License: Creative Commons Attribution 4.0 International license (CC BY 4.0)
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.ICDT.2021.12
URN: urn:nbn:de:0030-drops-137208
URL: http://dagstuhl.sunsite.rwth-aachen.de/volltexte/2021/13720/
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McGregor, Andrew ; Tench, David ; Vu, Hoa T.

Maximum Coverage in the Data Stream Model: Parameterized and Generalized

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LIPIcs-ICDT-2021-12.pdf (0.8 MB)


Abstract

We present algorithms for the Max Coverage and Max Unique Coverage problems in the data stream model. The input to both problems are m subsets of a universe of size n and a value k ∈ [m]. In Max Coverage, the problem is to find a collection of at most k sets such that the number of elements covered by at least one set is maximized. In Max Unique Coverage, the problem is to find a collection of at most k sets such that the number of elements covered by exactly one set is maximized. These problems are closely related to a range of graph problems including matching, partial vertex cover, and capacitated maximum cut. In the data stream model, we assume k is given and the sets are revealed online. Our goal is to design single-pass algorithms that use space that is sublinear in the input size. Our main algorithmic results are:
- If the sets have size at most d, there exist single-pass algorithms using O(d^{d+1} k^d) space that solve both problems exactly. This is optimal up to polylogarithmic factors for constant d.
- If each element appears in at most r sets, we present single pass algorithms using Õ(k² r/ε³) space that return a 1+ε approximation in the case of Max Coverage. We also present a single-pass algorithm using slightly more memory, i.e., Õ(k³ r/ε⁴) space, that 1+ε approximates Max Unique Coverage. In contrast to the above results, when d and r are arbitrary, any constant pass 1+ε approximation algorithm for either problem requires Ω(ε^{-2}m) space but a single pass O(ε^{-2}mk) space algorithm exists. In fact any constant-pass algorithm with an approximation better than e/(e-1) and e^{1-1/k} for Max Coverage and Max Unique Coverage respectively requires Ω(m/k²) space when d and r are unrestricted. En route, we also obtain an algorithm for a parameterized version of the streaming Set Cover problem.

BibTeX - Entry

@InProceedings{mcgregor_et_al:LIPIcs.ICDT.2021.12,
  author =	{McGregor, Andrew and Tench, David and Vu, Hoa T.},
  title =	{{Maximum Coverage in the Data Stream Model: Parameterized and Generalized}},
  booktitle =	{24th International Conference on Database Theory (ICDT 2021)},
  pages =	{12:1--12:20},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-179-5},
  ISSN =	{1868-8969},
  year =	{2021},
  volume =	{186},
  editor =	{Yi, Ke and Wei, Zhewei},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/opus/volltexte/2021/13720},
  URN =		{urn:nbn:de:0030-drops-137208},
  doi =		{10.4230/LIPIcs.ICDT.2021.12},
  annote =	{Keywords: Data streams, maximum coverage, maximum unique coverage, set cover}
}

Keywords: Data streams, maximum coverage, maximum unique coverage, set cover
Collection: 24th International Conference on Database Theory (ICDT 2021)
Issue Date: 2021
Date of publication: 11.03.2021


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