1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
// -*- 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 (boost::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 (boost::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
{
typedef StoredEdge first_argument_type;
typedef StoredEdge second_argument_type;
typedef bool result_type;
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;
}
|
