,
Shay Golan
,
Shay Mozes
,
Daniel Prigan
,
Oren Weimann
Creative Commons Attribution 4.0 International license
We show how to preprocess a weighted undirected n-vertex planar graph in Õ(n^{4/3}) time, such that the distance between any pair of vertices can then be reported in Õ(1) time. This improves the previous Õ(n^{3/2}) preprocessing time [JACM'23].
Our main technical contribution is a near optimal construction of additively weighted Voronoi diagrams in undirected planar graphs. Namely, given a planar graph G and a face f, we show that one can preprocess G in Õ(n) time such that given any weight assignment to the vertices of f one can construct the additively weighted Voronoi diagram of f in near optimal Õ(|f|) time. This improves the Õ(√{n|f|}) construction time of [JACM'23].
@InProceedings{boneh_et_al:LIPIcs.ICALP.2025.33,
author = {Boneh, Itai and Golan, Shay and Mozes, Shay and Prigan, Daniel and Weimann, Oren},
title = {{Faster Construction of a Planar Distance Oracle with \~{O}(1) Query Time}},
booktitle = {52nd International Colloquium on Automata, Languages, and Programming (ICALP 2025)},
pages = {33:1--33:21},
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.2025.33},
URN = {urn:nbn:de:0030-drops-234106},
doi = {10.4230/LIPIcs.ICALP.2025.33},
annote = {Keywords: Distance Oracle, Planar Graph, Construction Time}
}