English
Related papers

Related papers: Algorithms for the Generation of Snarks

200 papers

We consider the problem of coloring the squares of graphs of bounded maximum average degree, that is, the problem of coloring the vertices while ensuring that two vertices that are adjacent or have a common neighbour receive different…

Discrete Mathematics · Computer Science 2013-08-21 Marthe Bonamy , Benjamin Lévêque , Alexandre Pinlou

Multi-layer graphs consist of several graphs (layers) over the same vertex set. They are motivated by real-world problems where entities (vertices) are associated via multiple types of relationships (edges in different layers). We chart the…

Computational Complexity · Computer Science 2019-10-23 Robert Bredereck , Christian Komusiewicz , Stefan Kratsch , Hendrik Molter , Rolf Niedermeier , Manuel Sorge

In the field of complex networks and graph theory, new results are typically tested on graphs generated by a variety of algorithms such as the Erd\H{o}s-R\'{e}nyi model or the Barab\'{a}si-Albert model. Unfortunately, most graph generating…

Combinatorics · Mathematics 2018-08-16 Isaac Klickstein , Francesco Sorrentino

In the Colored Clustering problem, one is asked to cluster edge-colored (hyper-)graphs whose colors represent interaction types. More specifically, the goal is to select as many edges as possible without choosing two edges that share an…

Data Structures and Algorithms · Computer Science 2023-02-02 Leon Kellerhals , Tomohiro Koana , Pascal Kunz , Rolf Niedermeier

We prove that every cyclically 4-edge-connected cubic graph that can be embedded in the projective plane, with the single exception of the Petersen graph, is 3-edge-colorable. In other words, the only (non-trivial) snark that can be…

Combinatorics · Mathematics 2024-05-28 Yuta Inoue , Ken-ichi Kawarabayashi , Atsuyuki Miyashita , Bojan Mohar , Tomohiro Sonobe

A brick is a 3-connected graph such that the graph obtained from it by deleting any two distinct vertices has a perfect matching. A brick is minimal if for every edge e the deletion of e results in a graph that is not a brick. We prove a…

Combinatorics · Mathematics 2019-07-02 Serguei Norine , Robin Thomas

Planar drawings of graphs tend to be favored over non-planar drawings. Testing planarity and creating a planar layout of a planar graph can be done in linear time. However, creating readable drawings of nearly planar graphs remains a…

Computational Geometry · Computer Science 2023-04-18 Simon van Wageningen , Tamara Mchedlidze , Alexandru Telea

A normal $k$-edge-coloring of a cubic graph is an edge-coloring with $k$ colors having the additional property that when looking at the set of colors assigned to any edge $e$ and the four edges adjacent it, we have either exactly five…

Discrete Mathematics · Computer Science 2021-10-05 Giuseppe Mazzuoccolo , Vahan Mkrtchyan

The Grundy number of a graph is the maximum number of colours used by the "First-Fit" greedy colouring algorithm over all vertex orderings. Given a vertex ordering $\sigma= v_1,\dots,v_n$, the "First-Fit" greedy colouring algorithm colours…

Discrete Mathematics · Computer Science 2024-04-03 Laurent Beaudou , Caroline Brosse , Oscar Defrain , Florent Foucaud , Aurélie Lagoutte , Vincent Limouzy , Lucas Pastor

We show that the following two problems are fixed-parameter tractable with parameter k: testing whether a connected n-vertex graph with m edges has a square root with at most n-1+k edges and testing whether such a graph has a square root…

Data Structures and Algorithms · Computer Science 2013-10-22 Manfred Cochefert , Jean-François Couturier , Petr A. Golovach , Dieter Kratsch , Daniël Paulusma

For many graph-related problems, it can be essential to have a set of structurally diverse graphs. For instance, such graphs can be used for testing graph algorithms or their neural approximations. However, to the best of our knowledge, the…

Machine Learning · Computer Science 2024-12-13 Fedor Velikonivtsev , Mikhail Mironov , Liudmila Prokhorenkova

A graph is called equimatchable if all of its maximal matchings have the same size. Frendrup et al. [8] provided a characterization of equimatchable graphs with girth at least $5$. In this paper, we extend this result by providing a…

Discrete Mathematics · Computer Science 2021-08-31 Yasemin Büyükçolak , Didem Gözüpek , Sibel Özkan

We give a (computer assisted) proof that the edges of every graph with maximum degree 3 and girth at least 17 may be 5-colored (possibly improperly) so that the complement of each color class is bipartite. Equivalently, every such graph…

Combinatorics · Mathematics 2009-10-23 Matt DeVos , Robert Samal

We introduce new sufficient conditions for intrinsic knotting and linking. A graph on n vertices with at least 4n-9 edges is intrinsically linked. A graph on n vertices with at least 5n-14 edges is intrinsically knotted. We also classify…

Geometric Topology · Mathematics 2007-05-23 J. Campbell , T. W. Mattman , R. Ottman , J. Pyzer , M. Rodrigues , S. Williams

Vertex coloring and multicoloring of graphs are a well known subject in graph theory, as well as their applications. In vertex multicoloring, each vertex is assigned some subset of a given set of colors. Here we propose a new kind of vertex…

Combinatorics · Mathematics 2018-09-13 Tanja Vojković , Damir Vukičević , Vinko Zlatić

Bounded expansion and nowhere-dense classes of graphs capture the theoretical tractability for several important algorithmic problems. These classes of graphs can be characterized by the so-called weak coloring numbers of graphs, which…

Data Structures and Algorithms · Computer Science 2022-09-27 Alexander Dobler , Manuel Sorge , Anaïs Villedieu

An edge-colored graph $G$ is said to be rainbow connected if between each pair of vertices there exists a path which uses each color at most once. The rainbow connection number, denoted by $rc(G)$, is the minimum number of colors needed to…

Discrete Mathematics · Computer Science 2015-10-14 Eduard Eiben , Robert Ganian , Juho Lauri

Graphs that are squares under the gluing algebra arise in the study of homomorphism density inequalities such as Sidorenko's conjecture. Recent work has focused on these homomorphism density applications. This paper takes a new perspective…

Combinatorics · Mathematics 2025-10-08 Karen L. Collins , David Galvin , Christine A. Kelley , Emily McMillon , Amanda Redlich

A fundamental algorithmic problem in computational biology is to find all subgraphs of a given type (superbubbles, snarls, and ultrabubbles) in a directed or bidirected input graph. These correspond to regions of genetic variation and are…

A graph is called $k$-critical if its chromatic number is $k$ but any proper subgraph has chromatic number less than $k$. An old and important problem in graph theory asks to determine the maximum number of edges in an $n$-vertex…

Combinatorics · Mathematics 2023-01-05 Cong Luo , Jie Ma , Tianchi Yang
‹ Prev 1 3 4 5 6 7 10 Next ›