,
Yoàv Montacute
,
Kittiphon Phalakarn
,
Ichiro Hasuo
Creative Commons Attribution 4.0 International license
The Dijkstra algorithm is a classical method for solving the shortest path problem on weighted graphs. There are several variations of the Dijkstra algorithm, including algorithms for the widest path problem and for two-player games. In this paper, we introduce the coalgebraic shortest path problem (CSPP), a unifying framework for a broad class of optimization problems on state-transition systems. This framework encompasses not only the aforementioned problems but also new ones such as the shortest binary tree problem. We further present a coalgebraic Dijkstra algorithm for solving the CSPP efficiently under a suitable condition. Our condition is necessary and sufficient for the algorithm to return correct solutions, thereby providing a precise criterion for when Dijkstra-style acceleration is possible. We also show that the proposed algorithm achieves asymptotic complexity comparable to that of the classical Dijkstra algorithm.
@InProceedings{sanada_et_al:LIPIcs.CONCUR.2026.5,
author = {Sanada, Takahiro and Montacute, Yo\`{a}v and Phalakarn, Kittiphon and Hasuo, Ichiro},
title = {{A Coalgebraic Dijkstra Algorithm}},
booktitle = {37th International Conference on Concurrency Theory (CONCUR 2026)},
pages = {5:1--5:16},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-447-5},
ISSN = {1868-8969},
year = {2026},
volume = {391},
editor = {Sokolova, Ana and Totzke, Patrick},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CONCUR.2026.5},
URN = {urn:nbn:de:0030-drops-273365},
doi = {10.4230/LIPIcs.CONCUR.2026.5},
annote = {Keywords: Coalgebra, Greatest fixed point, Dijkstra’s algorithm, Shortest path}
}