Edit: /usr/include/boost/graph/sequential_vertex_coloring.hpp (4562B)
//=======================================================================
// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
// Copyright 2004 The Trustees of Indiana University
// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================
#ifndef BOOST_GRAPH_SEQUENTIAL_VERTEX_COLORING_HPP
#define BOOST_GRAPH_SEQUENTIAL_VERTEX_COLORING_HPP
#include
#include
#include
#include
#include
#ifdef BOOST_NO_TEMPLATED_ITERATOR_CONSTRUCTORS
#include
#endif
/* This algorithm is to find coloring of a graph
Algorithm:
Let G = (V,E) be a graph with vertices (somehow) ordered v_1, v_2, ...,
v_n. For k = 1, 2, ..., n the sequential algorithm assigns v_k to the
smallest possible color.
Reference:
Thomas F. Coleman and Jorge J. More, Estimation of sparse Jacobian
matrices and graph coloring problems. J. Numer. Anal. V20, P187-209, 1983
v_k is stored as o[k] here.
The color of the vertex v will be stored in color[v].
i.e., vertex v belongs to coloring color[v] */
namespace boost
{
template < class VertexListGraph, class OrderPA, class ColorMap >
typename property_traits< ColorMap >::value_type sequential_vertex_coloring(
const VertexListGraph& G, OrderPA order, ColorMap color)
{
typedef graph_traits< VertexListGraph > GraphTraits;
typedef typename GraphTraits::vertex_descriptor Vertex;
typedef typename property_traits< ColorMap >::value_type size_type;
size_type max_color = 0;
const size_type V = num_vertices(G);
// We need to keep track of which colors are used by
// adjacent vertices. We do this by marking the colors
// that are used. The mark array contains the mark
// for each color. The length of mark is the
// number of vertices since the maximum possible number of colors
// is the number of vertices.
std::vector< size_type > mark(V,
std::numeric_limits< size_type >::max
BOOST_PREVENT_MACRO_SUBSTITUTION());
// Initialize colors
typename GraphTraits::vertex_iterator v, vend;
for (boost::tie(v, vend) = vertices(G); v != vend; ++v)
put(color, *v, V - 1);
// Determine the color for every vertex one by one
for (size_type i = 0; i < V; i++)
{
Vertex current = get(order, i);
typename GraphTraits::adjacency_iterator v, vend;
// Mark the colors of vertices adjacent to current.
// i can be the value for marking since i increases successively
for (boost::tie(v, vend) = adjacent_vertices(current, G); v != vend;
++v)
mark[get(color, *v)] = i;
// Next step is to assign the smallest un-marked color
// to the current vertex.
size_type j = 0;
// Scan through all useable colors, find the smallest possible
// color that is not used by neighbors. Note that if mark[j]
// is equal to i, color j is used by one of the current vertex's
// neighbors.
while (j < max_color && mark[j] == i)
++j;
if (j == max_color) // All colors are used up. Add one more color
++max_color;
// At this point, j is the smallest possible color
put(color, current, j); // Save the color of vertex current
}
return max_color;
}
template < class VertexListGraph, class ColorMap >
typename property_traits< ColorMap >::value_type sequential_vertex_coloring(
const VertexListGraph& G, ColorMap color)
{
typedef typename graph_traits< VertexListGraph >::vertex_descriptor
vertex_descriptor;
typedef typename graph_traits< VertexListGraph >::vertex_iterator
vertex_iterator;
std::pair< vertex_iterator, vertex_iterator > v = vertices(G);
#ifndef BOOST_NO_TEMPLATED_ITERATOR_CONSTRUCTORS
std::vector< vertex_descriptor > order(v.first, v.second);
#else
std::vector< vertex_descriptor > order;
order.reserve(std::distance(v.first, v.second));
while (v.first != v.second)
order.push_back(*v.first++);
#endif
return sequential_vertex_coloring(G,
make_iterator_property_map(order.begin(), identity_property_map(),
graph_traits< VertexListGraph >::null_vertex()),
color);
}
}
#endif