Concept

Coloration des arêtes d'un graphe

Publications associées (169)

Graph Chatbot

Chattez avec Graph Search

Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.

AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.

Connectez-vous pour utiliser Chat avec Graph Search

On a graph coloring problem arising from discrete tomography

Dominique de Werra, Bernard Ries

An extension of the basic image reconstruction problem in discrete tomography is considered: given a graph

G=(V,E)

and a family

\mathcal{P}

of chains

P_i

together with vectors

h(P_i)=(h_{i}^{1},...,h_{i}^{k})

, one wants to find a partition $V^{1},. ...

2008

On two coloring problems in mixed graphs

Dominique de Werra, Bernard Ries

We are interested in coloring the vertices of a mixed graph, i.e., a graph containing edges and arcs. We consider two different coloring problems: in the first one we want adjacent vertices to have different colors and the tail of an arc to get a color str ...

2008

Variable space search for graph coloring

Nicolas Zufferey, Matthieu Plumettaz

Let G = (V, E) be a graph with vertex set V and edge set E. The k-coloring problem is to assign a color (a number chosen in {1, ..., k}) to each vertex of G so that no edge has both endpoints with the same color. We propose a new local search methodology, ...

2008

Complexity of mixed graph coloring

Bernard Ries

In this note we consider two coloring problems in mixed graphs, i.e., graphs containing edges and arcs. We show that they are both

\mathcal{NP}

-complete in cubic planar bipartite graphs. This answers an open question from \cite{Ries2}. ...

2008

Drawing cubic graphs with at most five slopes

János Pach, Balázs Keszegh

We show that every graph G with maximum degree three has a straight-line drawing in the plane using edges of at most five different slopes. Moreover, if G is connected and has at least one vertex of degree less than three, then four directions suffice. ...

2008

Graph colouring approaches for a satellite range scheduling problem

Nicolas Zufferey, Patrick Amstutz, Philippe Giaccari

A goal of this paper is to efficiently adapt the best ingredients of the graph colouring techniques to an NP-hard satellite range scheduling problem, called MuRRSP. We propose two new heuristics for the MuRRSP, where as many jobs as possible have to be sch ...

2008

Coloring some classes of mixed graphs

Bernard Ries

We consider the coloring problem for mixed graphs, that is, for graphs containing edges and arcs. A mixed coloring

c

is a coloring such that for every edge

[x_{i},x_{j}]

c(x_{i})\neq c(x_{j})

and for every arc

(x_{p},x_{q})

, $c(x_{p})

2007

Variations of coloring problems related to scheduling and discrete tomography

Bernard Ries

The graph coloring problem is one of the most famous problems in graph theory and has a large range of applications. It consists in coloring the vertices of an undirected graph with a given number of colors such that two adjacent vertices get different col ...

EPFL2007

Bicolored matchings in some classes of graphs

Dominique de Werra, Bernard Ries

We consider the problem of finding in a graph a set

R

of edges to be colored in red so that there are maximum matchings having some prescribed numbers of red edges. For regular bipartite graphs with

n

nodes on each side, we give sufficient conditions f ...

2007

Online Coloring of Comparability Graphs: some results

Benjamin Leroy-Beaulieu

We study online partitioning of posets from a graph theoretical point of view, which is coloring and cocoloring in comparability graphs. For the coloring problem, we analyse the First-Fit algorithm and show a ratio of