r-Indexing the eBWT
- Autori: Boucher C.; Cenzato D.; Liptak Z.; Rossi M.; Sciortino M.
- Anno di pubblicazione: 2021
- Tipologia: Contributo in atti di convegno pubblicato in volume
- OA Link: http://hdl.handle.net/10447/526397
Abstract
The extended Burrows Wheeler Transform (eBWT ) was introduced by Mantaci et al. [TCS 2007] to extend the definition of the BWT to a collection of strings. In our prior work [SPIRE 2021], we give a linear-time algorithm for the eBWT that preserves the fundamental property of the original definition (i.e., the independence from the input order). The algorithm combines a modification of the Suffix Array Induced Sorting (SAIS) algorithm [IEEE Trans Comput 2011] with Prefix Free Parsing [AMB 2019; JCB 2020]. In this paper, we show how this construction algorithm leads to r-indexing the eBWT, i.e., run-length encoded eBWT and SA samples of Gagie et al. [SODA 2018] can be constructed efficiently from the components of the PFP. Moreover, we show that finding maximal exact matches (MEMs) between a query string and the r-index of the eBWT can be efficiently supported.