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// Copyright Daniel Trebbien 2010.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or the copy at
// http://www.boost.org/LICENSE_1_0.txt)
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif
#include <fstream>
#include <iostream>
#include <map>
#include <vector>
#include <string>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/connected_components.hpp>
#include <boost/graph/exception.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/read_dimacs.hpp>
#include <boost/graph/stoer_wagner_min_cut.hpp>
#include <boost/graph/property_maps/constant_property_map.hpp>
#include <boost/property_map/property_map.hpp>
#include <boost/core/lightweight_test.hpp>
#include <boost/tuple/tuple.hpp>
typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::undirectedS,
boost::no_property, boost::property< boost::edge_weight_t, int > >
undirected_graph;
typedef boost::property_map< undirected_graph, boost::edge_weight_t >::type
weight_map_type;
typedef boost::property_traits< weight_map_type >::value_type weight_type;
typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::undirectedS >
undirected_unweighted_graph;
std::string test_dir;
struct edge_t
{
unsigned long first;
unsigned long second;
};
// the example from Stoer & Wagner (1997)
void test0()
{
edge_t edges[] = { { 0, 1 }, { 1, 2 }, { 2, 3 }, { 0, 4 }, { 1, 4 },
{ 1, 5 }, { 2, 6 }, { 3, 6 }, { 3, 7 }, { 4, 5 }, { 5, 6 }, { 6, 7 } };
weight_type ws[] = { 2, 3, 4, 3, 2, 2, 2, 2, 2, 3, 1, 3 };
undirected_graph g(edges, edges + 12, ws, 8, 12);
weight_map_type weights = get(boost::edge_weight, g);
std::map< int, bool > parity;
boost::associative_property_map< std::map< int, bool > > parities(parity);
int w
= boost::stoer_wagner_min_cut(g, weights, boost::parity_map(parities));
BOOST_TEST_EQ(w, 4);
const bool parity0 = get(parities, 0);
BOOST_TEST_EQ(parity0, get(parities, 1));
BOOST_TEST_EQ(parity0, get(parities, 4));
BOOST_TEST_EQ(parity0, get(parities, 5));
const bool parity2 = get(parities, 2);
BOOST_TEST_NE(parity0, parity2);
BOOST_TEST_EQ(parity2, get(parities, 3));
BOOST_TEST_EQ(parity2, get(parities, 6));
BOOST_TEST_EQ(parity2, get(parities, 7));
}
void test1()
{
{ // if only one vertex, can't run `boost::stoer_wagner_min_cut`
undirected_graph g;
add_vertex(g);
BOOST_TEST_THROWS(
boost::stoer_wagner_min_cut(g, get(boost::edge_weight, g)),
boost::bad_graph);
}
{ // three vertices with one multi-edge
typedef boost::graph_traits< undirected_graph >::vertex_descriptor
vertex_descriptor;
edge_t edges[] = { { 0, 1 }, { 1, 2 }, { 1, 2 }, { 2, 0 } };
weight_type ws[] = { 3, 1, 1, 1 };
undirected_graph g(edges, edges + 4, ws, 3, 4);
weight_map_type weights = get(boost::edge_weight, g);
std::map< int, bool > parity;
boost::associative_property_map< std::map< int, bool > > parities(
parity);
std::map< vertex_descriptor, vertex_descriptor > assignment;
boost::associative_property_map<
std::map< vertex_descriptor, vertex_descriptor > >
assignments(assignment);
int w = boost::stoer_wagner_min_cut(g, weights,
boost::parity_map(parities).vertex_assignment_map(assignments));
BOOST_TEST_EQ(w, 3);
const bool parity2 = get(parities, 2), parity0 = get(parities, 0);
BOOST_TEST_NE(parity2, parity0);
BOOST_TEST_EQ(parity0, get(parities, 1));
}
}
// example by Daniel Trebbien
void test2()
{
edge_t edges[] = { { 5, 2 }, { 0, 6 }, { 5, 6 }, { 3, 1 }, { 0, 1 },
{ 6, 3 }, { 4, 6 }, { 2, 4 }, { 5, 3 } };
weight_type ws[] = { 1, 3, 4, 6, 4, 1, 2, 5, 2 };
undirected_graph g(edges, edges + 9, ws, 7, 9);
std::map< int, bool > parity;
boost::associative_property_map< std::map< int, bool > > parities(parity);
int w = boost::stoer_wagner_min_cut(
g, get(boost::edge_weight, g), boost::parity_map(parities));
BOOST_TEST_EQ(w, 3);
const bool parity2 = get(parities, 2);
BOOST_TEST_EQ(parity2, get(parities, 4));
