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Related papers: r*-indexing

200 papers

It is well known that ordinary persistence on graphs can be computed more efficiently than the general persistence. Recently, it has been shown that zigzag persistence on graphs also exhibits similar behavior. Motivated by these results, we…

Computational Geometry · Computer Science 2023-05-12 Tamal K. Dey , Tao Hou , Salman Parsa

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

We revisit the complexity of building, given a two-dimensional string of size $n$, an indexing structure that allows locating all $k$ occurrences of a two-dimensional pattern of size $m$. While a structure of size $\mathcal{O}(n)$ with…

Data Structures and Algorithms · Computer Science 2025-08-26 Paweł Gawrychowski , Adam Górkiewicz

Merging $T$ sorted, non-redundant lists containing $M$ elements into a single sorted, non-redundant result of size $N \ge M/T$ is a classic problem typically solved practically in $O(M \log T)$ time with a priority-queue data structure the…

Data Structures and Algorithms · Computer Science 2022-08-22 Gene Myers

Given a string $S$ of length $n$, the classic string indexing problem is to preprocess $S$ into a compact data structure that supports efficient subsequent pattern queries. In the \emph{deterministic} variant the goal is to solve the string…

Data Structures and Algorithms · Computer Science 2016-12-07 Philip Bille , Inge Li Gørtz , Frederik Rye Skjoldjensen

The convolution between a text string $S$ of length $N$ and a pattern string $P$ of length $m$ can be computed in $O(N \log m)$ time by FFT. It is known that various types of approximate string matching problems are reducible to…

Data Structures and Algorithms · Computer Science 2013-03-19 Toshiya Tanaka , Tomohiro I , Shunsuke Inenaga , Hideo Bannai , Masayuki Takeda

Strings in the real world are often encoded with some level of uncertainty. In the character-level uncertainty model, an uncertain string $X$ of length $n$ on an alphabet $\Sigma$ is a sequence of $n$ probability distributions over…

Data Structures and Algorithms · Computer Science 2024-03-22 Esteban Gabory , Chang Liu , Grigorios Loukides , Solon P. Pissis , Wiktor Zuba

A classic data structure problem is to preprocess a string T of length $n$ so that, given a query $q$, we can quickly find all substrings of T with Hamming distance at most $k$ from the query string. Variants of this problem have seen…

Data Structures and Algorithms · Computer Science 2026-04-03 Jackson Bibbens , Levi Borevitz , Samuel McCauley

Longest common extension queries (often called longest common prefix queries) constitute a fundamental building block in multiple string algorithms, for example computing runs and approximate pattern matching. We show that a sequence of $q$…

Data Structures and Algorithms · Computer Science 2016-04-08 Paweł Gawrychowski , Tomasz Kociumaka , Wojciech Rytter , Tomasz Waleń

In this paper we study the adaptive prefix coding problem in cases where the size of the input alphabet is large. We present an online prefix coding algorithm that uses $O(\sigma^{1 / \lambda + \epsilon}) $ bits of space for any constants…

Data Structures and Algorithms · Computer Science 2008-11-24 Travis Gagie , Marek Karpinski , Yakov Nekrich

A Longest Common Extension (LCE) query on a text $T$ of length $N$ asks for the length of the longest common prefix of suffixes starting at given two positions. We show that the signature encoding $\mathcal{G}$ of size $w = O(\min(z \log N…

Data Structures and Algorithms · Computer Science 2016-06-28 Takaaki Nishimoto , Tomohiro I , Shunsuke Inenaga , Hideo Bannai , Masayuki Takeda

In this paper we investigate the problem of partitioning an input string T in such a way that compressing individually its parts via a base-compressor C gets a compressed output that is shorter than applying C over the entire T at once.…

Data Structures and Algorithms · Computer Science 2009-06-26 Paolo Ferragina , Igor Nitto , Rossano Venturini

In the classic longest common substring (LCS) problem, we are given two strings $S$ and $T$, each of length at most $n$, over an alphabet of size $\sigma$, and we are asked to find a longest string occurring as a fragment of both $S$ and…

Data Structures and Algorithms · Computer Science 2025-11-18 Panagiotis Charalampopoulos , Tomasz Kociumaka , Jakub Radoszewski , Solon P. Pissis

We present a data structure that stores a sequence $s[1..n]$ over alphabet $[1..\sigma]$ in $n\Ho(s) + o(n)(\Ho(s){+}1)$ bits, where $\Ho(s)$ is the zero-order entropy of $s$. This structure supports the queries \access, \rank\ and \select,…

Data Structures and Algorithms · Computer Science 2012-04-03 Jeremy Barbay , Francisco Claude , Travis Gagie , Gonzalo Navarro , Yakov Nekrich

Traditional Insertion Sort runs in O(n^2) time because each insertion takes O(n) time. When people run Insertion Sort in the physical world, they leave gaps between items to accelerate insertions. Gaps help in computers as well. This paper…

Data Structures and Algorithms · Computer Science 2007-05-23 Michael A. Bender , Martin Farach-Colton , Miguel Mosteiro

In-place associative integer sorting technique was proposed for integer lists which requires only constant amount of additional memory replacing bucket sort, distribution counting sort and address calculation sort family of algorithms.…

Data Structures and Algorithms · Computer Science 2012-09-24 A. Emre Cetin

Let $\mathrm{SO}^{\mathit{plog}}$ denote the restriction of second-order logic, where second-order quantification ranges over relations of size at most poly-logarithmic in the size of the structure. In this article we investigate the…

Logic in Computer Science · Computer Science 2018-06-20 Flavio Ferrarotti , Senén González , Klaus-Dieter Schewe , José María Turull-Torres

The present letter proposes a modification in the well known Grover's search algorithm, which searches a database of $N$ unsorted items in $O(\sqrt{N/M})$ steps, where $M$ represents the number of solutions to the search problem.…

Quantum Physics · Physics 2014-07-11 A. S. Gupta , A. Pathak

We explore a new form of DFT, which we call the Polynomial Transform. It functions over finite fields, and a size $n$ transform takes $O(n)$ operations. In the multitape Turing machine model, it allows us to multiply two $n$ bit numbers in…

Data Structures and Algorithms · Computer Science 2019-12-11 Matt Groff

A self-index is a compressed data structure that supports locate queries -- reporting all positions where a given pattern occurs in a string while maintaining the string in compressed form. While many self-indexes have been proposed,…

Data Structures and Algorithms · Computer Science 2025-10-30 Takaaki Nishimoto , Yasuo Tabei