\name{sequential.vertex.coloring}
\alias{sequential.vertex.coloring}
\title{Compute a vertex coloring for a graph}
\description{Compute vertex coloring for a graph}

\usage{
sequential.vertex.coloring(g)
}

\arguments{
  \item{g}{an instance of the \code{graph} class} 
}

\details{
A vertex coloring for a graph is to assign a color for each vertex so that no 
two adjacent vertices are of the same color.  We designate the colors as 
sequential integers: 1, 2, ....

For ordered vertices, \code{v1}, \code{v2}, ..., \code{vn}, for k = 1, 2, ..., 
n, this algorithm assigns \code{vk} to the smallest possible color.  It does 
NOT guarantee to use minimum number of colors.

See documentations on these algorithms in Boost Graph Library for more details.
}

\value{
\item{no. of colors needed}{how many colors to use to color the graph}
\item{colors of nodes}{ color label for each vertex }
}

\references{
Boost Graph Library ( www.boost.org/libs/graph/doc/index.html )

The Boost Graph Library: User Guide and Reference Manual;
by Jeremy G. Siek, Lie-Quan Lee, and Andrew Lumsdaine;
(Addison-Wesley, Pearson Education Inc., 2002), xxiv+321pp.
ISBN 0-201-72914-8
}

\author{Li Long <li.long@isb-sib.ch>}

\seealso{}

\examples{
con <- file(system.file("XML/dijkex.gxl",package="RBGL"), open="r")
coex <- fromGXL(con)
close(con)
sequential.vertex.coloring(coex)
}
\keyword{ models }