const bool parity5 = get(parities, 5);
BOOST_TEST_NE(parity2, parity5);
BOOST_TEST_EQ(parity5, get(parities, 3));
BOOST_TEST_EQ(parity5, get(parities, 6));
BOOST_TEST_EQ(parity5, get(parities, 1));
BOOST_TEST_EQ(parity5, get(parities, 0));
}
// example by Daniel Trebbien
void test3()
{
edge_t edges[] = { { 3, 4 }, { 3, 6 }, { 3, 5 }, { 0, 4 }, { 0, 1 },
{ 0, 6 }, { 0, 7 }, { 0, 5 }, { 0, 2 }, { 4, 1 }, { 1, 6 }, { 1, 5 },
{ 6, 7 }, { 7, 5 }, { 5, 2 }, { 3, 4 } };
weight_type ws[] = { 0, 3, 1, 3, 1, 2, 6, 1, 8, 1, 1, 80, 2, 1, 1, 4 };
undirected_graph g(edges, edges + 16, ws, 8, 16);
weight_map_type weights = get(boost::edge_weight, g);
std::map< int, bool > parity;
boost::associative_property_map< std::map< int, bool > > parities(parity);
int w
= boost::stoer_wagner_min_cut(g, weights, boost::parity_map(parities));
BOOST_TEST_EQ(w, 7);
const bool parity1 = get(parities, 1);
BOOST_TEST_EQ(parity1, get(parities, 5));
const bool parity0 = get(parities, 0);
BOOST_TEST_NE(parity1, parity0);
BOOST_TEST_EQ(parity0, get(parities, 2));
BOOST_TEST_EQ(parity0, get(parities, 3));
BOOST_TEST_EQ(parity0, get(parities, 4));
BOOST_TEST_EQ(parity0, get(parities, 6));
BOOST_TEST_EQ(parity0, get(parities, 7));
}
void test4()
{
typedef boost::graph_traits<
undirected_unweighted_graph >::vertex_descriptor vertex_descriptor;
typedef boost::graph_traits< undirected_unweighted_graph >::edge_descriptor
edge_descriptor;
edge_t edges[] = { { 0, 1 }, { 1, 2 }, { 2, 3 }, { 0, 4 }, { 1, 4 },
{ 1, 5 }, { 2, 6 }, { 3, 6 }, { 3, 7 }, { 4, 5 }, { 5, 6 }, { 6, 7 },
{ 0, 4 }, { 6, 7 } };
undirected_unweighted_graph g(edges, edges + 14, 8);
std::map< vertex_descriptor, bool > parity;
boost::associative_property_map< std::map< vertex_descriptor, bool > >
parities(parity);
std::map< vertex_descriptor, vertex_descriptor > assignment;
boost::associative_property_map<
std::map< vertex_descriptor, vertex_descriptor > >
assignments(assignment);
int w = boost::stoer_wagner_min_cut(g,
boost::make_constant_property< edge_descriptor >(weight_type(1)),
boost::vertex_assignment_map(assignments).parity_map(parities));
BOOST_TEST_EQ(w, 2);
const bool parity0 = get(parities, 0);
BOOST_TEST_EQ(parity0, get(parities, 1));
BOOST_TEST_EQ(parity0, get(parities, 4));
BOOST_TEST_EQ(parity0, get(parities, 5));
const bool parity2 = get(parities, 2);
BOOST_TEST_NE(parity0, parity2);
BOOST_TEST_EQ(parity2, get(parities, 3));
BOOST_TEST_EQ(parity2, get(parities, 6));
BOOST_TEST_EQ(parity2, get(parities, 7));
}
// Non regression test for github.com/boostorg/graph/issues/286
void test5()
{
edge_t edges[] = { { 0, 1 }, { 0, 2 }, { 0, 3 }, { 1, 2 }, { 1, 3 },
{ 2, 3 }, { 4, 5 }, { 4, 6 }, { 4, 7 }, { 5, 6 }, { 5, 7 }, { 6, 7 },
{ 0, 4 } };
weight_type ws[] = { 3, 3, 3, 2, 2, 2, 3, 3, 3, 2, 2, 2, 6 };
undirected_graph g(edges, edges + 13, ws, 8, 13);
weight_map_type weights = get(boost::edge_weight, g);
std::map< int, bool > parity;
boost::associative_property_map< std::map< int, bool > > parities(parity);
int w
= boost::stoer_wagner_min_cut(g, weights, boost::parity_map(parities));
BOOST_TEST_EQ(w, 6);
const bool parity0 = get(parities, 0);
BOOST_TEST_EQ(parity0, get(parities, 1));
BOOST_TEST_EQ(parity0, get(parities, 2));
BOOST_TEST_EQ(parity0, get(parities, 3));
const bool parity4 = get(parities, 4);
BOOST_TEST_NE(parity0, parity4);
BOOST_TEST_EQ(parity4, get(parities, 5));
BOOST_TEST_EQ(parity4, get(parities, 6));
BOOST_TEST_EQ(parity4, get(parities, 7));
}
// The input for the `test_prgen` family of tests comes from a program, named
// `prgen`, that comes with a package of min-cut solvers by Chandra Chekuri,
// Andrew Goldberg, David Karger, Matthew Levine, and Cliff Stein. `prgen` was
// used to generate input graphs and the solvers were used to verify the return
// value of `boost::stoer_wagner_min_cut` on the input graphs.
