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In an undirected graph, a conflict-free coloring (with respect to open neighborhoods) is an assignment of colors to the vertices of the graph $G$ such that every vertex in $G$ has a uniquely colored vertex in its open neighborhood. The…

Discrete Mathematics · Computer Science 2019-10-03 Sriram Bhyravarapu , Subrahmanyam Kalyanasundaram

Color-constrained subgraph problems are those where we are given an edge-colored (directed or undirected) graph and the task is to find a specific type of subgraph, like a spanning tree, an arborescence, a single-source shortest path tree,…

Data Structures and Algorithms · Computer Science 2024-07-24 P. S. Ardra , Jasine Babu , Kritika Kashyap , R. Krithika , Sreejith K. Pallathumadam , Deepak Rajendraprasad

DP-coloring (also known as correspondence coloring) is a generalization of list coloring developed recently by Dvorak and Postle. We introduce and study $(i,j)$-defective DP-colorings of multigraphs. We concentrate on sparse multigraphs and…

Combinatorics · Mathematics 2019-12-10 Yifan Jing , Alexandr Kostochka , Fuhong Ma , Pongpat Sittitrai , Jingwei Xu

We present a unified framework on the limits of constraint satisfaction problems (CSPs) and efficient parameter testing which depends only on array exchangeability and the method of cut decomposition without recourse to the weakly regular…

Data Structures and Algorithms · Computer Science 2016-08-05 Marek Karpinski , Roland Markó

The problem of finding the minimum number of colors to color a graph properly without containing any bicolored copy of a fixed family of subgraphs has been widely studied. Most well-known examples are star coloring and acyclic coloring of…

Combinatorics · Mathematics 2023-11-09 Alaittin Kırtışoğlu , Lale Özkahya

A $(p,q)$-coloring of a graph $G$ is an edge-coloring of $G$ which assigns at least $q$ colors to each $p$-clique. The problem of determining the minimum number of colors, $f(n,p,q)$, needed to give a $(p,q)$-coloring of the complete graph…

Combinatorics · Mathematics 2020-06-23 Alex Cameron , Emily Heath

We present a new algorithm for the exact uniform sampling of proper \(k\)-colorings of a graph on \(n\) vertices with maximum degree~\(\Delta\). The algorithm is based on partial rejection sampling (PRS) and introduces a soft relaxation of…

Data Structures and Algorithms · Computer Science 2026-04-07 Sarat Moka , Ava Vahedi

For a graph G = (V,E) where each vertex is coloured by one of k colours, consider a subset C of V such that for each vertex v in V\C, its set of nearest neighbours in C contains at least one vertex of the same colour as v. Such a C is…

Computational Geometry · Computer Science 2023-05-31 Bubai Manna , Bodhayan Roy

In this paper we investigate the colorful components framework, motivated by applications emerging from comparative genomics. The general goal is to remove a collection of edges from an undirected vertex-colored graph $G$ such that in the…

Data Structures and Algorithms · Computer Science 2013-11-07 Anna Adamaszek , Alexandru Popa

Current quantum computing devices have different strengths and weaknesses depending on their architectures. This means that flexible approaches to circuit design are necessary. We address this task by introducing a novel space-efficient…

A proper coloring of a graph is \emph{conflict-free} if, for every non-isolated vertex, some color is used exactly once on its neighborhood. Caro, Petru\v{s}evski, and \v{S}krekovski proved that every graph $G$ has a proper conflict-free…

Combinatorics · Mathematics 2024-12-16 Daniel W. Cranston , Chun-Hung Liu

For a graph with colored vertices, a rainbow subgraph is one where all vertices have different colors. For graph $G$, let $c_k(G)$ denote the maximum number of different colors in a coloring without a rainbow path on $k$ vertices, and…

Combinatorics · Mathematics 2025-01-03 Wayne Goddard , Tyler Herrman , Simon J. Hughes

Let $G$ be a graph that admits a perfect matching. A {\sf forcing set} for a perfect matching $M$ of $G$ is a subset $S$ of $M$, such that $S$ is contained in no other perfect matching of $G$. This notion originally arose in chemistry in…

Combinatorics · Mathematics 2009-03-17 Peyman Afshani , Hamed Hatami , Ebadollah S. Mahmoodian

We show how graph neural networks can be used to solve the canonical graph coloring problem. We frame graph coloring as a multi-class node classification problem and utilize an unsupervised training strategy based on the statistical physics…

Machine Learning · Computer Science 2022-11-28 Martin J. A. Schuetz , J. Kyle Brubaker , Zhihuai Zhu , Helmut G. Katzgraber

We study the online graph coloring problem restricted to the intersection graphs of intervals with lengths in $[1,\sigma]$. For $\sigma=1$ it is the class of unit interval graphs, and for $\sigma=\infty$ the class of all interval graphs.…

For a given number of colors, $s$, the guessing number of a graph is the (base $s$) logarithm of the cardinality of the largest family of colorings of the vertex set of the graph such that the color of each vertex can be determined from the…

Combinatorics · Mathematics 2020-09-11 Jo Martin , Puck Rombach

The theory of kernelization can be used to rigorously analyze data reduction for graph coloring problems. Here, the aim is to reduce a q-Coloring input to an equivalent but smaller input whose size is provably bounded in terms of structural…

Computational Complexity · Computer Science 2018-02-07 Bart M. P. Jansen , Astrid Pieterse

The chromatic sum $\Sigma(G)$ of a graph $G$ is the smallest sum of colors among of proper coloring with the natural number. In this paper, we introduce a necessary condition for the existence of graph homomorphisms. Also, we present…

Combinatorics · Mathematics 2009-01-24 Meysam Alishahi , Ali Taherkhani

Let $G$ be a graph such that each vertex has its list of available colors, and assume that each list is a subset of the common set consisting of $k$ colors. For two given list colorings of $G$, we study the problem of transforming one into…

Data Structures and Algorithms · Computer Science 2017-05-23 Tatsuhiko Hatanaka , Takehiro Ito , Xiao Zhou

A \emph{request} on a graph assigns a preferred color to a subset of the vertices. A graph $G$ is \emph{$\epsilon$-flexibly $k$-choosable} if for every $k$-list assignment $L$ and every request $r$ on $G$, there is an $L$-coloring such that…

Combinatorics · Mathematics 2025-10-16 Peter Bradshaw , Ilkyoo Choi , Alexandr Kostochka