English
Related papers

Related papers: When a Dollar Makes a BWT

200 papers

In this paper we propose a flexible and lightweight technique for merging compressed indices based on variants of Burrows-Wheeler transform (BWT), thus addressing the need for algorithms that compute compressed indices over large…

Data Structures and Algorithms · Computer Science 2019-03-06 Lavinia Egidi , Giovanni Manzini

Highly-repetitive collections of strings are increasingly being amassed by genome sequencing and genetic variation experiments, as well as by storing all versions of human-generated files, like webpages and source code. Existing indexes for…

Data Structures and Algorithms · Computer Science 2016-04-22 Djamal Belazzougui , Fabio Cunial , Travis Gagie , Nicola Prezza , Mathieu Raffinot

The Lempel-Ziv factorization (LZ77) and the Run-Length encoded Burrows-Wheeler Transform (RLBWT) are two important tools in text compression and indexing, being their sizes $z$ and $r$ closely related to the amount of text…

Data Structures and Algorithms · Computer Science 2017-02-07 Alberto Policriti , Nicola Prezza

We prove that for every integer $n > 0$ and for every alphabet $\Sigma_k$ of size $k \geq 3$, there exists a necklace of length $n$ whose Burrows-Wheeler Transform (BWT) is completely unclustered, i.e., it consists of exactly $n$ runs with…

Discrete Mathematics · Computer Science 2025-08-29 Gabriele Fici , Estéban Gabory , Giuseppe Romana , Marinella Sciortino

We present an algorithm for building the extended BWT (eBWT) of a string collection from its grammar-compressed representation. Our technique exploits the string repetitions captured by the grammar to boost the computation of the eBWT.…

Genomics · Quantitative Biology 2021-02-10 Diego Diaz-Dominguez annd Gonzalo Navarro

In this paper we describe algorithms for computing the BWT and for building (compressed) indexes in external memory. The innovative feature of our algorithms is that they are lightweight in the sense that, for an input of size $n$, they use…

Data Structures and Algorithms · Computer Science 2009-09-25 Paolo Ferragina , Travis Gagie , Giovanni Manzini

Motivated by challenges in pangenomic read alignment, we propose a generalization of Wheeler graphs that we call Wheeler maps. A Wheeler map stores a text $T[1..n]$ and an assignment of tags to the characters of $T$ such that we can…

Data Structures and Algorithms · Computer Science 2023-08-22 Andrej Baláz , Travis Gagie , Adrián Goga , Simon Heumos , Gonzalo Navarro , Alessia Petescia , Jouni Sirén

The move structure represents permutations with long contiguously permuted intervals in compressed space with optimal query time. They have become an important feature of compressed text indexes using space proportional to the number of…

Data Structures and Algorithms · Computer Science 2026-04-28 Nathaniel K. Brown , Ben Langmead

Sublinear time quantum algorithms have been established for many fundamental problems on strings. This work demonstrates that new, faster quantum algorithms can be designed when the string is highly compressible. We focus on two popular and…

Data Structures and Algorithms · Computer Science 2023-02-15 Daniel Gibney , Sharma V. Thankachan

Some recent results have introduced external-memory algorithms to compute self-indexes of a set of strings, mainly via computing the Burrows-Wheeler Transform (BWT) of the input strings. The motivations for those results stem from…

Data Structures and Algorithms · Computer Science 2015-06-12 Paola Bonizzoni , Gianluca Della Vedova , Yuri Pirola , Marco Previtali , Raffaella Rizzi

Cartesian tree matching is a form of generalized pattern matching where a substring of the text matches with the pattern if they share the same Cartesian tree. This form of matching finds application for time series of stock prices and can…

Data Structures and Algorithms · Computer Science 2024-11-20 Eric M. Osterkamp , Dominik Köppl

Indexing very large collections of strings, such as those produced by the widespread next generation sequencing technologies, heavily relies on multistring generalization of the Burrows-Wheeler Transform (BWT): large requirements of…

Data Structures and Algorithms · Computer Science 2020-12-07 Paola Bonizzoni , Gianluca Della Vedova , Yuri Pirola , Marco Previtali , Raffaella Rizzi

We show how to build several data structures of central importance to string processing, taking as input the Burrows-Wheeler transform (BWT) and using small extra working space. Let $n$ be the text length and $\sigma$ be the alphabet size.…

Data Structures and Algorithms · Computer Science 2019-08-14 Nicola Prezza , Giovanna Rosone

The FM-index is a well-known compressed full-text index, based on the Burrows-Wheeler transform (BWT). During a pattern search, the BWT sequence is accessed at "random" locations, which is cache-unfriendly. In this paper, we are interested…

Data Structures and Algorithms · Computer Science 2015-12-08 Szymon Grabowski , Aleksander Cisłak

Prior work inspired by compression algorithms has described how the Burrows Wheeler Transform can be used to create a distance measure for bioinformatics problems. We describe issues with this approach that were not widely known, and…

Cryptography and Security · Computer Science 2020-02-19 Edward Raff , Charles Nicholas , Mark McLean

Ordering the collection of states of a given automaton starting from an order of the underlying alphabet is a natural move towards a computational treatment of the language accepted by the automaton. Along this path, Wheeler \emph{graphs}…

Formal Languages and Automata Theory · Computer Science 2021-06-14 Giovanna D'Agostino , Davide Martincigh , Alberto Policriti

Until recently, most experts would probably have agreed we cannot backwards-step in constant time with a run-length compressed Burrows-Wheeler Transform (RLBWT), since doing so relies on rank queries on sparse bitvectors and those inherit…

Data Structures and Algorithms · Computer Science 2022-07-15 Nathaniel K. Brown , Travis Gagie , Massimiliano Rossi

Compressed suffix arrays (CSAs) index large repetitive collections and are key in many text applications. The r-index and its derivatives combine the run-length Burrows-Wheeler Transform (BWT) with suffix array sampling to achieve space…

Data Structures and Algorithms · Computer Science 2026-02-20 Diego Díaz-Domínguez , Veli Mäkinen

The run-length compressed Burrows-Wheeler transform (RLBWT) used in conjunction with the backward search introduced in the FM index is the centerpiece of most compressed indexes working on highly-repetitive data sets like biological…

Data Structures and Algorithms · Computer Science 2021-10-05 Jin Jie Deng , Wing-Kai Hon , Dominik Köppl , Kunihiko Sadakane

In this paper, we consider the problem of compressing a trie while supporting the powerful \emph{locate} queries: to return the pre-order identifiers of all nodes reached by a path labeled with a given query pattern. Our result builds on…

Data Structures and Algorithms · Computer Science 2020-12-18 Nicola Prezza