2026-07-22T16:12:03Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:23057 2025-10-09T10:35:30Z ddc:004 open_access

On b-Matching and Fully-Dynamic Maximum k-Edge Coloring El-Hayek, Antoine Hanauer, Kathrin Henzinger, Monika dynamic algorithm graph algorithm matching b-matching edge coloring Given a graph G that undergoes a sequence of edge insertions and deletions, we study the Maximum k-Edge Coloring problem (MkEC): Having access to k different colors, color as many edges of G as possible such that no two adjacent edges share the same color. While this problem is different from simply maintaining a b-matching with b = k, the two problems are related. However, maximum b-matching can be solved efficiently in the static setting, whereas MkEC is NP-hard and even APX-hard for k ≥ 2. We present new results on both problems: For b-matching, we show a new integrality gap result and we adapt Wajc’s matching sparsification scheme [David Wajc, 2020] for the case where b is a constant. Using these as basis, we give three new algorithms for the dynamic MkEC problem: Our MatchO algorithm builds on the dynamic (2+ε)-approximation algorithm of Bhattacharya, Gupta, and Mohan [Sayan Bhattacharya et al., 2017] for b-matching and achieves a (2+ε)(k+1)/k-approximation in O(poly(log n, ε^-1)) update time against an oblivious adversary. Our MatchA algorithm builds on the dynamic (7+ε)-approximation algorithm by Bhattacharya, Henzinger, and Italiano [Sayan Bhattacharya et al., 2015] for fractional b-matching and achieves a (7+ε)(3k+3)/(3k-1)-approximation in O(poly(log n, ε^-1)) update time against an adaptive adversary. Moreover, our reductions use the dynamic b-matching algorithm as a black box, so any future improvement in the approximation ratio for dynamic b-matching will automatically translate into a better approximation ratio for our algorithms. Finally, we present a greedy algorithm with O(Δ+k) update time, which guarantees a 2.16 approximation factor. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Antoine El-Hayek and Kathrin Hanauer and Monika Henzinger 2025 Is Part Of LIPIcs, Volume 330, 4th Symposium on Algorithmic Foundations of Dynamic Networks (SAND 2025) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.SAND.2025.4 urn:nbn:de:0030-drops-230571 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SAND.2025.4 eng https://creativecommons.org/licenses/by/4.0/legalcode