@inproceedings{89ce88bdbf3e48afbfab10c5f3ee6f45,
title = "Set cover with delay – Clairvoyance is not required",
abstract = "In most online problems with delay, clairvoyance (i.e. knowing the future delay of a request upon its arrival) is required for polylogarithmic competitiveness. In this paper, we show that this is not the case for set cover with delay (SCD) – specifically, we present the first non-clairvoyant algorithm, which is O(log n log m)-competitive, where n is the number of elements and m is the number of sets. This matches the best known result for the classic online set cover (a special case of non-clairvoyant SCD). Moreover, clairvoyance does not allow for significant improvement – we present lower bounds of Ω(√log n) and Ω(√log m) for SCD which apply for the clairvoyant case. In addition, the competitiveness of our algorithm does not depend on the number of requests. Such a guarantee on the size of the universe alone was not previously known even for the clairvoyant case – the only previously-known algorithm (due to Carrasco et al.) is clairvoyant, with competitiveness that grows with the number of requests. For the special case of vertex cover with delay, we show a simpler, deterministic algorithm which is 3-competitive (and also non-clairvoyant).",
keywords = "Clairvoyant, Delay, Set Cover",
author = "Yossi Azar and Ashish Chiplunkar and Shay Kutten and Noam Touitou",
note = "Publisher Copyright: {\textcopyright} Yossi Azar, Ashish Chiplunkar, Shay Kutten, and Noam Touitou; 28th Annual European Symposium on Algorithms, ESA 2020 ; Conference date: 07-09-2020 Through 09-09-2020",
year = "2020",
month = aug,
day = "1",
doi = "10.4230/LIPIcs.ESA.2020.8",
language = "الإنجليزيّة",
series = "Leibniz International Proceedings in Informatics, LIPIcs",
publisher = "Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing",
editor = "Fabrizio Grandoni and Grzegorz Herman and Peter Sanders",
booktitle = "28th Annual European Symposium on Algorithms, ESA 2020",
address = "ألمانيا",
}