1 files changed, 134 insertions, 0 deletions
diff --git a/src/boost/libs/graph/example/bellman-example.cpp b/src/boost/libs/graph/example/bellman-example.cpp
new file mode 100644
index 000000000..69bce6397
--- /dev/null
+++ b/src/boost/libs/graph/example/bellman-example.cpp
@@ -0,0 +1,134 @@
+//=======================================================================
+// Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee,
+//
+// 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 <vector>
+#include <iostream>
+#include <fstream>
+#include <iomanip>
+#include <boost/graph/adjacency_list.hpp>
+#include <boost/graph/bellman_ford_shortest_paths.hpp>
+
+using namespace boost;
+
+template < typename Graph, typename ParentMap > struct edge_writer
+{
+    edge_writer(const Graph& g, const ParentMap& p) : m_g(g), m_parent(p) {}
+
+    template < typename Edge >
+    void operator()(std::ostream& out, const Edge& e) const
+    {
+        out << "[label=\"" << get(edge_weight, m_g, e) << "\"";
+        typename graph_traits< Graph >::vertex_descriptor u = source(e, m_g),
+                                                          v = target(e, m_g);
+        if (m_parent[v] == u)
+            out << ", color=\"black\"";
+        else
+            out << ", color=\"grey\"";
+        out << "]";
+    }
+    const Graph& m_g;
+    ParentMap m_parent;
+};
+template < typename Graph, typename Parent >
+edge_writer< Graph, Parent > make_edge_writer(const Graph& g, const Parent& p)
+{
+    return edge_writer< Graph, Parent >(g, p);
+}
+
+struct EdgeProperties
+{
+    int weight;
+};
+
+int main()
+{
+    enum
+    {
+        u,
+        v,
+        x,
+        y,
+        z,
+        N
+    };
+    char name[] = { 'u', 'v', 'x', 'y', 'z' };
+    typedef std::pair< int, int > E;
+    const int n_edges = 10;
+    E edge_array[] = { E(u, y), E(u, x), E(u, v), E(v, u), E(x, y), E(x, v),
+        E(y, v), E(y, z), E(z, u), E(z, x) };
+    int weight[n_edges] = { -4, 8, 5, -2, 9, -3, 7, 2, 6, 7 };
+
+    typedef adjacency_list< vecS, vecS, directedS, no_property, EdgeProperties >
+        Graph;
+#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
+    // VC++ can't handle the iterator constructor
+    Graph g(N);
+    for (std::size_t j = 0; j < n_edges; ++j)
+        add_edge(edge_array[j].first, edge_array[j].second, g);
+#else
+    Graph g(edge_array, edge_array + n_edges, N);
+#endif
+    graph_traits< Graph >::edge_iterator ei, ei_end;
+    property_map< Graph, int EdgeProperties::* >::type weight_pmap
+        = get(&EdgeProperties::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 > distance(N, (std::numeric_limits< short >::max)());
+    std::vector< std::size_t > parent(N);
+    for (i = 0; i < N; ++i)
+        parent[i] = i;
+    distance[z] = 0;
+
+#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
+    bool r = bellman_ford_shortest_paths(g, int(N), weight_pmap, &parent[0],
+        &distance[0], closed_plus< int >(), std::less< int >(),
+        default_bellman_visitor());
+#else
+    bool r = bellman_ford_shortest_paths(g, int(N),
+        weight_map(weight_pmap)
+            .distance_map(&distance[0])
+            .predecessor_map(&parent[0]));
+#endif
+
+    if (r)
+        for (i = 0; i < N; ++i)
+            std::cout << name[i] << ": " << std::setw(3) << distance[i] << " "
+                      << name[parent[i]] << std::endl;
+    else
+        std::cout << "negative cycle" << std::endl;
+
+    std::ofstream dot_file("figs/bellman-eg.dot");
+    dot_file << "digraph D {\n"
+             << "  rankdir=LR\n"
+             << "  size=\"5,3\"\n"
+             << "  ratio=\"fill\"\n"
+             << "  edge[style=\"bold\"]\n"
+             << "  node[shape=\"circle\"]\n";
+
+    {
+        for (boost::tie(ei, ei_end) = edges(g); ei != ei_end; ++ei)
+        {
+            graph_traits< Graph >::edge_descriptor e = *ei;
+            graph_traits< Graph >::vertex_descriptor u = source(e, g),
+                                                     v = target(e, g);
+            // VC++ doesn't like the 3-argument get function, so here
+            // we workaround by using 2-nested get()'s.
+            dot_file << name[u] << " -> " << name[v] << "[label=\""
+                     << get(get(&EdgeProperties::weight, g), e) << "\"";
+            if (parent[v] == u)
+                dot_file << ", color=\"black\"";
+            else
+                dot_file << ", color=\"grey\"";
+            dot_file << "]";
+        }
+    }
+    dot_file << "}";
+    return EXIT_SUCCESS;
+}