//
// http://www.columbia.edu/~cs2035/code.html
//
// Note that it is somewhat more difficult to verify the parities because
// "`prgen` graphs" often have several min-cuts. This is why only the cut
// weight of the min-cut is verified.
// 3 min-cuts
void test_prgen_20_70_2()
{
typedef boost::graph_traits< undirected_graph >::vertex_descriptor
vertex_descriptor;
std::ifstream ifs(
(test_dir + "/prgen_input_graphs/prgen_20_70_2.net").c_str());
undirected_graph g;
boost::read_dimacs_min_cut(
g, get(boost::edge_weight, g), boost::dummy_property_map(), ifs);
std::map< vertex_descriptor, std::size_t > component;
boost::associative_property_map<
std::map< vertex_descriptor, std::size_t > >
components(component);
BOOST_TEST_EQ(boost::connected_components(g, components),
1U); // verify the connectedness assumption
typedef boost::shared_array_property_map< weight_type,
boost::property_map< undirected_graph,
boost::vertex_index_t >::const_type >
distances_type;
distances_type distances = boost::make_shared_array_property_map(
num_vertices(g), weight_type(0), get(boost::vertex_index, g));
typedef std::vector< vertex_descriptor >::size_type index_in_heap_type;
typedef boost::shared_array_property_map< index_in_heap_type,
boost::property_map< undirected_graph,
boost::vertex_index_t >::const_type >
indicesInHeap_type;
indicesInHeap_type indicesInHeap = boost::make_shared_array_property_map(
num_vertices(g), index_in_heap_type(-1), get(boost::vertex_index, g));
boost::d_ary_heap_indirect< vertex_descriptor, 22, indicesInHeap_type,
distances_type, std::greater< weight_type > >
pq(distances, indicesInHeap);
int w = boost::stoer_wagner_min_cut(
g, get(boost::edge_weight, g), boost::max_priority_queue(pq));
BOOST_TEST_EQ(w, 3407);
}
// 7 min-cuts
void test_prgen_50_40_2()
{
typedef boost::graph_traits< undirected_graph >::vertex_descriptor
vertex_descriptor;
std::ifstream ifs(
(test_dir + "/prgen_input_graphs/prgen_50_40_2.net").c_str());
undirected_graph g;
boost::read_dimacs_min_cut(
g, get(boost::edge_weight, g), boost::dummy_property_map(), ifs);
std::map< vertex_descriptor, std::size_t > component;
boost::associative_property_map<
std::map< vertex_descriptor, std::size_t > >
components(component);
BOOST_TEST_EQ(boost::connected_components(g, components),
1U); // verify the connectedness assumption
int w = boost::stoer_wagner_min_cut(g, get(boost::edge_weight, g));
BOOST_TEST_EQ(w, 10056);
}
// 6 min-cuts
void test_prgen_50_70_2()
{
typedef boost::graph_traits< undirected_graph >::vertex_descriptor
vertex_descriptor;
std::ifstream ifs(
(test_dir + "/prgen_input_graphs/prgen_50_70_2.net").c_str());
undirected_graph g;
boost::read_dimacs_min_cut(
g, get(boost::edge_weight, g), boost::dummy_property_map(), ifs);
std::map< vertex_descriptor, std::size_t > component;
boost::associative_property_map<
std::map< vertex_descriptor, std::size_t > >
components(component);
BOOST_TEST_EQ(boost::connected_components(g, components),
1U); // verify the connectedness assumption
int w = boost::stoer_wagner_min_cut(g, get(boost::edge_weight, g));
BOOST_TEST_EQ(w, 21755);
}
int main(int argc, char* argv[])
{
if (BOOST_TEST(argc == 2))
{
test_dir = argv[1];
test0();
test1();
test2();
test3();
test4();
test5();
test_prgen_20_70_2();
test_prgen_50_70_2();
}
return boost::report_errors();
}
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