English
Related papers

Related papers: Edit Distance between Unrooted Trees in Cubic Time

200 papers

We present a near-linear time algorithm that approximates the edit distance between two strings within a polylogarithmic factor; specifically, for strings of length n and every fixed epsilon>0, it can compute a (log n)^O(1/epsilon)…

Data Structures and Algorithms · Computer Science 2010-05-24 Alexandr Andoni , Robert Krauthgamer , Krzysztof Onak

Many natural language processing (NLP) applications require the computation of similarities between pairs of syntactic or semantic trees. Many researchers have used tree edit distance for this task, but this technique suffers from the…

Computation and Language · Computer Science 2014-02-05 Maytham Alabbas , Allan Ramsay

The edit distance of two strings is the minimum number of insertions, deletions, and substitutions needed to transform one string into the other. The textbook algorithm determines the edit distance of length-$n$ strings in $O(n^2)$ time,…

Data Structures and Algorithms · Computer Science 2025-02-04 Egor Gorbachev , Tomasz Kociumaka

We give an algorithm that takes as input an $n$-vertex graph $G$ and an integer $k$, runs in time $2^{O(k^2)} n^{O(1)}$, and outputs a tree decomposition of $G$ of width at most $k$, if such a decomposition exists. This resolves the…

Data Structures and Algorithms · Computer Science 2023-08-21 Tuukka Korhonen , Daniel Lokshtanov

Metrics for merge trees that are simultaneously stable, informative, and efficiently computable have so far eluded researchers. We show in this work that it is possible to devise such a metric when restricting merge trees to ordered domains…

Information Retrieval · Computer Science 2022-12-06 Christopher J. Tralie , Zachary Schlamowitz , Jose Arbelo , Antonio I. Delgado , Charley Kirk , Nicholas A. Scoville

The early development of a zygote can be mathematically described by a developmental tree. To compare developmental trees of different species, we need to define distances on trees. If children cells after a division are not…

Combinatorics · Mathematics 2022-06-08 Yue Wang

Rotation distance between trees measures the number of simple operations it takes to transform one tree into another. There are no known polynomial-time algorithms for computing rotation distance. In the case of ordered rooted trees, we…

Data Structures and Algorithms · Computer Science 2018-03-19 Sean Cleary , Katherine St. John

We study the problem of estimating the edit distance between two $n$-character strings. While exact computation in the worst case is believed to require near-quadratic time, previous work showed that in certain regimes it is possible to…

Data Structures and Algorithms · Computer Science 2020-07-29 Joshua Brakensiek , Moses Charikar , Aviad Rubinstein

We present an algorithm for computing a maximum agreement subtree of two unrooted evolutionary trees. It takes O(n^{1.5} log n) time for trees with unbounded degrees, matching the best known time complexity for the rooted case. Our…

Computational Engineering, Finance, and Science · Computer Science 2007-05-23 Ming-Yang Kao , Tak-Wah Lam , Wing-Kin Sung , Hing-Fung Ting

We extend the theory of minimal absent words to (rooted and unrooted) trees, having edges labeled by letters from an alphabet $\Sigma$ of cardinality $\sigma$. We show that the set $\text{MAW}(T)$ of minimal absent words of a rooted (resp.…

Data Structures and Algorithms · Computer Science 2019-10-31 Gabriele Fici , Paweł Gawrychowski

Metric learning has the aim to improve classification accuracy by learning a distance measure which brings data points from the same class closer together and pushes data points from different classes further apart. Recent research has…

Machine Learning · Computer Science 2018-05-21 Benjamin Paaßen

We give practical, efficient algorithms that automatically determine the asymptotic distributed round complexity of a given locally checkable graph problem in the $[\Theta(\log n), \Theta(n)]$ region, in two settings. We present one…

Distributed, Parallel, and Cluster Computing · Computer Science 2022-09-05 Alkida Balliu , Sebastian Brandt , Yi-Jun Chang , Dennis Olivetti , Jan Studený , Jukka Suomela

The problem of approximate string matching is important in many different areas such as computational biology, text processing and pattern recognition. A great effort has been made to design efficient algorithms addressing several variants…

Data Structures and Algorithms · Computer Science 2008-07-29 Dimitris Papamichail , Georgios Papamichail

We study edit distance computation with preprocessing: the preprocessing algorithm acts on each string separately, and then the query algorithm takes as input the two preprocessed strings. This model is inspired by scenarios where we would…

Data Structures and Algorithms · Computer Science 2021-08-23 Elazar Goldenberg , Aviad Rubinstein , Barna Saha

The subtree prune-and-regraft (SPR) distance metric is a fundamental way of comparing evolutionary trees. It has wide-ranging applications, such as to study lateral genetic transfer, viral recombination, and Markov chain Monte Carlo…

Discrete Mathematics · Computer Science 2016-11-09 Chris Whidden , Frederick A. Matsen

A chief problem in phylogenetics and database theory is the computation of a maximum consistent tree from a set of rooted or unrooted trees. A standard input are triplets, rooted binary trees on three leaves, or quartets, unrooted binary…

Discrete Mathematics · Computer Science 2010-05-31 Leo van Iersel , Matthias Mnich

As well known the rotation distance D(S,T) between two binary trees S, T of n vertices is the minimum number of rotations of pairs of vertices to transform S into T. We introduce the new operation of chain rotation on a tree, involving two…

Data Structures and Algorithms · Computer Science 2012-04-27 Fabrizio Luccio , Linda Pagli

Almost 30 years ago, Zhang and Shasha (1989) published a seminal paper describing an efficient dynamic programming algorithm computing the tree edit distance, that is, the minimum number of node deletions, insertions, and replacements that…

Data Structures and Algorithms · Computer Science 2022-09-15 Benjamin Paaßen

In this paper, we design new sublinear-time algorithms for solving the gap edit distance problem and for embedding edit distance to Hamming distance. For the gap edit distance problem, we give an $\tilde{O}(\frac{n}{k}+k^2)$-time greedy…

Data Structures and Algorithms · Computer Science 2020-11-17 Tomasz Kociumaka , Barna Saha

Real-world data often comes in compressed form. Analyzing compressed data directly (without decompressing it) can save space and time by orders of magnitude. In this work, we focus on fundamental sequence comparison problems and try to…

Data Structures and Algorithms · Computer Science 2021-12-14 Arun Ganesh , Tomasz Kociumaka , Andrea Lincoln , Barna Saha