,
Bart M. P. Jansen
,
Jaime Venne
Creative Commons Attribution 4.0 International license
For a positive real γ ≥ 1, a γ-certified algorithm for a vertex-weighted graph optimization problem is an algorithm that, given a weighted graph (G,w), outputs a re-weighting of the graph obtained by scaling each weight individually with a factor between 1 and γ, along with a solution which is optimal for the perturbed weight function. Here we provide (1+ε)-certified algorithms for Dominating Set and H-Subgraph-Free-Deletion which, for any ε > 0, run in time f(1/ε)⋅n^𝒪(1) on minor-closed classes of graphs of bounded local tree-width with polynomially-bounded weights. We obtain our algorithms as corollaries of a more general result establishing FPT-time certified algorithms for problems admitting, at an intuitive level, certain "local solution-improvement properties". These results improve - in terms of generality, running time and parameter dependence - on Angelidakis, Awasthi, Blum, Chatziafratis and Dan’s XP-time (1+ε)-certified algorithm for Independent Set on planar graphs (ESA2019). Furthermore, our methods are also conceptually simpler: our algorithm is based on elementary local re-optimizations inspired by Baker’s technique, as opposed to the heavy machinery of the Sherali-Adams hierarchy required in previous work.
@InProceedings{bumpus_et_al:LIPIcs.SWAT.2024.19,
author = {Bumpus, Benjamin Merlin and Jansen, Bart M. P. and Venne, Jaime},
title = {{Fixed-Parameter Tractable Certified Algorithms for Covering and Dominating in Planar Graphs and Beyond}},
booktitle = {19th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT 2024)},
pages = {19:1--19:16},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-318-8},
ISSN = {1868-8969},
year = {2024},
volume = {294},
editor = {Bodlaender, Hans L.},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SWAT.2024.19},
URN = {urn:nbn:de:0030-drops-200595},
doi = {10.4230/LIPIcs.SWAT.2024.19},
annote = {Keywords: fixed-parameter tractability, certified algorithms}
}