year   = {2023}
}

Comments

Appears in the Proceedings of the 31st International Symposium on Graph Drawing and Network Visualization (GD 2023)

R2 v1 2026-06-28T12:07:51.220Z