Oriented Spanners

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Given a point set P in the Euclidean plane and a parameter t, we define an oriented t-spanner as an oriented subgraph of the complete bi-directed graph such that for every pair of points, the shortest cycle in G through those points is at most a factor t longer than the shortest oriented cycle in the complete bi-directed graph. We investigate the problem of computing sparse graphs with small oriented dilation. As we can show that minimising oriented dilation for a given number of edges is NP-hard in the plane, we first consider one-dimensional point sets. While obtaining a 1-spanner in this setting is straightforward, already for five points such a spanner has no plane embedding with the leftmost and rightmost point on the outer face. This leads to restricting to oriented graphs with a one-page book embedding on the one-dimensional point set. For this case we present a dynamic program to compute the graph of minimum oriented dilation that runs in O(n8) time for n points, and a greedy algorithm that computes a 5-spanner in O(n log n) time. Expanding these results finally gives us a result for two-dimensional point sets: we prove that for convex point sets the greedy triangulation results in an oriented O(1)-spanner.

Original languageEnglish
Title of host publication31st Annual European Symposium on Algorithms, ESA 2023
EditorsInge Li Gortz, Martin Farach-Colton, Simon J. Puglisi, Grzegorz Herman
PublisherSchloss Dagstuhl - Leibniz-Zentrum für Informatik
Publication date2023
Pages1-16
Article number26
ISBN (Electronic)9783959772952
DOIs
Publication statusPublished - 2023
Event31st Annual European Symposium on Algorithms, ESA 2023 - Amsterdam, Netherlands
Duration: 4 Sep 20236 Sep 2023

Conference

Conference31st Annual European Symposium on Algorithms, ESA 2023
LandNetherlands
ByAmsterdam
Periode04/09/202306/09/2023
SeriesLeibniz International Proceedings in Informatics, LIPIcs
Volume274
ISSN1868-8969

Bibliographical note

Publisher Copyright:
© Kevin Buchin, Joachim Gudmundsson, Antonia Kalb, Aleksandr Popov, Carolin Rehs, André van Renssen, and Sampson Wong.

    Research areas

  • computational geometry, greedy triangulation, oriented graph, spanner

ID: 382560406