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Related papers: Approximating Edit Distance in Near-Linear Time

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For any $T \geq 1$, there are constants $R=R(T) \geq 1$ and $\zeta=\zeta(T)>0$ and a randomized algorithm that takes as input an integer $n$ and two strings $x,y$ of length at most $n$, and runs in time $O(n^{1+\frac{1}{T}})$ and outputs an…

Data Structures and Algorithms · Computer Science 2019-05-10 Michal Koucký , Michael E. Saks

We present a unified framework for accelerating edit-distance computation between two compressible strings using straight-line programs. For two strings of total length $N$ having straight-line program representations of total size $n$, we…

Computational Complexity · Computer Science 2009-02-17 Danny Hermelin , Gad M. Landau , Shir Landau , Oren Weimann

We present the first dynamic algorithms for Dyck and tree edit distances with subpolynomial update times. Dyck edit distance measures how far a parenthesis string is from a well-parenthesized expression, while tree edit distance quantifies…

Data Structures and Algorithms · Computer Science 2025-10-21 Debarati Das , Jacob Gilbert , MohammadTaghi Hajiaghayi , Tomasz Kociumaka , Barna Saha

We provide a deterministic algorithm that outputs an $O(n^{3/4} \log n)$-approximation for the Longest Common Subsequence (LCS) of two input sequences of length $n$ in near-linear time. This is the first deterministic approximation…

Data Structures and Algorithms · Computer Science 2025-07-31 Itai Boneh , Shay Golan , Matan Kraus

The tree edit distance is a natural dissimilarity measure between rooted ordered trees whose nodes are labeled over an alphabet $\Sigma$. It is defined as the minimum number of node edits (insertions, deletions, and relabelings) required to…

Data Structures and Algorithms · Computer Science 2025-07-04 Tomasz Kociumaka , Ali Shahali

We study approximation algorithms for variants of the \emph{median string} problem, which asks for a string that minimizes the sum of edit distances from a given set of $m$ strings of length $n$. Only the straightforward $2$-approximation…

Data Structures and Algorithms · Computer Science 2020-11-03 Diptarka Chakraborty , Debarati Das , Robert Krauthgamer

We study approximation algorithms for the following three string measures that are widely used in practice: edit distance (ED), longest common subsequence (LCS), and longest increasing sequence (LIS). All three problems can be solved…

Data Structures and Algorithms · Computer Science 2020-07-28 Kuan Cheng , Zhengzhong Jin , Xin Li , Yu Zheng

We study the classical approximate string matching problem, that is, given strings $P$ and $Q$ and an error threshold $k$, find all ending positions of substrings of $Q$ whose edit distance to $P$ is at most $k$. Let $P$ and $Q$ have…

Data Structures and Algorithms · Computer Science 2011-03-21 Philip Bille

We consider the problem of preprocessing two strings $S$ and $T$, of lengths $m$ and $n$, respectively, in order to be able to efficiently answer the following queries: Given positions $i,j$ in $S$ and positions $a,b$ in $T$, return the…

Data Structures and Algorithms · Computer Science 2021-03-08 Panagiotis Charalampopoulos , Paweł Gawrychowski , Shay Mozes , Oren Weimann

We present an algorithm for approximating the edit distance $\operatorname{ed}(x, y)$ between two strings $x$ and $y$ in time parameterized by the degree to which one of the strings $x$ satisfies a natural pseudorandomness property. The…

Data Structures and Algorithms · Computer Science 2018-11-13 William Kuszmaul

In this paper we are interested in indexing texts for substring matching queries with one edit error. That is, given a text $T$ of $n$ characters over an alphabet of size $\sigma$, we are asked to build a data structure that answers the…

Data Structures and Algorithms · Computer Science 2014-08-25 Djamal Belazzougui

The edit distance is a metric of dissimilarity between strings, widely applied in computational biology, speech recognition, and machine learning. Let $e_k(n)$ denote the average edit distance between random, independent strings of $n$…

Formal Languages and Automata Theory · Computer Science 2024-04-09 Gianfranco Bilardi , Michele Schimd

The Fr\'echet distance is a commonly used distance measure for curves. Computing the Fr\'echet distance between two polygonal curves of $n$ vertices takes roughly quadratic time, and conditional lower bounds suggest that approximating to…

Computational Geometry · Computer Science 2025-05-09 Thijs van der Horst , Marc van Kreveld , Tim Ophelders , Bettina Speckmann

We consider the approximate pattern matching problem under edit distance. In this problem we are given a pattern $P$ of length $w$ and a text $T$ of length $n$ over some alphabet $\Sigma$, and a positive integer $k$. The goal is to find all…

Data Structures and Algorithms · Computer Science 2018-11-06 Diptarka Chakraborty , Debarati Das , Michal Koucky

We give an $\tilde O(n^2)$ time algorithm for computing the exact Dynamic Time Warping distance between two strings whose run-length encoding is of size at most $n$. This matches (up to log factors) the known (conditional) lower bound, and…

Data Structures and Algorithms · Computer Science 2023-02-14 Itai Boneh , Shay Golan , Shay Mozes , Oren Weimann

The Fr\'echet distance is a commonly used similarity measure between curves. It is known how to compute the continuous Fr\'echet distance between two polylines with $m$ and $n$ vertices in $\mathbb{R}^d$ in $O(mn (\log \log n)^2)$ time;…

Computational Geometry · Computer Science 2022-08-29 Thijs van der Horst , Marc van Kreveld , Tim Ophelders , Bettina Speckmann

We give an algorithm that computes a $(1+\epsilon)$-approximate Steiner forest in near-linear time $n \cdot 2^{(1/\epsilon)^{O(ddim^2)} (\log \log n)^2}$. This is a dramatic improvement upon the best previous result due to Chan et al., who…

Computational Geometry · Computer Science 2019-04-09 Lee-Ad Gottlieb , Yair Bartal

The edit distance is a basic string similarity measure used in many applications such as text mining, signal processing, bioinformatics, and so on. However, the computational cost can be a problem when we repeat many distance calculations…

Data Structures and Algorithms · Computer Science 2017-01-24 Hiroyuki Hanada , Mineichi Kudo , Atsuyoshi Nakamura

One of the landmarks in approximation algorithms is the $O(\sqrt{\log n})$-approximation algorithm for the Uniform Sparsest Cut problem by Arora, Rao and Vazirani from 2004. The algorithm is based on a semidefinite program that finds an…

Data Structures and Algorithms · Computer Science 2016-07-05 Thomas Rothvoss

We introduce fast-decodable indexing schemes for edit distance which can be used to speed up edit distance computations to near-linear time if one of the strings is indexed by an indexing string $I$. In particular, for every length $n$ and…

Data Structures and Algorithms · Computer Science 2019-04-11 Bernhard Haeupler , Aviad Rubinstein , Amirbehshad Shahrasbi