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This paper studies algorithms for computing a Gomory-Hu tree, which is a classical data structure that compactly stores all minimum $s$-$t$ cuts of an undirected weighted graph. We consider two classes of algorithms: the original method by…

Data Structures and Algorithms · Computer Science 2026-02-25 Vladimir Kolmogorov

We present efficient algorithms for computing a maximum agreement forest (MAF) of a pair of multifurcating (nonbinary) rooted trees. Our algorithms match the running times of the currently best algorithms for the binary case. The size of an…

Data Structures and Algorithms · Computer Science 2013-05-03 Chris Whidden , Robert G. Beiko , Norbert Zeh

Assume that an $N$-bit sequence $S$ of $k$ numbers encoded as Elias gamma codes is given as input. We present space-efficient algorithms for sorting, dense ranking and competitive ranking on $S$ in the word RAM model with word size…

Data Structures and Algorithms · Computer Science 2024-09-04 Frank Kammer , Johannes Meintrup , Andrej Sajenko

We consider the task of learning Ising models when the signs of different random variables are flipped independently with possibly unequal, unknown probabilities. In this paper, we focus on the problem of robust estimation of…

Machine Learning · Statistics 2020-06-11 Ashish Katiyar , Vatsal Shah , Constantine Caramanis

We give an algorithm to enumerate the results on trees of monadic second-order (MSO) queries represented by nondeterministic tree automata. After linear time preprocessing (in the input tree), we can enumerate answers with linear delay (in…

Databases · Computer Science 2019-08-28 Antoine Amarilli , Pierre Bourhis , Stefan Mengel , Matthias Niewerth

We initiate the study of tree structures in the context of scenario-based robust optimization. Specifically, we study Binary Search Trees (BSTs) and Huffman coding, two fundamental techniques for efficiently managing and encoding data based…

Data Structures and Algorithms · Computer Science 2024-08-22 Spyros Angelopoulos , Christoph Dürr , Alex Elenter , Georgii Melidi

Fast exact algorithms are known for Hamiltonian paths in undirected and directed bipartite graphs through elegant though involved algorithms that are quite different from each other. We devise algorithms that are simple and similar to each…

Data Structures and Algorithms · Computer Science 2025-12-10 V. Arvind , Srijan Chakraborty , Samir Datta , Asif Khan

The Gomory-Hu tree or cut tree (Gomory and Hu, 1961) is a classic data structure for reporting $(s,t)$ mincuts (and by duality, the values of $(s,t)$ maxflows) for all pairs of vertices $s$ and $t$ in an undirected graph. Gomory and Hu…

Data Structures and Algorithms · Computer Science 2021-11-04 Jason Li , Debmalya Panigrahi

We suggest a new non-recursive algorithm for constructing a binary search tree given an array of numbers. The algorithm has $O(N)$ time and $O(1)$ memory complexity if the given array of $N$ numbers is sorted. The resulting tree is of…

Data Structures and Algorithms · Computer Science 2022-07-20 Pavel S. Ruzankin

We present new and improved fixed-parameter algorithms for computing maximum agreement forests (MAFs) of pairs of rooted binary phylogenetic trees. The size of such a forest for two trees corresponds to their subtree prune-and-regraft…

Populations and Evolution · Quantitative Biology 2015-03-19 Chris Whidden , Robert G. Beiko , Norbert Zeh

In this paper, we present fixed-parameter tractability algorithms for both the undirected and directed versions of the Spanning Tree Isomorphism Problem, parameterized by the size $k$ of a redundant set. A redundant set is a collection of…

Data Structures and Algorithms · Computer Science 2025-08-08 Fangjian Shen , Yicheng Zheng , Wushao Wen , Hankz Hankui Zhuo

Linear tree constraints were introduced by Hofmann and Rodriguez in the context of amortized resource analysis for object oriented programs. More precisely, they gave a reduction from inference of resource types to constraint solving. Thus,…

Logic in Computer Science · Computer Science 2018-06-27 Sabine Bauer , Martin Hofmann

We present an axiomatic framework for analyzing the algorithmic properties of decision trees. This framework supports the classification of decision tree problems through structural and ancestral constraints within a rigorous mathematical…

Machine Learning · Computer Science 2025-10-24 Xi He , Max A. Little

This note presents an encoding and a decoding algorithms for a forest of (labelled) rooted uniform hypertrees and hypercycles in linear time, by using as few as $n - 2$ integers in the range $[1,n]$. It is a simple extension of the…

Discrete Mathematics · Computer Science 2011-10-04 Christian Lavault

It is an open question whether there exists a polynomial-time algorithm for computing the rotation distances between pairs of extended ordered binary trees. The problem of computing the rotation distance between an arbitrary pair of trees,…

Data Structures and Algorithms · Computer Science 2020-01-20 Sean Cleary , Roland Maio

Pairwise ordered tree alignment are combinatorial objects that appear in RNA secondary structure comparison. However, the usual representation of tree alignments as supertrees is ambiguous, i.e. two distinct supertrees may induce identical…

Quantitative Methods · Quantitative Biology 2016-03-08 Cedric Chauve , Julien Courtiel , Yann Ponty

Binary jumbled pattern matching asks to preprocess a binary string $S$ in order to answer queries $(i,j)$ which ask for a substring of $S$ that is of length $i$ and has exactly $j$ 1-bits. This problem naturally generalizes to…

Data Structures and Algorithms · Computer Science 2014-07-01 Travis Gagie , Danny Hermelin , Gad M. Landau , Oren Weimann

The study of optimal decision trees has gained increasing attention in recent years; however, despite substantial progress, it still suffers from two major challenges: First, trees constructed by existing optimal decision tree (ODT)…

Machine Learning · Computer Science 2026-05-04 Xi He

The sorting problem is one of the most relevant problems in computer science. Within the scope of modern computer science it has been studied for more than 70 years. In spite of these facts, new sorting algorithms have been developed in…

Data Structures and Algorithms · Computer Science 2014-11-04 Luis A. A. Meira , Rogério H. B. de Lima

Recently Kubica et al. (Inf. Process. Let., 2013) and Kim et al. (submitted to Theor. Comp. Sci.) introduced order-preserving pattern matching. In this problem we are looking for consecutive substrings of the text that have the same "shape"…