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Related papers: RLBWT Tricks

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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

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 revisit the problem of permuting an array of length $n$ according to a given permutation in place, that is, using only a small number of bits of extra storage. Fich, Munro and Poblete [FOCS 1990, SICOMP 1995] obtained an elegant…

Data Structures and Algorithms · Computer Science 2021-01-12 Bartłomiej Dudek , Paweł Gawrychowski , Karol Pokorski

We assume the permutation $\pi$ is given by an $n$-element array in which the $i$-th element denotes the value $\pi(i)$. Constructing its inverse in-place (i.e. using $O(\log{n})$ bits of additional memory) can be achieved in linear time…

Data Structures and Algorithms · Computer Science 2020-04-22 Grzegorz Guśpiel

The suffix tree is arguably the most fundamental data structure on strings: introduced by Weiner (SWAT 1973) and McCreight (JACM 1976), it allows solving a myriad of computational problems on strings in linear time. Motivated by its large…

Data Structures and Algorithms · Computer Science 2026-05-07 Ruben Becker , Davide Cenzato , Travis Gagie , Sung-Hwan Kim , Ragnar Groot Koerkamp , Giovanni Manzini , Nicola Prezza

In this paper, we describe a new type of match between a pattern and a text that aren't necessarily maximal in the query, but still contain useful matching information: locally maximal exact matches (LEMs). There are usually a large amount…

Data Structures and Algorithms · Computer Science 2025-05-22 Ahsan Sanaullah , Degui Zhi , Shaojie Zhang

Parameterized strings are a generalization of strings in that their characters are drawn from two different alphabets, where one is considered to be the alphabet of static characters and the other to be the alphabet of parameter characters.…

Data Structures and Algorithms · Computer Science 2022-09-01 Daiki Hashimoto , Diptarama Hendrian , Dominik Köppl , Ryo Yoshinaka , Ayumi Shinohara

Indexing of very large collections of strings such as those produced by the widespread sequencing technologies, heavily relies on multi-string generalizations of the Burrows-Wheeler Transform (BWT), and for this problem various in-memory…

Data Structures and Algorithms · Computer Science 2016-07-29 Paola Bonizzoni , Gianluca Della Vedova , Serena Nicosia , Marco Previtali , Raffaella Rizzi

We introduce SIRI, Scaling Iterative Reinforcement Learning with Interleaved Compression, a simple yet effective RL approach for Large Reasoning Models (LRMs) that enables more efficient and accurate reasoning. Existing studies have…

Machine Learning · Computer Science 2025-09-30 Haoming Wen , Yushi Bai , Juanzi Li , Jie Tang

The Burrows-Wheeler Transform (BWT) serves as the basis for many important sequence indexes. On very large datasets (e.g. genomic databases), classical BWT construction algorithms are often infeasible because they usually need to have the…

Data Structures and Algorithms · Computer Science 2025-09-24 Jannik Olbrich

The field of succinct data structures has flourished over the last 16 years. Starting from the compressed suffix array (CSA) by Grossi and Vitter (STOC 2000) and the FM-index by Ferragina and Manzini (FOCS 2000), a number of generalizations…

Data Structures and Algorithms · Computer Science 2016-09-22 Djamal Belazzougui , Fabio Cunial , Juha Kärkkäinen , Veli Mäkinen

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

One of the most well-known variants of the Burrows-Wheeler transform (BWT) [Burrows and Wheeler, 1994] is the bijective BWT (BBWT) [Gil and Scott, arXiv 2012], which applies the extended BWT (EBWT) [Mantaci et al., TCS 2007] to the multiset…

Data Structures and Algorithms · Computer Science 2020-04-28 Dominik Köppl , Daiki Hashimoto , Diptarama Hendrian , Ayumi Shinohara

Training very deep convolutional networks is challenging, requiring significant computational resources and time. Existing acceleration methods often depend on specific architectures or require network modifications. We introduce…

Computer Vision and Pattern Recognition · Computer Science 2024-12-25 Evgeny Hershkovitch Neiterman , Gil Ben-Artzi

We explore various techniques to compress a permutation $\pi$ over n integers, taking advantage of ordered subsequences in $\pi$, while supporting its application $\pi$(i) and the application of its inverse $\pi^{-1}(i)$ in small time. Our…

Data Structures and Algorithms · Computer Science 2009-02-09 Jérémy Barbay , Gonzalo Navarro

The successor and predecessor problem consists of obtaining the closest value in a set of integers, greater/smaller than a given value. This problem has interesting applications, like the intersection of inverted lists. It can be easily…

Data Structures and Algorithms · Computer Science 2020-02-27 Adrián Gómez-Brandón

Bitmap indexes must be compressed to reduce input/output costs and minimize CPU usage. To accelerate logical operations (AND, OR, XOR) over bitmaps, we use techniques based on run-length encoding (RLE), such as Word-Aligned Hybrid (WAH)…

Databases · Computer Science 2016-08-02 Daniel Lemire , Owen Kaser , Kamel Aouiche

In permutation inversion, we are given a permutation $\pi : [N] \rightarrow [N]$, and want to prepare some advice of size $S$, such that we can efficiently invert any image in time $T$. This is a fundamental cryptographic problem with…

Computational Complexity · Computer Science 2025-10-15 Akshima , Tyler Besselman , Kai-Min Chung , Siyao Guo , Tzu-Yi Yang

Random backpropagation (RBP) is a variant of the backpropagation algorithm for training neural networks, where the transpose of the forward matrices are replaced by fixed random matrices in the calculation of the weight updates. It is…

Machine Learning · Computer Science 2017-12-25 Pierre Baldi , Peter Sadowski , Zhiqin Lu

Text retrieval using learned sparse representations of queries and documents has, over the years, evolved into a highly effective approach to search. It is thanks to recent advances in approximate nearest neighbor search-with the emergence…

Information Retrieval · Computer Science 2026-02-06 Sebastian Bruch , Martino Fontana , Franco Maria Nardini , Cosimo Rulli , Rossano Venturini