English

Improved Distance Queries and Cycle Counting by Frobenius Normal Form

Data Structures and Algorithms 2023-03-14 v4

Abstract

Consider an unweighted, directed graph GG with the diameter DD. In this paper, we introduce the framework for counting cycles and walks of given length in matrix multiplication time O~(nω)\widetilde{O}(n^\omega). The framework is based on the fast decomposition into Frobenius normal form and the Hankel matrix-vector multiplication. It allows us to solve the All-Nodes Shortest Cycles, All-Pairs All Walks problems efficiently and also give some improvement upon distance queries in unweighted graphs.

Keywords

Cite

@article{arxiv.1611.03789,
  title  = {Improved Distance Queries and Cycle Counting by Frobenius Normal Form},
  author = {Piotr Sankowski and Karol Węgrzycki},
  journal= {arXiv preprint arXiv:1611.03789},
  year   = {2023}
}

Comments

Lemma 2 in the previous version of this paper is incorrect. We thank Adam Karczmarz for pointing out the mistake

R2 v1 2026-06-22T16:49:39.601Z