Merged Boost.Graph, Boost.Graph.Parallel, and Boost.PropertyMap changes from Boost trunk

[SVN r85813]

example/hawick_circuits.cpp

@@ -0,0 +1,96 @@
+// Copyright Louis Dionne 2013
+
+// 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)
+
+#include <boost/assert.hpp>
+#include <boost/graph/directed_graph.hpp>
+#include <boost/graph/graph_traits.hpp>
+#include <boost/graph/hawick_circuits.hpp>
+#include <boost/lexical_cast.hpp>
+#include <boost/next_prior.hpp>
+#include <boost/property_map/property_map.hpp>
+#include <cstdlib>
+#include <iostream>
+#include <iterator>
+#include <map>
+
+
+template <typename OutputStream>
+struct cycle_printer
+{
+    cycle_printer(OutputStream& stream)
+        : os(stream)
+    { }
+
+    template <typename Path, typename Graph>
+    void cycle(Path const& p, Graph const& g)
+    {
+        if (p.empty())
+            return;
+
+        // Get the property map containing the vertex indices
+        // so we can print them.
+        typedef typename boost::property_map<
+                    Graph, boost::vertex_index_t
+                >::const_type IndexMap;
+
+        IndexMap indices = get(boost::vertex_index, g);
+
+        // Iterate over path printing each vertex that forms the cycle.
+        typename Path::const_iterator i, before_end = boost::prior(p.end());
+        for (i = p.begin(); i != before_end; ++i) {
+            os << get(indices, *i) << " ";
+        }
+        os << get(indices, *i) << '\n';
+    }
+    OutputStream& os;
+};
+
+
+// VertexPairIterator is an iterator over pairs of whitespace separated
+// vertices `u` and `v` representing a directed edge from `u` to `v`.
+template <typename Graph, typename VertexPairIterator>
+void build_graph(Graph& graph, unsigned int const nvertices,
+                 VertexPairIterator first, VertexPairIterator last) {
+    typedef boost::graph_traits<Graph> Traits;
+    typedef typename Traits::vertex_descriptor vertex_descriptor;
+    std::map<unsigned int, vertex_descriptor> vertices;
+
+    for (unsigned int i = 0; i < nvertices; ++i)
+        vertices[i] = add_vertex(graph);
+
+    for (; first != last; ++first) {
+        unsigned int u = *first++;
+
+        BOOST_ASSERT_MSG(first != last,
+            "there is a lonely vertex at the end of the edge list");
+
+        unsigned int v = *first;
+
+        BOOST_ASSERT_MSG(vertices.count(u) == 1 && vertices.count(v) == 1,
+            "specified a vertex over the number of vertices in the graph");
+
+        add_edge(vertices[u], vertices[v], graph);
+    }
+    BOOST_ASSERT(num_vertices(graph) == nvertices);
+}
+
+
+int main(int argc, char const* argv[]) {
+    if (argc < 2) {
+        std::cout << "usage: " << argv[0] << " num_vertices < input\n";
+        return EXIT_FAILURE;
+    }
+
+    unsigned int num_vertices = boost::lexical_cast<unsigned int>(argv[1]);
+    std::istream_iterator<unsigned int> first_vertex(std::cin), last_vertex;
+    boost::directed_graph<> graph;
+    build_graph(graph, num_vertices, first_vertex, last_vertex);
+
+    cycle_printer<std::ostream> visitor(std::cout);
+    boost::hawick_circuits(graph, visitor);
+
+    return EXIT_SUCCESS;
+}