English

On the number of MUSs crossing a position

Data Structures and Algorithms 2025-08-25 v1

Abstract

A string ww is said to be a minimal unique substring (MUS) of a string TT if ww occurs exactly once in TT, and any proper substring of ww occurs at least twice in TT. It is known that the number of MUSs in a string TT of length nn is at most nn, and that the set MUS(T)MUS(T) of all MUSs in TT can be computed in O(n)O(n) time [Ilie and Smyth, 2011]. Let MUS(T,i)MUS(T,i) denote the set of MUSs that contain a position ii in a string TT. In this short paper, we present matching Θ(n)\Theta(\sqrt{n}) upper and lower bounds for the number MUS(T,i)|MUS(T,i)| of MUSs containing a position ii in a string TT of length nn.

Keywords

Cite

@article{arxiv.2508.16092,
  title  = {On the number of MUSs crossing a position},
  author = {Hiroto Fujimaru and Takuya Mieno and Shunsuke Inenaga},
  journal= {arXiv preprint arXiv:2508.16092},
  year   = {2025}
}

Comments

Accepted for SPIRE 2025 (short paper)