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oai:drops-oai.dagstuhl.de:18675 2024-03-06T11:02:25Z ddc:004 open_access

Incremental (1-ε)-Approximate Dynamic Matching in O(poly(1/ε)) Update Time Blikstad, Joakim Kiss, Peter Bipartite Matching Incremental Matching Dynamic Algorithms Approximation Algorithms EDCS In the dynamic approximate maximum bipartite matching problem we are given bipartite graph G undergoing updates and our goal is to maintain a matching of G which is large compared the maximum matching size μ(G). We define a dynamic matching algorithm to be α (respectively (α, β))-approximate if it maintains matching M such that at all times |M | ≥ μ(G) ⋅ α (respectively |M| ≥ μ(G) ⋅ α - β). We present the first deterministic (1-ε)-approximate dynamic matching algorithm with O(poly(ε^{-1})) amortized update time for graphs undergoing edge insertions. Previous solutions either required super-constant [Gupta FSTTCS'14, Bhattacharya-Kiss-Saranurak SODA'23] or exponential in 1/ε [Grandoni-Leonardi-Sankowski-Schwiegelshohn-Solomon SODA'19] update time. Our implementation is arguably simpler than the mentioned algorithms and its description is self contained. Moreover, we show that if we allow for additive (1, ε⋅n)-approximation our algorithm seamlessly extends to also handle vertex deletions, on top of edge insertions. This makes our algorithm one of the few small update time algorithms for (1-ε)-approximate dynamic matching allowing for updates both increasing and decreasing the maximum matching size of G in a fully dynamic manner. Our algorithm relies on the weighted variant of the celebrated Edge-Degree-Constrained-Subgraph (EDCS) datastructure introduced by [Bernstein-Stein ICALP'15]. As far as we are aware we introduce the first application of the weighted-EDCS for arbitrarily dense graphs. We also present a significantly simplified proof for the approximation ratio of weighed-EDCS as a matching sparsifier compared to [Bernstein-Stein], as well as simple descriptions of a fractional matching and fractional vertex cover defined on top of the EDCS. Considering the wide range of applications EDCS has found in settings such as streaming, sub-linear, stochastic and more we hope our techniques will be of independent research interest outside of the dynamic setting. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Joakim Blikstad and Peter Kiss 2023 Is Part Of LIPIcs, Volume 274, 31st Annual European Symposium on Algorithms (ESA 2023) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ESA.2023.22 urn:nbn:de:0030-drops-186756 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ESA.2023.22 eng https://creativecommons.org/licenses/by/4.0/legalcode