Algorithms for Computing Abelian Periods of Words
arXiv:1211.5389 · doi:10.1016/j.dam.2013.08.021
Abstract
Constantinescu and Ilie (Bulletin EATCS 89, 167--170, 2006) introduced the notion of an \emph{Abelian period} of a word. A word of length over an alphabet of size can have distinct Abelian periods. The Brute-Force algorithm computes all the Abelian periods of a word in time using space. We present an off-line algorithm based on a $\sel$ function having the same worst-case theoretical complexity as the Brute-Force one, but outperforming it in practice. We then present on-line algorithms that also enable to compute all the Abelian periods of all the prefixes of .
Accepted for publication in Discrete Applied Mathematics