,
Jaegun Lee
,
Hee-Kap Ahn
Creative Commons Attribution 4.0 International license
Given a set of n points in d-dimensional space, each assigned a positive weight, we study the problem of finding k axis-parallel unit hypercubes that maximize the total weight of the points contained in their union. In this paper, we present both exact and (1 - ε)-approximation algorithms for the case of k = 2. We present an exact algorithm that runs in O(n²) time in the plane, improving the previous O(n² log² n)-time result. This algorithm generalizes to higher dimensions and larger k in O(n^{dk/2}) time for fixed d and k. We also present a (1 - ε)-approximation algorithm that runs in O(n log min{n, 1/ε} + 1/ε³) time for k = 2 in the plane, improving the best known result. Our approximation algorithm also extends to higher dimensions.
@InProceedings{chung_et_al:LIPIcs.ISAAC.2025.21,
author = {Chung, Chaeyoon and Lee, Jaegun and Ahn, Hee-Kap},
title = {{Covering Weighted Points Using Unit Squares}},
booktitle = {36th International Symposium on Algorithms and Computation (ISAAC 2025)},
pages = {21:1--21:14},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-408-6},
ISSN = {1868-8969},
year = {2025},
volume = {359},
editor = {Chen, Ho-Lin and Hon, Wing-Kai and Tsai, Meng-Tsung},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ISAAC.2025.21},
URN = {urn:nbn:de:0030-drops-249292},
doi = {10.4230/LIPIcs.ISAAC.2025.21},
annote = {Keywords: Maximum coverage, Unit squares, Approximation algorithms}
}