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Related papers: Fast Longest Common Extensions in Small Space

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In this paper, we present the following results: (1) We propose a new \emph{dynamic compressed index} of $O(w)$ space, that supports searching for a pattern $P$ in the current text in $O(|P| f(M,w) + \log w \log |P| \log^* M (\log N + \log…

Data Structures and Algorithms · Computer Science 2016-04-07 Takaaki Nishimoto , I Tomohiro , Shunsuke Inenaga , Hideo Bannai , Masayuki Takeda

We consider the problem of encoding a string of length $n$ from an integer alphabet of size $\sigma$ so that access and substring equality queries (that is, determining the equality of any two substrings) can be answered efficiently. Any…

Data Structures and Algorithms · Computer Science 2020-05-12 Nicola Prezza

In this paper we consider the problem of computing the longest common abelian factor (LCAF) between two given strings. We present a simple $O(\sigma~ n^2)$ time algorithm, where $n$ is the length of the strings and $\sigma$ is the alphabet…

Data Structures and Algorithms · Computer Science 2015-03-03 Ali Alatabbi , Costas S. Iliopoulos , Alessio Langiu , M. Sohel Rahman

Indexing highly repetitive texts - such as genomic databases, software repositories and versioned text collections - has become an important problem since the turn of the millennium. A relevant compressibility measure for repetitive texts…

Data Structures and Algorithms · Computer Science 2020-12-17 Travis Gagie , Gonzalo Navarro , Nicola Prezza

Calculating the length of a longest common subsequence (LCS) of two strings $A$ and $B$ of length $n$ and $m$ is a classic research topic, with many worst-case oriented results known. We present two algorithms for LCS length calculation…

Data Structures and Algorithms · Computer Science 2014-05-22 Szymon Grabowski

In the longest common substring (LCS) problem, we are given two strings $S$ and $T$, each of length at most $n$, and we are asked to find a longest string occurring as a fragment of both $S$ and $T$. This is a classical and well-studied…

Data Structures and Algorithms · Computer Science 2018-07-17 Amihood Amir , Panagiotis Charalampopoulos , Solon P. Pissis , Jakub Radoszewski

Two recent lower bounds on the compressibility of repetitive sequences, $\delta \le \gamma$, have received much attention. It has been shown that a length-$n$ string $S$ over an alphabet of size $\sigma$ can be represented within the…

Data Structures and Algorithms · Computer Science 2023-11-10 Tomasz Kociumaka , Gonzalo Navarro , Francisco Olivares

The Longest Common Subsequence (LCS) is a fundamental string similarity measure, and computing the LCS of two strings is a classic algorithms question. A textbook dynamic programming algorithm gives an exact algorithm in quadratic time, and…

Data Structures and Algorithms · Computer Science 2023-02-13 Xiaoyu He , Ray Li

The problem of finding longest common subsequence (LCS) is one of the fundamental problems in computer science, which finds application in fields such as computational biology, text processing, information retrieval, data compression etc.…

Computational Complexity · Computer Science 2020-06-25 Amey Bhangale , Diptarka Chakraborty , Rajendra Kumar

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

In this paper, we present a new data structure called the packed compact trie (packed c-trie) which stores a set $S$ of $k$ strings of total length $n$ in $n \log\sigma + O(k \log n)$ bits of space and supports fast pattern matching queries…

Data Structures and Algorithms · Computer Science 2017-10-11 Takuya Takagi , Shunsuke Inenaga , Kunihiko Sadakane , Hiroki Arimura

We revisit the classic combinatorial pattern matching problem of finding a longest common subsequence (LCS). For strings $x$ and $y$ of length $n$, a textbook algorithm solves LCS in time $O(n^2)$, but although much effort has been spent,…

Computational Complexity · Computer Science 2018-03-05 Karl Bringmann , Marvin Künnemann

The Longest Common Subsequence (LCS) problem is a fundamental problem of sequence comparison. A natural approximation to this problem is a model in which every pairs of letters of two ``sequences'' are matched independently of the other…

Disordered Systems and Neural Networks · Physics 2016-08-31 J. Boutet de Monvel

Suffix arrays encode the lexicographical order of all suffixes of a text and are often combined with the Longest Common Prefix array (LCP) to simulate navigational queries on the suffix tree in reduced space. In space-critical applications…

Data Structures and Algorithms · Computer Science 2017-11-02 Nicola Prezza

In the Longest Common Factor with $k$ Mismatches (LCF$_k$) problem, we are given two strings $X$ and $Y$ of total length $n$, and we are asked to find a pair of maximal-length factors, one of $X$ and the other of $Y$, such that their…

We first review how we can store a run-length compressed suffix array (RLCSA) for a text $T$ of length $n$ over an alphabet of size $\sigma$ whose Burrows-Wheeler Transform (BWT) consists of $r$ runs in $O \left( \rule{0ex}{2ex} r \log (n /…

Data Structures and Algorithms · Computer Science 2025-04-22 Nathaniel K. Brown , Travis Gagie , Giovanni Manzini , Gonzalo Navarro , Marinella Sciortino

We present two structural results concerning longest common prefixes of non-empty languages. First, we show that the longest common prefix of the language generated by a context-free grammar of size $N$ equals the longest common prefix of…

Formal Languages and Automata Theory · Computer Science 2018-01-09 Michael Luttenberger , Raphaela Palenta , Helmut Seidl

Abelian string matching problems are becoming an object of considerable interest in last years. Very recently, Alatabbi et al. \cite{AILR2015} presented the first solution for the longest common Abelian factor problem for a pair of strings,…

Data Structures and Algorithms · Computer Science 2015-03-12 Szymon Grabowski

Suppose that we are given a string $s$ of length $n$ over an alphabet $\{0,1,\ldots,n^{O(1)}\}$ and $\delta$ is the string complexity of $s$, a known compression measure. We describe an index on $s$ with $O(\delta\log\frac{n}{\delta})$…

Data Structures and Algorithms · Computer Science 2026-04-15 Dmitry Kosolobov

The Longest Common Substring (LCS) and Longest Palindromic Substring (LPS) are classical problems in computer science, representing fundamental challenges in string processing. Both problems can be solved in linear time using a classical…

Data Structures and Algorithms · Computer Science 2023-09-06 Domenico Cantone , Simone Faro , Arianna Pavone , Caterina Viola