Results 171 to 180 of about 8,657,296 (197)

On the Chromatic Number of Graphs

Journal of Optimization Theory and Applications, 2001
Computing the chromatic number of a graph is NP-hard---in fact, it is NP-hard to colour a graph with fewer than twice the minimum number of colours [\textit{M. R. Garey} and \textit{D. S. Johnson}, The complexity of near-optimal graph coloring, J. Assoc. Comput. Mach. 23, 43-49 (1976; Zbl 0322.05111)].
FESTA, PAOLA, S. BUTENKO, P. M. PARDALOS
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Star chromatic number

Journal of Graph Theory, 1988
AbstractA generalization of the chromatic number of a graph is introduced such that the colors are integers modulo n, and the colors on adjacent vertices are required to be as far apart as possible.
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On Group Chromatic Number of Graphs

Graphs and Combinatorics, 2005
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Hong-Jian Lai, Xiangwen Li
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The Sigma Chromatic Number of a Graph

Graphs and Combinatorics, 2010
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Gary Chartrand, Futaba Okamoto, Ping Zhang 0004   +2 more
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The difference between game chromatic number and chromatic number of graphs

Information Processing Letters, 2019
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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Determining the Chromatic Number of a Graph

SIAM Journal on Computing, 1979
Certain branch-and-bound algorithms for determining the chromatic number of a graph are proved usually to take a number of steps which grows faster than exponentially with the number of vertices in the graph. A similar result holds for the number of steps in certain proofs of lower bounds for chromatic numbers.
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Game chromatic number of outerplanar graphs

Journal of Graph Theory, 1999
Xuding Zhu
exaly  

New bounds for chromatic polynomials and chromatic roots

Discrete Mathematics, 2015
Aysel Erey, Jason Brown
exaly  

Bounds for the b-chromatic number of some families of graphs

Discrete Mathematics, 2006
Manouchehr Zaker
exaly  

The b-chromatic number and related topics—A survey

Discrete Applied Mathematics, 2018
Iztok Peterin, Marko Jakovac
exaly