,
Simon Meierhans
,
Gernot Zöcklein
Creative Commons Attribution 4.0 International license
We give a simple algorithm for maintaining a n^{o(1)}-approximate spanner H of a graph G with n vertices as G receives edge updates by reduction to the dynamic All-Pairs Shortest Paths (APSP) problem. Given an initially empty graph G, our algorithm processes m insertions and n deletions in total time m^{1 + o(1)} and maintains an initially empty spanner H with total recourse n^{1 + o(1)}. When the number of insertions is much larger than the number of deletions, this notably yields recourse sub-linear in the total number of updates.
Our simple algorithm can be extended to maintain a δ ≥ ω(1)-approximate spanner with n^{1+o(1)} edges throughout a sequence of m insertions and D deletions with amortized update time n^{o(1)} and total recourse n^{1 + o(1)} + n^{o(1)} ⋅ D via batching.
@InProceedings{kyng_et_al:LIPIcs.ICALP.2025.111,
author = {Kyng, Rasmus and Meierhans, Simon and Z\"{o}cklein, Gernot},
title = {{A Simple Dynamic Spanner via APSP}},
booktitle = {52nd International Colloquium on Automata, Languages, and Programming (ICALP 2025)},
pages = {111:1--111:11},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-372-0},
ISSN = {1868-8969},
year = {2025},
volume = {334},
editor = {Censor-Hillel, Keren and Grandoni, Fabrizio and Ouaknine, Jo\"{e}l and Puppis, Gabriele},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICALP.2025.111},
URN = {urn:nbn:de:0030-drops-234886},
doi = {10.4230/LIPIcs.ICALP.2025.111},
annote = {Keywords: Dynamic graph algorithms, Spanner, Dynamic Greedy Spanner}
}