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// -*- c++ -*-
//=======================================================================
// 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)
//=======================================================================
#include <boost/config.hpp>
#include <iostream>
#include <boost/graph/adjacency_list.hpp>
/*
Thanks to Dale Gerdemann for this example, which inspired some
changes to adjacency_list to make this work properly.
*/
/*
Sample output:
0 --c--> 1 --j--> 1 --c--> 2 --x--> 2
1 --c--> 2 --d--> 3
2 --t--> 4
3 --h--> 4
4
merging vertex 1 into vertex 0
0 --c--> 0 --j--> 0 --c--> 1 --x--> 1 --d--> 2
1 --t--> 3
2 --h--> 3
3
*/
// merge_vertex(u,v,g):
// incoming/outgoing edges for v become incoming/outgoing edges for u
// v is deleted
template <class Graph, class GetEdgeProperties>
void merge_vertex
(typename boost::graph_traits<Graph>::vertex_descriptor u,
typename boost::graph_traits<Graph>::vertex_descriptor v,
Graph& g, GetEdgeProperties getp)
{
typedef boost::graph_traits<Graph> Traits;
typename Traits::edge_descriptor e;
typename Traits::out_edge_iterator out_i, out_end;
for (tie(out_i, out_end) = out_edges(v, g); out_i != out_end; ++out_i) {
e = *out_i;
typename Traits::vertex_descriptor targ = target(e, g);
add_edge(u, targ, getp(e), g);
}
typename Traits::in_edge_iterator in_i, in_end;
for (tie(in_i, in_end) = in_edges(v, g); in_i != in_end; ++in_i) {
e = *in_i;
typename Traits::vertex_descriptor src = source(e, g);
add_edge(src, u, getp(e), g);
}
clear_vertex(v, g);
remove_vertex(v, g);
}
template <class StoredEdge>
struct order_by_name
: public std::binary_function<StoredEdge,StoredEdge,bool>
{
bool operator()(const StoredEdge& e1, const StoredEdge& e2) const {
// Using std::pair operator< as an easy way to get lexicographical
// compare over tuples.
return std::make_pair(e1.get_target(), boost::get(boost::edge_name, e1))
< std::make_pair(e2.get_target(), boost::get(boost::edge_name, e2));
}
};
struct ordered_set_by_nameS { };
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
namespace boost {
template <class ValueType>
struct container_gen<ordered_set_by_nameS, ValueType> {
typedef std::set<ValueType, order_by_name<ValueType> > type;
};
template <>
struct parallel_edge_traits<ordered_set_by_nameS> {
typedef allow_parallel_edge_tag type;
};
}
#endif
template <class Graph>
struct get_edge_name {
get_edge_name(const Graph& g_) : g(g_) { }
template <class Edge>
boost::property<boost::edge_name_t, char> operator()(Edge e) const {
return boost::property<boost::edge_name_t, char>(boost::get(boost::edge_name, g, e));
}
const Graph& g;
};
int
main()
{
#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
std::cout << "This program requires partial specialization." << std::endl;
#else
using namespace boost;
typedef property<edge_name_t, char> EdgeProperty;
typedef adjacency_list<ordered_set_by_nameS, vecS, bidirectionalS,
no_property, EdgeProperty> graph_type;
graph_type g;
add_edge(0, 1, EdgeProperty('j'), g);
add_edge(0, 2, EdgeProperty('c'), g);
add_edge(0, 2, EdgeProperty('x'), g);
add_edge(1, 3, EdgeProperty('d'), g);
add_edge(1, 2, EdgeProperty('c'), g);
add_edge(1, 3, EdgeProperty('d'), g);
add_edge(2, 4, EdgeProperty('t'), g);
add_edge(3, 4, EdgeProperty('h'), g);
add_edge(0, 1, EdgeProperty('c'), g);
property_map<graph_type, vertex_index_t>::type id = get(vertex_index, g);
property_map<graph_type, edge_name_t>::type name = get(edge_name, g);
graph_traits<graph_type>::vertex_iterator i, end;
graph_traits<graph_type>::out_edge_iterator ei, edge_end;
for (boost::tie(i, end) = vertices(g); i != end; ++i) {
std::cout << id[*i] << " ";
for (boost::tie(ei, edge_end) = out_edges(*i, g); ei != edge_end; ++ei)
std::cout << " --" << name[*ei] << "--> " << id[target(*ei, g)] << " ";
std::cout << std::endl;
}
std::cout << std::endl;
std::cout << "merging vertex 1 into vertex 0" << std::endl << std::endl;
merge_vertex(0, 1, g, get_edge_name<graph_type>(g));
for (boost::tie(i, end) = vertices(g); i != end; ++i) {
std::cout << id[*i] << " ";
for (boost::tie(ei, edge_end) = out_edges(*i, g); ei != edge_end; ++ei)
std::cout << " --" << name[*ei] << "--> " << id[target(*ei, g)] << " ";
std::cout << std::endl;
}
std::cout << std::endl;
#endif
return 0;
}
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