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A graph $G$ is said to be a $(k,\ell)$-graph if its vertex set can be partitioned into $k$ independent sets and $\ell$ cliques. It is well established that the recognition problem for $(k,\ell)$-graphs is NP-complete whenever $k \geq 3$ or…

Discrete Mathematics · Computer Science 2025-10-21 Flavia Bonomo-Braberman , Min Chih Lin , Ignacio Maqueda

We present a deterministic O(n log log n) time algorithm for finding shortest cycles and minimum cuts in planar graphs. The algorithm improves the previously known fastest algorithm by Italiano et al. in STOC'11 by a factor of log n. This…

Data Structures and Algorithms · Computer Science 2016-08-14 Jakub Łącki , Piotr Sankowski

A gambler moves on the vertices $1, \ldots, n$ of a graph using the probability distribution $p_{1}, \ldots, p_{n}$. A cop pursues the gambler on the graph, only being able to move between adjacent vertices. What is the expected number of…

Discrete Mathematics · Computer Science 2017-01-09 Jesse Geneson

In this paper, we consider the problem of finding a cycle of length $2k$ (a $C_{2k}$) in an undirected graph $G$ with $n$ nodes and $m$ edges for constant $k\ge2$. A classic result by Bondy and Simonovits [J.Comb.Th.'74] implies that if $m…

Data Structures and Algorithms · Computer Science 2017-03-31 Søren Dahlgaard , Mathias Bæk Tejs Knudsen , Morten Stöckel

We provide a deterministic algorithm that finds, in $\epsilon^{-O(1)} n^2$ time, an $\epsilon$-regular Frieze-Kannan partition of a graph on $n$ vertices. The algorithm outputs an approximation of a given graph as a weighted sum of…

Combinatorics · Mathematics 2019-08-21 Jacob Fox , László Miklós Lovász , Yufei Zhao

In the k-mappability problem, we are given a string x of length n and integers m and k, and we are asked to count, for each length-m factor y of x, the number of other factors of length m of x that are at Hamming distance at most k from y.…

Data Structures and Algorithms · Computer Science 2017-05-12 Mai Alzamel , Panagiotis Charalampopoulos , Costas S. Iliopoulos , Solon P. Pissis , Jakub Radoszewski , Wing-Kin Sung

The previously fastest algorithm for deciding the existence of an independent cut had a runtime of $\mathcal{O}^*(1.4423^n)$, where $n$ is the order of the input graph. We improve this to $\mathcal{O}^*(1.4143^n)$. In fact, we prove a…

Data Structures and Algorithms · Computer Science 2025-05-22 Vsevolod Chernyshev , Johannes Rauch , Dieter Rautenbach , Liliia Redina

Given a set $P$ of $n$ points in the plane, the unit-disk graph $G(P)$ is a graph with $P$ as its vertex set such that two points of $P$ have an edge if their Euclidean distance is at most $1$. We consider the problem of computing a maximum…

Computational Geometry · Computer Science 2025-06-30 Anastasiia Tkachenko , Haitao Wang

We give algorithms with running time $2^{O({\sqrt{k}\log{k}})} \cdot n^{O(1)}$ for the following problems. Given an $n$-vertex unit disk graph $G$ and an integer $k$, decide whether $G$ contains (1) a path on exactly/at least $k$ vertices,…

Data Structures and Algorithms · Computer Science 2017-04-25 Fedor V. Fomin , Daniel Lokshtanov , Fahad Panolan , Saket Saurabh , Meirav Zehavi

We study the Hamilton cycle problem with input a random graph G=G(n,p) in two settings. In the first one, G is given to us in the form of randomly ordered adjacency lists while in the second one we are given the adjacency matrix of G. In…

Combinatorics · Mathematics 2021-11-30 Michael Anastos

We present streaming algorithms for the graph $k$-matching problem in both the insert-only and dynamic models. Our algorithms, with space complexity matching the best upper bounds, have optimal or near-optimal update time, significantly…

Data Structures and Algorithms · Computer Science 2023-10-18 Jianer Chen , Qin Huang , Iyad Kanj , Qian Li , Ge Xia

This paper presents an $O^{*}(1.42^{n})$ time algorithm for the Maximum Cut problem on split graphs, along with a subexponential time algorithm for its decision variant.

Data Structures and Algorithms · Computer Science 2024-06-03 Marko Lalovic

In the 4-path vertex cover problem, the input is an undirected graph $G$ and an integer $k$. The goal is to decide whether there is a set of vertices $S$ of size at most $k$ such that every path with 4 vertices in $G$ contains at least one…

Data Structures and Algorithms · Computer Science 2019-01-08 Dekel Tsur

In the Densest k-Subgraph problem, given a graph G and a parameter k, one needs to find a subgraph of G induced on k vertices that contains the largest number of edges. There is a significant gap between the best known upper and lower…

Data Structures and Algorithms · Computer Science 2010-01-19 Aditya Bhaskara , Moses Charikar , Eden Chlamtac , Uriel Feige , Aravindan Vijayaraghavan

We provide a sublinear bound on the cop throttling number of a connected graph. Related to the graph searching game Cops and Robbers, the cop throttling number, written $\mathrm{th}_c(G)$, is given by…

Combinatorics · Mathematics 2019-01-28 Anthony Bonato , Sean English

An algorithm is developed for finding a close to optimal junction tree of a given graph G. The algorithm has a worst case complexity O(c^k n^a) where a and c are constants, n is the number of vertices, and k is the size of the largest…

Data Structures and Algorithms · Computer Science 2013-02-18 Ann Becker , Dan Geiger

We present new, faster pseudopolynomial time algorithms for the $k$-Subset Sum problem, defined as follows: given a set $Z$ of $n$ positive integers and $k$ targets $t_1, \ldots, t_k$, determine whether there exist $k$ disjoint subsets…

Data Structures and Algorithms · Computer Science 2022-01-04 Antonis Antonopoulos , Aris Pagourtzis , Stavros Petsalakis , Manolis Vasilakis

The game of cops and robbers, played on a fixed graph $G$, is a two-player game, where the cop and the robber (the players) take turns in moving to adjacent vertices. The game finishes if the cop lands on the robber's vertex. In that case…

Combinatorics · Mathematics 2026-02-24 Jorge Cruz Chapital , Tomáš Flídr , Maria-Romina Ivan

In this paper, we study the game of cops and robber on the class of graphs with no even hole (induced cycle of even length) and claw (a star with three leaves). The cop number of a graph $G$ is defined as the minimum number of cops needed…

Combinatorics · Mathematics 2022-01-12 Ramin Javadi , Ali Momeni

Given an $n$-vertex $m$-edge graph $G$ with non negative edge-weights, the girth of $G$ is the weight of a shortest cycle in $G$. For any graph $G$ with polynomially bounded integer weights, we present a deterministic algorithm that…

Data Structures and Algorithms · Computer Science 2018-10-25 Guillaume Ducoffe