Distributed weighted min-cut in nearly-optimal time
2021 (English)In: Proceedings of the Annual ACM Symposium on Theory of Computing, Association for Computing Machinery (ACM) , 2021, p. 1144-1153Conference paper, Published paper (Refereed)
Abstract [en]
Minimum-weight cut (min-cut) is a basic measure of a network’s connectivity strength. While the min-cut can be computed efficiently in the sequential setting [Karger STOC’96], there was no efficient way for a distributed network to compute its own min-cut without limiting the input structure or dropping the output quality: In the standard CONGEST model, existing algorithms with nearly-optimal time (e.g. [Ghaffari, Kuhn, DISC’13; Nanongkai, Su, DISC’14]) can guarantee a solution that is (1+є)-approximation at best while the exact Õ(n0.8D0.2 + n0.9)-time algorithm [Ghaffari, Nowicki, Thorup, SODA’20] works only on simple networks (no weights and no parallel edges). Throughout, n and D denote the network’s number of vertices and hop-diameter, respectively. For the weighted case, the best bound was Õ(n) [Daga, Henzinger, Nanongkai, Saranurak, STOC’19]. In this paper, we provide an exact Õ(√n + D)-time algorithm for computing min-cut on weighted networks. Our result improves even the previous algorithm that works only on simple networks. Its time complexity matches the known lower bound up to polylogarithmic factors. At the heart of our algorithm are a routing trick and two structural lemmas regarding the structure of a minimum cut of a graph. These two structural lemmas considerably strengthen and generalize the framework of Mukhopadhyay-Nanongkai [STOC’20] and can be of independent interest.
Place, publisher, year, edition, pages
Association for Computing Machinery (ACM) , 2021. p. 1144-1153
Series
Proceedings of the Annual ACM Symposium on Theory of Computing, ISSN 0737-8017
Keywords [en]
CONGEST model, Minimun-cut, Approximation algorithms, Computation theory, Distributed networks, Minimum weight, Output quality, Poly-logarithmic factors, Simple networks, Time algorithms, Time complexity, Weighted networks, Graph algorithms
National Category
Computer Sciences
Identifiers
URN: urn:nbn:se:kth:diva-307423DOI: 10.1145/3406325.3451020ISI: 000810492500101Scopus ID: 2-s2.0-85103031034OAI: oai:DiVA.org:kth-307423DiVA, id: diva2:1631892
Conference
53rd Annual ACM SIGACT Symposium on Theory of Computing, STOC 2021, Virtual/Online, 21-25 June 2021
Note
Part of proceedings ISBN 978-1-4503-8053-9
QC 20220125
QC 20220718
2022-01-252022-01-252022-07-18Bibliographically approved