,
David Saulpic
Creative Commons Attribution 4.0 International license
Clustering problems such as k-means and k-median are staples of unsupervised learning, and many algorithmic techniques have been developed to tackle their numerous aspects. In this paper, we focus on the class of greedy approximation algorithm, that attracted less attention than local-search or primal-dual counterparts. In particular, we study the recursive greedy algorithm developed by Mettu and Plaxton [SIAM J. Comp 2003]. We provide a simplification of the algorithm, allowing for faster implementation: our algorithm matches the state-of-the-art running time for computing a constant-factor approximation in Euclidean space and graph metrics, and, in addition, is the first near-linear-time to compute a polylogarithmic approximation in Euclidean space.
@InProceedings{duprelatour_et_al:LIPIcs.ICALP.2026.84,
author = {Dupr\'{e} la Tour, Max and Saulpic, David},
title = {{Faster and Simpler Greedy Algorithm for k-Median and k-Means}},
booktitle = {53rd International Colloquium on Automata, Languages, and Programming (ICALP 2026)},
pages = {84:1--84:16},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-428-4},
ISSN = {1868-8969},
year = {2026},
volume = {374},
editor = {Bhattacharya, Sayan and Nanongkai, Danupon and Benedikt, Michael 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.2026.84},
URN = {urn:nbn:de:0030-drops-264735},
doi = {10.4230/LIPIcs.ICALP.2026.84},
annote = {Keywords: Clustering, k-means, approximation algorithm}
}