bellman-test.cpp
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// (C) Copyright Jeremy Siek 2004
// 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)
// From Louis Lavery <Louis@devilsChimney.co.uk>
/*Expected Output:-
A: 0 A
B: 11 A
Actual Output:-
A: 0 A
B: 2147483647 B
*/
#include <iostream>
#include <iomanip>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/bellman_ford_shortest_paths.hpp>
#include <boost/cstdlib.hpp>
#include <boost/core/lightweight_test.hpp>
int main(int, char*[])
{
using namespace boost;
enum
{
A,
B,
Z
};
char const name[] = "ABZ";
int const numVertex = static_cast< int >(Z) + 1;
typedef std::pair< int, int > Edge;
Edge edge_array[] = { Edge(B, A) };
int const numEdges = sizeof(edge_array) / sizeof(Edge);
int const weight[numEdges] = { 11 };
typedef adjacency_list< vecS, vecS, undirectedS, no_property,
property< edge_weight_t, int > >
Graph;
Graph g(edge_array, edge_array + numEdges, numVertex);
Graph::edge_iterator ei, ei_end;
property_map< Graph, edge_weight_t >::type weight_pmap
= get(edge_weight, g);
int i = 0;
for (boost::tie(ei, ei_end) = edges(g); ei != ei_end; ++ei, ++i)
weight_pmap[*ei] = weight[i];
std::vector< int > parent(numVertex);
for (i = 0; i < numVertex; ++i)
parent[i] = i;
int inf = (std::numeric_limits< int >::max)();
std::vector< int > distance(numVertex, inf);
distance[A] = 0; // Set source distance to zero
bool const r = bellman_ford_shortest_paths(g, int(numVertex), weight_pmap,
boost::make_iterator_property_map(
parent.begin(), get(boost::vertex_index, g)),
boost::make_iterator_property_map(
distance.begin(), get(boost::vertex_index, g)),
closed_plus< int >(), std::less< int >(), default_bellman_visitor());
if (r)
{
for (int i = 0; i < numVertex; ++i)
{
std::cout << name[i] << ": ";
if (distance[i] == inf)
std::cout << std::setw(3) << "inf";
else
std::cout << std::setw(3) << distance[i];
std::cout << " " << name[parent[i]] << std::endl;
}
}
else
{
std::cout << "negative cycle" << std::endl;
}
#if !(defined(__INTEL_COMPILER) && __INTEL_COMPILER <= 700) \
&& !(defined(BOOST_MSVC) && BOOST_MSVC <= 1300)
graph_traits< Graph >::vertex_descriptor s = vertex(A, g);
std::vector< int > parent2(numVertex);
std::vector< int > distance2(numVertex, 17);
bool const r2 = bellman_ford_shortest_paths(g,
weight_map(weight_pmap)
.distance_map(boost::make_iterator_property_map(
distance2.begin(), get(boost::vertex_index, g)))
.predecessor_map(boost::make_iterator_property_map(
parent2.begin(), get(boost::vertex_index, g)))
.root_vertex(s));
if (r2)
{
for (int i = 0; i < numVertex; ++i)
{
std::cout << name[i] << ": ";
if (distance2[i] == inf)
std::cout << std::setw(3) << "inf";
else
std::cout << std::setw(3) << distance2[i];
std::cout << " " << name[parent2[i]] << std::endl;
}
}
else
{
std::cout << "negative cycle" << std::endl;
}
BOOST_TEST(r == r2);
if (r && r2)
{
BOOST_TEST(parent == parent2);
BOOST_TEST(distance == distance2);
}
#endif
return boost::report_errors();
}