boost/libs/graph/test/biconnected_components_test.cpp
2021-10-05 21:37:46 +02:00

155 lines
4.4 KiB
C++

// Copyright 2004 The Trustees of Indiana University.
// Use, modification and distribution is subject to 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)
// Authors: Douglas Gregor
// Andrew Lumsdaine
#include <boost/graph/biconnected_components.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/core/lightweight_test.hpp>
#include <boost/lexical_cast.hpp>
#include <vector>
#include <iterator>
#include <iostream>
#include <algorithm>
#include <boost/graph/connected_components.hpp>
#include <boost/graph/random.hpp>
#include <boost/random/linear_congruential.hpp>
#include <fstream>
using namespace boost;
struct EdgeProperty
{
std::size_t component;
};
static bool any_errors = false;
template < typename Graph, typename Vertex >
void check_articulation_points(const Graph& g, std::vector< Vertex > art_points)
{
std::vector< int > components(num_vertices(g));
int basic_comps = connected_components(g,
make_iterator_property_map(
components.begin(), get(vertex_index, g), int()));
std::vector< Vertex > art_points_check;
typename graph_traits< Graph >::vertex_iterator vi, vi_end;
for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
{
Graph g_copy(g);
Vertex victim = vertex(get(vertex_index, g, *vi), g_copy);
clear_vertex(victim, g_copy);
remove_vertex(victim, g_copy);
int copy_comps = connected_components(g_copy,
make_iterator_property_map(
components.begin(), get(vertex_index, g_copy), int()));
if (copy_comps > basic_comps)
art_points_check.push_back(*vi);
}
std::sort(art_points.begin(), art_points.end());
std::sort(art_points_check.begin(), art_points_check.end());
BOOST_TEST(art_points == art_points_check);
if (art_points != art_points_check)
{
std::cerr << "ERROR!" << std::endl;
std::cerr << "\tComputed: ";
std::size_t i;
for (i = 0; i < art_points.size(); ++i)
std::cout << art_points[i] << ' ';
std::cout << std::endl << "\tExpected: ";
for (i = 0; i < art_points_check.size(); ++i)
std::cout << art_points_check[i] << ' ';
std::cout << std::endl;
any_errors = true;
}
else
std::cout << "OK." << std::endl;
}
typedef adjacency_list< listS, vecS, undirectedS, no_property, EdgeProperty >
Graph;
typedef graph_traits< Graph >::vertex_descriptor Vertex;
bool test_graph(Graph& g)
{ // Returns false on failure
std::vector< Vertex > art_points;
std::cout << "Computing biconnected components & articulation points... ";
std::cout.flush();
std::size_t num_comps = biconnected_components(
g, get(&EdgeProperty::component, g), std::back_inserter(art_points))
.first;
std::cout << "done.\n\t" << num_comps << " biconnected components.\n"
<< "\t" << art_points.size() << " articulation points.\n"
<< "\tTesting articulation points...";
std::cout.flush();
check_articulation_points(g, art_points);
if (any_errors)
{
std::ofstream out("biconnected_components_test_failed.dot");
out << "graph A {\n"
<< " node[shape=\"circle\"]\n";
for (std::size_t i = 0; i < art_points.size(); ++i)
{
out << art_points[i] << " [ style=\"filled\" ];" << std::endl;
}
graph_traits< Graph >::edge_iterator ei, ei_end;
for (boost::tie(ei, ei_end) = edges(g); ei != ei_end; ++ei)
out << source(*ei, g) << " -- " << target(*ei, g) << "[label=\""
<< g[*ei].component << "\"]\n";
out << "}\n";
}
return any_errors;
}
int main(int argc, char* argv[])
{
std::size_t n = 100;
std::size_t m = 500;
std::size_t seed = 1;
if (argc > 1)
n = lexical_cast< std::size_t >(argv[1]);
if (argc > 2)
m = lexical_cast< std::size_t >(argv[2]);
if (argc > 3)
seed = lexical_cast< std::size_t >(argv[3]);
{
Graph g(n);
minstd_rand gen(seed);
generate_random_graph(g, n, m, gen);
if (test_graph(g))
return 1;
}
{
Graph g(4);
add_edge(2, 3, g);
add_edge(0, 3, g);
add_edge(0, 2, g);
add_edge(1, 0, g);
if (test_graph(g))
return 1;
}
return boost::report_errors();
}