,
James A. Liu,
Pedro Matias
Creative Commons Attribution 3.0 Unported license
We consider the NP-complete problem of tracking paths in a graph, first introduced by Banik et al. [Banik et al., 2017]. Given an undirected graph with a source s and a destination t, find the smallest subset of vertices whose intersection with any s-t path results in a unique sequence. In this paper, we show that this problem remains NP-complete when the graph is planar and we give a 4-approximation algorithm in this setting. We also show, via Courcelle’s theorem, that it can be solved in linear time for graphs of bounded-clique width, when its clique decomposition is given in advance.
@InProceedings{eppstein_et_al:LIPIcs.ISAAC.2019.54,
author = {Eppstein, David and Goodrich, Michael T. and Liu, James A. and Matias, Pedro},
title = {{Tracking Paths in Planar Graphs}},
booktitle = {30th International Symposium on Algorithms and Computation (ISAAC 2019)},
pages = {54:1--54:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-130-6},
ISSN = {1868-8969},
year = {2019},
volume = {149},
editor = {Lu, Pinyan and Zhang, Guochuan},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ISAAC.2019.54},
URN = {urn:nbn:de:0030-drops-115500},
doi = {10.4230/LIPIcs.ISAAC.2019.54},
annote = {Keywords: Approximation Algorithm, Courcelle’s Theorem, Clique-Width, Planar, 3-SAT, Graph Algorithms, NP-Hardness}
}