English
Related papers

Related papers: On the Complexity of BWT-runs Minimization via Alp…

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

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

In this paper we show how to use one or more assembled or partially assembled genome as the basis for a compressed full-text index of its readset. Specifically, we build a labelled tree by taking the assembled genome as a trunk and grafting…

Data Structures and Algorithms · Computer Science 2021-06-02 Travis Gagie , Garance Gourdel , Giovanni Manzini

The Burrows-Wheeler transform (BWT) is used by the bzip2 family of compressors. In this paper, we present a hardware architecture that implements an inplace algorithm to compute the BWT. Our design does not have explicit storage for the…

Signal Processing · Electrical Eng. & Systems 2022-09-07 Kleber Stangherlin , Andrew Kennings

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

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

In this paper we study the number $r_{bwt}$ of equal-letter runs produced by the Burrows-Wheeler transform ($BWT$) when it is applied to purely morphic finite words, which are words generated by iterating prolongable morphisms. Such a…

Formal Languages and Automata Theory · Computer Science 2022-02-08 Andrea Frosini , Ilaria Mancini , Simone Rinaldi , Giuseppe Romana , Marinella Sciortino

The sort transform (ST) is a modification of the Burrows-Wheeler transform (BWT). Both transformations map an arbitrary word of length n to a pair consisting of a word of length n and an index between 1 and n. The BWT sorts all rotation…

Data Structures and Algorithms · Computer Science 2009-08-04 Manfred Kufleitner

The recently introduced class of Wheeler graphs, inspired by the Burrows-Wheeler Transform (BWT) of a given string, admits an efficient index data structure for searching for subpaths with a given path label, and lifts the applicability of…

Formal Languages and Automata Theory · Computer Science 2020-02-25 Jarno Alanko , Giovanna D'Agostino , Alberto Policriti , Nicola Prezza

The Burrows Wheeler transform has applications in data compression as well as full text indexing. Despite its important applications and various existing algorithmic approaches the construction of the transform for large data sets is still…

Data Structures and Algorithms · Computer Science 2016-04-25 German Tischler

In this paper, we present the first study of the computational complexity of converting an automata-based text index structure, called the Compact Directed Acyclic Word Graph (CDAWG), of size $e$ for a text $T$ of length $n$ into other text…

Data Structures and Algorithms · Computer Science 2023-08-07 Hiroki Arimura , Shunsuke Inenaga , Yasuaki Kobayashi , Yuto Nakashima , Mizuki Sue

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

In recent years, the focus of bioinformatics research has moved from individual sequences to collections of sequences. Given the fundamental role of the Burrows-Wheeler Transform (BWT) in string processing, a number of dedicated tools have…

Data Structures and Algorithms · Computer Science 2025-05-28 Davide Cenzato , Zsuzsanna Lipták

A weight based dynamic compression method has recently been proposed, which is especially suitable for the encoding of files with locally skewed distributions. Its main idea is to assign larger weights to closer to be encoded symbols by…

Data Structures and Algorithms · Computer Science 2021-05-24 Aharon Fruchtman , Yoav Gross , Shmuel T. Klein , Dana Shapira

Enumerating characteristic substrings (e.g., maximal repeats, minimal unique substrings, and minimal absent words) in a given string has been an important research topic because there are a wide variety of applications in various areas such…

Data Structures and Algorithms · Computer Science 2021-03-03 Takaaki Nishimoto , Yasuo Tabei

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

Advances in DNA sequencing technology have stimulated the development of algorithms and tools for processing very large collections of short strings (reads). Short-read alignment and assembly are among the most well-studied problems. Many…

Genomics · Quantitative Biology 2014-01-30 Chi-Man Liu , Ruibang Luo , Tak-Wah Lam

In this paper, we show that the LZ77 factorization of a text T {\in\Sigma^n} can be computed in O(R log n) bits of working space and O(n log R) time, R being the number of runs in the Burrows-Wheeler transform of T reversed. For extremely…

Data Structures and Algorithms · Computer Science 2015-10-22 Nicola Prezza , Alberto Policriti

Text indexing is a classical algorithmic problem that has been studied for over four decades: given a text $T$, pre-process it off-line so that, later, we can quickly count and locate the occurrences of any string (the query pattern) in $T$…

Data Structures and Algorithms · Computer Science 2020-12-15 Nicola Prezza

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