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Related papers: Random Access to Grammar Compressed Strings

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We propose a simple and robust non-parameterized approach for building sentence representations. Inspired by the Gram-Schmidt Process in geometric theory, we build an orthogonal basis of the subspace spanned by a word and its surrounding…

Computation and Language · Computer Science 2019-12-09 Ziyi Yang , Chenguang Zhu , Weizhu Chen

The problem of storing a set of strings --- a string dictionary --- in compact form appears naturally in many cases. While classically it has represented a small part of the whole data to be processed (e.g., for Natural Language processing…

Data Structures and Algorithms · Computer Science 2011-01-31 Nieves R. Brisaboa , Rodrigo Cánovas , Miguel A. Martínez-Prieto , Gonzalo Navarro

This paper presents a new context-free parsing algorithm based on a bidirectional strictly horizontal strategy which incorporates strong top-down predictions (derivations and adjacencies). From a functional point of view, the parser is able…

cmp-lg · Computer Science 2007-05-23 Jose F. Quesada

Let $s$ be a string of length $n$ over an alphabet of constant size $\sigma$ and let $c$ and $\epsilon$ be constants with (1 \geq c \geq 0) and (\epsilon > 0). Using (O (n)) time, (O (n^c)) bits of memory and one pass we can always encode…

Information Theory · Computer Science 2007-08-15 Travis Gagie

A string $S[1,n]$ is a power (or tandem repeat) of order $k$ and period $n/k$ if it can decomposed into $k$ consecutive equal-length blocks of letters. Powers and periods are fundamental to string processing, and algorithms for their…

Data Structures and Algorithms · Computer Science 2018-05-28 Golnaz Badkobeh , Gabriele Fici , Simon J. Puglisi

In this paper we exploit concepts of information theory to address the fundamental problem of identifying and defining the most suitable tools to extract, in a automatic and agnostic way, information from a generic string of characters. We…

Statistical Mechanics · Physics 2009-11-10 Andrea Baronchelli , Emanuele Caglioti , Vittorio Loreto

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

The rank and select operations over a string of length n from an alphabet of size $\sigma$ have been used widely in the design of succinct data structures. In many applications, the string itself need be maintained dynamically, allowing…

Data Structures and Algorithms · Computer Science 2010-06-25 Meng He , J. Ian Munro

Countless variants of the Lempel-Ziv compression are widely used in many real-life applications. This paper is concerned with a natural modification of the classical pattern matching problem inspired by the popularity of such compression…

Data Structures and Algorithms · Computer Science 2011-04-22 Pawel Gawrychowski

In this paper we present an application of a simple technique of local recompression, previously developed by the author in the context of compressed membership problems and compressed pattern matching, to word equations. The technique is…

Formal Languages and Automata Theory · Computer Science 2014-03-19 Artur Jeż

The goal of grammar compression is to construct a small sized context free grammar which uniquely generates the input text data. Among grammar compression methods, RePair is known for its good practical compression performance. MR-RePair…

Data Structures and Algorithms · Computer Science 2019-10-31 Isamu Furuya

A compressed sensing method consists of a rectangular measurement matrix, $M \in \mathbbm{R}^{m \times N}$ with $m \ll N$, together with an associated recovery algorithm, $\mathcal{A}: \mathbbm{R}^m \rightarrow \mathbbm{R}^N$. Compressed…

Information Theory · Computer Science 2013-02-26 M. A. Iwen

We propose new succinct representations of ordinal trees, which have been studied extensively. It is known that any $n$-node static tree can be represented in $2n + o(n)$ bits and a number of operations on the tree can be supported in…

Data Structures and Algorithms · Computer Science 2010-09-27 Gonzalo Navarro , Kunihiko Sadakane

This paper presents a tree-to-tree transduction method for sentence compression. Our model is based on synchronous tree substitution grammar, a formalism that allows local distortion of the tree topology and can thus naturally capture…

Computation and Language · Computer Science 2014-01-23 Trevor Anthony Cohn , Mirella Lapata

Detecting all the strings that occur in a text more frequently or less frequently than expected according to an IID or a Markov model is a basic problem in string mining, yet current algorithms are based on data structures that are either…

Data Structures and Algorithms · Computer Science 2015-08-13 Djamal Belazzougui , Fabio Cunial

This paper is an extended abstract of an analysis of term rewriting where the terms in the rewrite rules as well as the term to be rewritten are compressed by a singleton tree grammar (STG). This form of compression is more general than…

Logic in Computer Science · Computer Science 2013-02-27 Manfred Schmidt-Schauss

It is shown that a context-free grammar of size $m$ that produces a single string $w$ (such a grammar is also called a string straight-line program) can be transformed in linear time into a context-free grammar for $w$ of size…

Data Structures and Algorithms · Computer Science 2020-07-02 Moses Ganardi , Artur Jeż , Markus Lohrey

The compact directed acyclic word graph (CDAWG) is the minimal compact automaton that recognizes all the suffixes of a string. Classically the CDAWG has been implemented as an index of the string it recognizes, requiring $o(n)$ space for a…

Data Structures and Algorithms · Computer Science 2024-07-15 Alan M. Cleary , Joseph Winjum , Jordan Dood , Shunsuke Inenaga

Prompt compression methods enhance the efficiency of Large Language Models (LLMs) and minimize the cost by reducing the length of input context. The goal of prompt compression is to shorten the LLM prompt while maintaining a high generation…

Computation and Language · Computer Science 2025-08-25 Tinghui Zhang , Yifan Wang , Daisy Zhe Wang

Term unification plays an important role in many areas of computer science, especially in those related to logic. The universal mechanism of grammar-based compression for terms, in particular the so-called Singleton Tree Grammars (STG),…

Logic in Computer Science · Computer Science 2010-03-13 Adrià Gascón , Guillem Godoy , Manfred Schmidt-Schauß