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A mixed graph has a set of vertices, a set of undirected egdes, and a set of directed arcs. A proper coloring of a mixed graph $G$ is a function $c$ that assigns to each vertex in $G$ a positive integer such that, for each edge $uv$ in $G$,…

Discrete Mathematics · Computer Science 2024-08-09 Grzegorz Gutowski , Florian Mittelstädt , Ignaz Rutter , Joachim Spoerhase , Alexander Wolff , Johannes Zink

An \emph{interval $t$-coloring} of a graph $G$ is a proper edge-coloring with colors $1,\dots,t$ such that the colors on the edges incident to every vertex of $G$ are colored by consecutive colors. A graph $G$ is called \emph{interval…

Combinatorics · Mathematics 2024-09-27 Petros A. Petrosyan , Hrant H. Khachatrian , Hovhannes G. Tananyan

A mixed graph contains (undirected) edges as well as (directed) arcs, thus generalizing undirected and directed graphs. A proper coloring $c$ of a mixed graph $G$ assigns a positive integer to each vertex such that $c(u)\neq c(v)$ for every…

Computational Complexity · Computer Science 2026-05-01 Antonio Lauerbach , Konstanty Junosza-Szaniawski , Marie Diana Sieper , Alexander Wolff

An improper interval (edge) coloring of a graph $G$ is an assignment of colors to the edges of $G$ satisfying the condition that, for every vertex $v \in V(G)$, the set of colors assigned to the edges incident with $v$ forms an integral…

Combinatorics · Mathematics 2024-06-03 MacKenzie Carr , Eun-Kyung Cho , Nicholas Crawford , Vesna Iršič , Leilani Pai , Rebecca Robinson

We introduce a generalization of the well known graph (vertex) coloring problem, which we call the problem of \emph{component coloring of graphs}. Given a graph, the problem is to color the vertices using minimum number of colors so that…

Discrete Mathematics · Computer Science 2012-11-06 Ajit Diwan , Soumitra Pal , Abhiram Ranade

A proper edge-coloring of a graph $G$ with colors $1,\ldots,t$ is called an \emph{interval cyclic $t$-coloring} if all colors are used, and the edges incident to each vertex $v\in V(G)$ are colored by $d_{G}(v)$ consecutive colors modulo…

Combinatorics · Mathematics 2014-11-04 Petros A. Petrosyan , Sargis T. Mkhitaryan

A \emph{mixed graph} is a graph with directed edges, called arcs, and undirected edges. A $k$-coloring of the vertices is proper if colors from ${1,2,...,k}$ are assigned to each vertex such that $u$ and $v$ have different colors if $uv$ is…

Combinatorics · Mathematics 2016-05-10 Matthias Beck , Daniel Blado , Joseph Crawford , Taina Jean-Louis , Michael Young

A $k$-improper edge coloring of a graph $G$ is a mapping $\alpha:E(G)\longrightarrow \mathbb{N}$ such that at most $k$ edges of $G$ with a common endpoint have the same color. An improper edge coloring of a graph $G$ is called an improper…

Combinatorics · Mathematics 2020-03-16 Carl Johan Casselgren , Petros A. Petrosyan

An edge-coloring of a graph $G$ with consecutive integers $c_{1},\ldots,c_{t}$ is called an \emph{interval $t$-coloring} if all colors are used, and the colors of edges incident to any vertex of $G$ are distinct and form an interval of…

Combinatorics · Mathematics 2015-08-04 Petros A. Petrosyan , Hayk H. Tepanyan

A graph $G$ is called interval colorable if it has a proper edge coloring with colors $1,2,3,\dots$ such that the colors of the edges incident to every vertex of $G$ form an interval of integers. Not all graphs are interval colorable; in…

Combinatorics · Mathematics 2021-06-08 Armen S. Asratian , Carl Johan Casselgren , Petros A. Petrosyan

An edge-coloring of a graph $G$ with colors $1,\ldots,t$ is an \emph{interval $t$-coloring} if all colors are used, and the colors of edges incident to each vertex of $G$ are distinct and form an integer interval. It is well-known that…

Combinatorics · Mathematics 2019-12-04 Armen R. Davtyan , Gevorg M. Minasyan , Petros A. Petrosyan

An \emph{interval $t$-coloring} of a multigraph $G$ is a proper edge coloring with colors $1,\dots,t$ such that the colors on the edges incident to every vertex of $G$ are colored by consecutive colors. A \emph{cyclic interval $t$-coloring}…

Combinatorics · Mathematics 2016-11-22 Carl Johan Casselgren , Hrant H. Khachatrian , Petros A. Petrosyan

A proper edge coloring of a graph $G$ with colors $1,2,\dots,t$ is called a \emph{cyclic interval $t$-coloring} if for each vertex $v$ of $G$ the edges incident to $v$ are colored by consecutive colors, under the condition that color $1$ is…

Combinatorics · Mathematics 2017-03-30 Armen S. Asratian , Carl Johan Casselgren , Petros A. Petrosyan

Let $G=(V_1(G),V_2(G),E(G))$ be a bipartite multigraph, and $R\subseteq V_1(G)\cup V_2(G)$. A proper coloring of edges of $G$ with the colors $1,\ldots,t$ is called interval (respectively, continuous) on $R$, if each color is used for at…

Discrete Mathematics · Computer Science 2014-02-03 A. S. Asratian , R. R. Kamalian

An edge-coloring of a graph $G$ with colors $1,\ldots,t$ is called an \emph{interval $t$-coloring} if all colors are used and the colors of edges incident to each vertex of $G$ are distinct and form an interval of integers. In 1990,…

Discrete Mathematics · Computer Science 2023-03-22 Arsen Hambardzumyan , Levon Muradyan

A total coloring of a graph $G$ is a coloring of its vertices and edges such that no adjacent vertices, edges, and no incident vertices and edges obtain the same color. An \emph{interval total $t$-coloring} of a graph $G$ is a total…

Discrete Mathematics · Computer Science 2010-10-15 P. A. Petrosyan , A. Yu. Torosyan , N. A. Khachatryan

A proper edge $t$-coloring of a graph $G$ is a coloring of edges of $G$ with colors $1,2,...,t$ such that all colors are used, and no two adjacent edges receive the same color. The set of colors of edges incident with a vertex $x$ is called…

Discrete Mathematics · Computer Science 2012-05-02 R. R. Kamalian

A graph is said to be interval colourable if it admits a proper edge-colouring using palette $\mathbb{N}$ in which the set of colours incident to each vertex is an interval. The interval colouring thickness of a graph $G$ is the minimum $k$…

An interval colouring of a graph $G=(V,E)$ is a proper colouring $c\colon E\to \mathbb{Z}$ such that the set of colours of edges incident to any given vertex forms an interval of $\mathbb{Z}$. The interval thickness $\theta(G)$ of a graph…

Combinatorics · Mathematics 2023-05-30 Lawrence Hollom , Julien Portier , Leo Versteegen

An edge-coloring of a graph $G$ with colors $1,2,\ldots,t$ is an interval $t$-coloring if all colors are used, and the colors of edges incident to each vertex of $G$ are distinct and form an interval of integers. A graph $G$ is interval…

Discrete Mathematics · Computer Science 2016-04-01 Hrant H. Khachatrian , Petros A. Petrosyan
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