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Related papers: Multicut Problems in Almost-Planar Graphs: The Dep…

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We show fixed-parameter tractability of the Directed Multicut problem with three terminal pairs (with a randomized algorithm). This problem, given a directed graph $G$, pairs of vertices (called terminals) $(s_1,t_1)$, $(s_2,t_2)$, and…

Data Structures and Algorithms · Computer Science 2024-01-11 Meike Hatzel , Lars Jaffke , Paloma T. Lima , Tomáš Masařík , Marcin Pilipczuk , Roohani Sharma , Manuel Sorge

A homomorphism from a graph $G$ to a graph $H$ is an edge-preserving mapping from $V(G)$ to $V(H)$. In the graph homomorphism problem, denoted by $Hom(H)$, the graph $H$ is fixed and we need to determine if there exists a homomorphism from…

Discrete Mathematics · Computer Science 2023-12-08 Carla Groenland , Isja Mannens , Jesper Nederlof , Marta Piecyk , Paweł Rzążewski

We investigate the terminal-pairability problem in the case when the base graph is a complete bipartite graph, and the demand graph is a (not necessarily bipartite) multigraph on the same vertex set. In computer science, this problem is…

Combinatorics · Mathematics 2020-04-22 Lucas Colucci , Péter L. Erdős , Ervin Győri , Tamás Róbert Mezei

Let $G$ be a graph on $n$ vertices and $\mathrm{STAB}_k(G)$ be the convex hull of characteristic vectors of its independent sets of size at most $k$. We study extension complexity of $\mathrm{STAB}_k(G)$ with respect to a fixed parameter…

Computational Complexity · Computer Science 2017-03-08 Jakub Gajarský , Petr Hliněný , Hans Raj Tiwary

For any particular class of graphs, algorithms for computational problems restricted to the class often rely on structural properties that depend on the specific problem at hand. This begs the question if a large set of such results can be…

We study the following general disjoint paths problem: given a supply graph $G$, a set $T\subseteq V(G)$ of terminals, a demand graph $H$ on the vertices $T$, and an integer $k$, the task is to find a set of $k$ pairwise vertex-disjoint…

Data Structures and Algorithms · Computer Science 2014-11-05 Dániel Marx , Paul Wollan

Beyond-planarity focuses on the study of geometric and topological graphs that are in some sense nearly-planar. Here, planarity is relaxed by allowing edge crossings, but only with respect to some local forbidden crossing configurations.…

Discrete Mathematics · Computer Science 2017-12-29 Patrizio Angelini , Michael A. Bekos , Michael Kaufmann , Maximilian Pfister , Torsten Ueckerdt

We study multi-budgeted variants of the classic minimum cut problem and graph separation problems that turned out to be important in parameterized complexity: Skew Multicut and Directed Feedback Arc Set. In our generalization, we assign…

Data Structures and Algorithms · Computer Science 2019-07-09 Stefan Kratsch , Shaohua Li , Dániel Marx , Marcin Pilipczuk , Magnus Wahlström

We show that the Minimal Length-Bounded L-But problem can be computed in linear time with respect to L and the tree-width of the input graph as parameters. In this problem the task is to find a set of edges of a graph such that after…

Data Structures and Algorithms · Computer Science 2016-10-25 Dušan Knop , Pavel Dvořák

We introduce a variant of the multiway cut that we call the min-max connected multiway cut. Given a graph $G=(V,E)$ and a set $\Gamma\subseteq V$ of $t$ terminals, partition $V$ into $t$ parts such that each part is connected and contains…

Data Structures and Algorithms · Computer Science 2026-05-05 Hans Raj Tiwary , Petr Kolman

MaxCut is a classical NP-complete problem and a crucial building block in many combinatorial algorithms. The famous Edwards-Erd\H{o}s bound states that any connected graph on n vertices with m edges contains a cut of size at least $m/2 +…

Data Structures and Algorithms · Computer Science 2024-07-02 Jonas Lill , Kalina Petrova , Simon Weber

We study the \emph{multiterminal cut} problem, which, given an $n$-vertex graph whose edges are integer-weighted and a set of terminals, asks for a partition of the vertex set such that each terminal is in a distinct part, and the total…

Data Structures and Algorithms · Computer Science 2017-11-20 Yixin Cao , Jianer Chen , Jia-Hao Fan

This paper revisits the classical Edge Disjoint Paths (EDP) problem, where one is given an undirected graph $G$ and a set of terminal pairs $P$ and asks whether $G$ contains a set of pairwise edge-disjoint paths connecting every terminal…

Data Structures and Algorithms · Computer Science 2018-08-13 Robert Ganian , Sebastian Ordyniak

We study the following Two-Sets Cut-Uncut problem on planar graphs. Therein, one is given an undirected planar graph $G$ and two sets of vertices $S$ and $T$. The question is, what is the minimum number of edges to remove from $G$, such…

Data Structures and Algorithms · Computer Science 2023-05-03 Matthias Bentert , Pål Grønås Drange , Fedor V. Fomin , Petr A. Golovach , Tuukka Korhonen

Given a list of k source-sink pairs in an edge-weighted graph G, the minimum multicut problem consists in selecting a set of edges of minimum total weight in G, such that removing these edges leaves no path from each source to its…

Data Structures and Algorithms · Computer Science 2017-09-18 Cédric Bentz

For a class $\mathcal{H}$ of graphs, #Sub$(\mathcal{H})$ is the counting problem that, given a graph $H\in \mathcal{H}$ and an arbitrary graph $G$, asks for the number of subgraphs of $G$ isomorphic to $H$. It is known that if $\mathcal{H}$…

Computational Complexity · Computer Science 2014-07-11 Radu Curticapean , Dániel Marx

We study the following version of cut sparsification. Given a large edge-weighted network $G$ with $k$ terminal vertices, compress it into a smaller network $H$ with the same terminals, such that every minimum terminal cut in $H$…

Data Structures and Algorithms · Computer Science 2019-10-08 Robert Krauthgamer , Havana , Rika

We prove that Multicut in directed graphs, parameterized by the size of the cutset, is W[1]-hard and hence unlikely to be fixed-parameter tractable even if restricted to instances with only four terminal pairs. This negative result almost…

Data Structures and Algorithms · Computer Science 2018-02-13 Marcin Pilipczuk , Magnus Wahlström

We investigate the parameterized complexity of finding subgraphs with hereditary properties on graphs belonging to a hereditary graph class. Given a graph $G$, a non-trivial hereditary property $\Pi$ and an integer parameter $k$, the…

Data Structures and Algorithms · Computer Science 2021-01-26 David Eppstein , Siddharth Gupta , Elham Havvaei

Given an edge-weighted directed graph $G=(V,E)$ on $n$ vertices and a set $T=\{t_1, t_2, \ldots, t_p\}$ of $p$ terminals, the objective of the \scss ($p$-SCSS) problem is to find an edge set $H\subseteq E$ of minimum weight such that $G[H]$…

Data Structures and Algorithms · Computer Science 2016-04-07 Rajesh Chitnis , Hossein Esfandiari , MohammadTaghi Hajiaghayi , Rohit Khandekar , Guy Kortsarz , Saeed Seddighin