English
Related papers

Related papers: Conversion from RLBWT to LZ77

200 papers

In this paper we present a really simple linear-time algorithm constructing a context-free grammar of size O(g log (N/g)) for the input string, where N is the size of the input string and g the size of the optimal grammar generating this…

Data Structures and Algorithms · Computer Science 2014-03-19 Artur Jeż

Compression refers to encoding data using bits, so that the representation uses as few bits as possible. Compression could be lossless: i.e. encoded data can be recovered exactly from its representation) or lossy where the data is…

Information Theory · Computer Science 2012-10-19 Narayana Santhanam , Dharmendra Modha

The paper proposes an improved error-resilient Lempel-Ziv'77 (LZ'77) algorithm employing an adaptive amount of parity bits for error protection. It is a modified version of error resilient algorithm LZRS'77, proposed recently, which uses a…

Information Theory · Computer Science 2008-04-21 Tomaz Korosec , Saso Tomazic

Less than 1% of protein sequences are structurally and functionally annotated. Natural Language Processing (NLP) community has recently embraced self-supervised learning as a powerful approach to learn representations from unlabeled text,…

Biomolecules · Quantitative Biology 2020-12-08 Modestas Filipavicius , Matteo Manica , Joris Cadow , Maria Rodriguez Martinez

Compressed indexing enables powerful queries over massive and repetitive textual datasets using space proportional to the compressed input. While theoretical advances have led to highly efficient index structures, their practical…

Data Structures and Algorithms · Computer Science 2025-10-24 Ankith Reddy Adudodla , Dominik Kempa

LZ77-based compression schemes compress the input text by replacing factors in the text with an encoded reference to a previous occurrence formed by the couple (length, offset). For a given factor, the smallest is the offset, the smallest…

Data Structures and Algorithms · Computer Science 2012-11-22 Maxime Crochemore , Alessio Langiu , Filippo Mignosi

In this article we extend the elegant in-place Burrows-Wheeler transform (BWT) algorithm proposed by Crochemore et al. (Crochemore et al., 2015). Our extension is twofold: we first show how to compute simultaneously the longest common…

Data Structures and Algorithms · Computer Science 2018-06-08 Felipe A. Louza , Travis Gagie , Guilherme P. Telles

In this work, we study the limits of compressed data structures, i.e., structures that support various queries on an input text $T\in\Sigma^n$ using space proportional to the size of $T$ in compressed form. Nearly all fundamental queries…

Data Structures and Algorithms · Computer Science 2025-10-23 Dominik Kempa , Tomasz Kociumaka

The compressed indexing problem is to preprocess a string $S$ of length $n$ into a compressed representation that supports pattern matching queries. That is, given a string $P$ of length $m$ report all occurrences of $P$ in $S$. We present…

Data Structures and Algorithms · Computer Science 2018-04-12 Anders Roy Christiansen , Mikko Berggren Ettienne

We introduce the first self-index based on the Lempel-Ziv 1977 compression format (LZ77). It is particularly competitive for highly repetitive text collections such as sequence databases of genomes of related species, software repositories,…

Data Structures and Algorithms · Computer Science 2011-01-24 Sebastian Kreft , Gonzalo Navarro

The Burrows-Wheeler transform (BWT) is integral to the FM-index, which is used extensively in text compression, indexing, pattern search, and bioinformatic problems as de novo assembly and read alignment. Thus, efficient construction of the…

Data Structures and Algorithms · Computer Science 2025-02-04 Enno Adler , Stefan Böttcher , Rita Hartel , Cederic Alexander Steininger

An LZ-like factorization of a string divides it into factors, each being either a single character or a copy of a preceding substring. While grammar-based compression schemes support efficient random access with space linear in the…

Data Structures and Algorithms · Computer Science 2026-01-22 Hiroki Shibata , Yuto Nakashima , Yutaro Yamaguchi , Shunsuke Inenaga

State-of-the-art language models are becoming increasingly large in an effort to achieve the highest performance on large corpora of available textual data. However, the sheer size of the Transformer architectures makes it difficult to…

Machine Learning · Computer Science 2024-03-22 Tycho F. A. van der Ouderaa , Markus Nagel , Mart van Baalen , Yuki M. Asano , Tijmen Blankevoort

Fine-tuning large language models (LLMs) has achieved remarkable performance across various natural language processing tasks, yet it demands more and more memory as model sizes keep growing. To address this issue, the recently proposed…

Computation and Language · Computer Science 2024-12-04 Yifan Yang , Kai Zhen , Ershad Banijamal , Athanasios Mouchtaris , Zheng Zhang

Large language models (LLMs) have been applied in various applications due to their astonishing capabilities. With advancements in technologies such as chain-of-thought (CoT) prompting and in-context learning (ICL), the prompts fed to LLMs…

Computation and Language · Computer Science 2023-12-07 Huiqiang Jiang , Qianhui Wu , Chin-Yew Lin , Yuqing Yang , Lili Qiu

We explore a new language model inversion problem under strict black-box, zero-shot, and limited data conditions. We propose a novel training-free framework that reconstructs prompts using only a limited number of text outputs from a…

Computation and Language · Computer Science 2025-02-18 Hanqing Li , Diego Klabjan

We present an improved wavelet tree construction algorithm and discuss its applications to a number of rank/select problems for integer keys and strings. Given a string of length n over an alphabet of size $\sigma\leq n$, our method builds…

Data Structures and Algorithms · Computer Science 2015-05-18 Maxim Babenko , Paweł Gawrychowski , Tomasz Kociumaka , Tatiana Starikovskaya

We present ASPIRO, an approach for structured data verbalisation into short template sentences in zero to few-shot settings. Unlike previous methods, our approach prompts large language models (LLMs) to directly produce entity-agnostic…

Computation and Language · Computer Science 2023-10-30 Martin Vejvar , Yasutaka Fujimoto

Data compression is a powerful tool for managing massive but repetitive datasets, especially schemes such as grammar-based compression that support computation over the data without decompressing it. In the best case such a scheme takes a…

Data Structures and Algorithms · Computer Science 2019-06-04 Travis Gagie , Tomohiro I , Giovanni Manzini , Gonzalo Navarro , Hiroshi Sakamoto , Yoshimasa Takabatake

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