English

Inverse Lyndon words and Inverse Lyndon factorizations of words

Formal Languages and Automata Theory 2018-09-06 v7 Discrete Mathematics Data Structures and Algorithms

Abstract

Motivated by applications to string processing, we introduce variants of the Lyndon factorization called inverse Lyndon factorizations. Their factors, named inverse Lyndon words, are in a class that strictly contains anti-Lyndon words, that is Lyndon words with respect to the inverse lexicographic order. The Lyndon factorization of a nonempty word w is unique but w may have several inverse Lyndon factorizations. We prove that any nonempty word w admits a canonical inverse Lyndon factorization, named ICFL(w), that maintains the main properties of the Lyndon factorization of w: it can be computed in linear time, it is uniquely determined, it preserves a compatibility property for sorting suffixes. In particular, the compatibility property of ICFL(w) is a consequence of another result: any factor in ICFL(w) is a concatenation of consecutive factors of the Lyndon factorization of w with respect to the inverse lexicographic order.

Keywords

Cite

@article{arxiv.1705.10277,
  title  = {Inverse Lyndon words and Inverse Lyndon factorizations of words},
  author = {Paola Bonizzoni and Clelia De Felice and Rocco Zaccagnino and Rosalba Zizza},
  journal= {arXiv preprint arXiv:1705.10277},
  year   = {2018}
}