,
Anil Maheshwari
,
Sasanka Roy,
Michiel Smid,
Kasturi Varadarajan
Creative Commons Attribution 4.0 International license
In this work, we address the following question. Suppose we are given a set D of positive-weighted disks and a set T of n points in the plane, such that each point of T is contained in at least two disks of D. Then is there always a subset S of D such that the union of the disks in S contains all the points of T and the total weight of the disks of D that are not in S is at least a constant fraction of the total weight of the disks in D? In our work, we prove the Extraction Theorem that answers this question in the affirmative. Our constructive proof heavily exploits the geometry of disks, and in the process, we make interesting connections between our work and the literature on local search for geometric optimization problems. The Extraction Theorem helps to design the first polynomial-time O(1)-approximations for two important geometric covering problems involving disks.
@InProceedings{bandyapadhyay_et_al:LIPIcs.ITCS.2024.7,
author = {Bandyapadhyay, Sayan and Maheshwari, Anil and Roy, Sasanka and Smid, Michiel and Varadarajan, Kasturi},
title = {{Geometric Covering via Extraction Theorem}},
booktitle = {15th Innovations in Theoretical Computer Science Conference (ITCS 2024)},
pages = {7:1--7:20},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-309-6},
ISSN = {1868-8969},
year = {2024},
volume = {287},
editor = {Guruswami, Venkatesan},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITCS.2024.7},
URN = {urn:nbn:de:0030-drops-195355},
doi = {10.4230/LIPIcs.ITCS.2024.7},
annote = {Keywords: Covering, Extraction theorem, Double-disks, Submodularity, Local search}
}