Edit: /usr/include/boost/graph/johnson_all_pairs_shortest.hpp (7646B)
//=======================================================================
// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
// 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)
//=======================================================================
/*
This file implements the function
template
bool
johnson_all_pairs_shortest_paths
(VertexAndEdgeListGraph& g,
DistanceMatrix& D,
const bgl_named_params& params)
*/
#ifndef BOOST_GRAPH_JOHNSON_HPP
#define BOOST_GRAPH_JOHNSON_HPP
#include
#include
#include
#include
#include
#include
#include
#include
namespace boost
{
template < class VertexAndEdgeListGraph, class DistanceMatrix, class VertexID,
class Weight, typename BinaryPredicate, typename BinaryFunction,
typename Infinity, class DistanceZero >
bool johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1,
DistanceMatrix& D, VertexID id1, Weight w1, const BinaryPredicate& compare,
const BinaryFunction& combine, const Infinity& inf, DistanceZero zero)
{
typedef graph_traits< VertexAndEdgeListGraph > Traits1;
typedef typename property_traits< Weight >::value_type DT;
BOOST_CONCEPT_ASSERT((BasicMatrixConcept< DistanceMatrix,
typename Traits1::vertices_size_type, DT >));
typedef typename Traits1::directed_category DirCat;
bool is_undirected = is_same< DirCat, undirected_tag >::value;
typedef adjacency_list< vecS, vecS, directedS,
property< vertex_distance_t, DT >,
property< edge_weight_t, DT, property< edge_weight2_t, DT > > >
Graph2;
typedef graph_traits< Graph2 > Traits2;
Graph2 g2(num_vertices(g1) + 1);
typename property_map< Graph2, edge_weight_t >::type w
= get(edge_weight, g2);
typename property_map< Graph2, edge_weight2_t >::type w_hat
= get(edge_weight2, g2);
typename property_map< Graph2, vertex_distance_t >::type d
= get(vertex_distance, g2);
typedef typename property_map< Graph2, vertex_index_t >::type VertexID2;
VertexID2 id2 = get(vertex_index, g2);
// Construct g2 where V[g2] = V[g1] U {s}
// and E[g2] = E[g1] U {(s,v)| v in V[g1]}
std::vector< typename Traits1::vertex_descriptor > verts1(
num_vertices(g1) + 1);
typename Traits2::vertex_descriptor s = *vertices(g2).first;
{
typename Traits1::vertex_iterator v, v_end;
int i = 1;
for (boost::tie(v, v_end) = vertices(g1); v != v_end; ++v, ++i)
{
typename Traits2::edge_descriptor e;
bool z;
boost::tie(e, z) = add_edge(s, get(id1, *v) + 1, g2);
put(w, e, zero);
verts1[i] = *v;
}
typename Traits1::edge_iterator e, e_end;
for (boost::tie(e, e_end) = edges(g1); e != e_end; ++e)
{
typename Traits2::edge_descriptor e2;
bool z;
boost::tie(e2, z) = add_edge(
get(id1, source(*e, g1)) + 1, get(id1, target(*e, g1)) + 1, g2);
put(w, e2, get(w1, *e));
if (is_undirected)
{
boost::tie(e2, z) = add_edge(get(id1, target(*e, g1)) + 1,
get(id1, source(*e, g1)) + 1, g2);
put(w, e2, get(w1, *e));
}
}
}
typename Traits2::vertex_iterator v, v_end, u, u_end;
typename Traits2::edge_iterator e, e_end;
shared_array_property_map< DT, VertexID2 > h(num_vertices(g2), id2);
for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
put(d, *v, inf);
put(d, s, zero);
// Using the non-named parameter versions of bellman_ford and
// dijkstra for portability reasons.
dummy_property_map pred;
bellman_visitor<> bvis;
if (bellman_ford_shortest_paths(
g2, num_vertices(g2), w, pred, d, combine, compare, bvis))
{
for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
put(h, *v, get(d, *v));
// Reweight the edges to remove negatives
for (boost::tie(e, e_end) = edges(g2); e != e_end; ++e)
{
typename Traits2::vertex_descriptor a = source(*e, g2),
b = target(*e, g2);
put(w_hat, *e, combine((get(h, a) - get(h, b)), get(w, *e)));
}
for (boost::tie(u, u_end) = vertices(g2); u != u_end; ++u)
{
dijkstra_visitor<> dvis;
dijkstra_shortest_paths(
g2, *u, pred, d, w_hat, id2, compare, combine, inf, zero, dvis);
for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
{
if (*u != s && *v != s)
{
D[get(id2, *u) - 1][get(id2, *v) - 1]
= combine((get(h, *v) - get(h, *u)), get(d, *v));
}
}
}
return true;
}
else
return false;
}
template < class VertexAndEdgeListGraph, class DistanceMatrix, class VertexID,
class Weight, class DistanceZero >
bool johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1,
DistanceMatrix& D, VertexID id1, Weight w1, DistanceZero zero)
{
typedef typename property_traits< Weight >::value_type WT;
return johnson_all_pairs_shortest_paths(g1, D, id1, w1, std::less< WT >(),
closed_plus< WT >(), (std::numeric_limits< WT >::max)(), zero);
}
namespace detail
{
template < class VertexAndEdgeListGraph, class DistanceMatrix, class P,
class T, class R, class Weight, class VertexID >
bool johnson_dispatch(VertexAndEdgeListGraph& g, DistanceMatrix& D,
const bgl_named_params< P, T, R >& params, Weight w, VertexID id)
{
typedef typename property_traits< Weight >::value_type WT;
return johnson_all_pairs_shortest_paths(g, D, id, w,
choose_param(
get_param(params, distance_compare_t()), std::less< WT >()),
choose_param(
get_param(params, distance_combine_t()), closed_plus< WT >()),
choose_param(get_param(params, distance_inf_t()),
std::numeric_limits< WT >::max
BOOST_PREVENT_MACRO_SUBSTITUTION()),
choose_param(get_param(params, distance_zero_t()), WT()));
}
} // namespace detail
template < class VertexAndEdgeListGraph, class DistanceMatrix, class P, class T,
class R >
bool johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g,
DistanceMatrix& D, const bgl_named_params< P, T, R >& params)
{
return detail::johnson_dispatch(g, D, params,
choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
choose_const_pmap(get_param(params, vertex_index), g, vertex_index));
}
template < class VertexAndEdgeListGraph, class DistanceMatrix >
bool johnson_all_pairs_shortest_paths(
VertexAndEdgeListGraph& g, DistanceMatrix& D)
{
bgl_named_params< int, int > params(1);
return detail::johnson_dispatch(
g, D, params, get(edge_weight, g), get(vertex_index, g));
}
} // namespace boost
#endif // BOOST_GRAPH_JOHNSON_HPP