sl@0: //=======================================================================
sl@0: // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
sl@0: // Copyright (C) Vladimir Prus 2003
sl@0: // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
sl@0: //
sl@0: // Distributed under the Boost Software License, Version 1.0. (See
sl@0: // accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: //=======================================================================
sl@0: #ifndef BOOST_GRAPH_RANDOM_HPP
sl@0: #define BOOST_GRAPH_RANDOM_HPP
sl@0: 
sl@0: #include <boost/graph/graph_traits.hpp>
sl@0: #include <boost/random/uniform_int.hpp>
sl@0: #include <boost/random/variate_generator.hpp>
sl@0: 
sl@0: #include <boost/pending/property.hpp>
sl@0: #include <boost/graph/properties.hpp>
sl@0: 
sl@0: #include <boost/graph/adjacency_list.hpp>
sl@0: #include <boost/graph/copy.hpp>
sl@0: #include <boost/mpl/if.hpp>
sl@0: #include <boost/type_traits/is_convertible.hpp>
sl@0: 
sl@0: #include <iostream>
sl@0: 
sl@0: namespace boost {
sl@0: 
sl@0:   // grab a random vertex from the graph's vertex set
sl@0:   template <class Graph, class RandomNumGen>
sl@0:   typename graph_traits<Graph>::vertex_descriptor
sl@0:   random_vertex(Graph& g, RandomNumGen& gen)
sl@0:   {
sl@0:     if (num_vertices(g) > 1) {
sl@0:     #if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581))
sl@0:       std::size_t n = std::random( num_vertices(g) );
sl@0:     #else
sl@0:       uniform_int<> distrib(0, num_vertices(g)-1);
sl@0:       variate_generator<RandomNumGen&, uniform_int<> > rand_gen(gen, distrib);
sl@0:       std::size_t n = rand_gen();
sl@0:     #endif
sl@0:       typename graph_traits<Graph>::vertex_iterator
sl@0:         i = vertices(g).first;
sl@0:       while (n-- > 0) ++i; // std::advance not VC++ portable
sl@0:       return *i;
sl@0:     } else
sl@0:       return *vertices(g).first;
sl@0:   }
sl@0: 
sl@0:   template <class Graph, class RandomNumGen>
sl@0:   typename graph_traits<Graph>::edge_descriptor
sl@0:   random_edge(Graph& g, RandomNumGen& gen) {
sl@0:     if (num_edges(g) > 1) {
sl@0:     #if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581))
sl@0:       typename graph_traits<Graph>::edges_size_type
sl@0:         n = std::random( num_edges(g) );
sl@0:     #else
sl@0:       uniform_int<> distrib(0, num_edges(g)-1);
sl@0:       variate_generator<RandomNumGen&, uniform_int<> > rand_gen(gen, distrib);
sl@0:       typename graph_traits<Graph>::edges_size_type
sl@0:         n = rand_gen();
sl@0:     #endif
sl@0:       typename graph_traits<Graph>::edge_iterator
sl@0:         i = edges(g).first;
sl@0:       while (n-- > 0) ++i; // std::advance not VC++ portable
sl@0:       return *i;
sl@0:     } else
sl@0:       return *edges(g).first;
sl@0:   }
sl@0: 
sl@0:   namespace detail {
sl@0:     class dummy_property_copier {
sl@0:     public:
sl@0:       template<class V1, class V2>
sl@0:       void operator()(const V1&, const V2&) const {}
sl@0:     };
sl@0:   }
sl@0: 
sl@0:   template <typename MutableGraph, class RandNumGen>
sl@0:   void generate_random_graph1
sl@0:     (MutableGraph& g,
sl@0:      typename graph_traits<MutableGraph>::vertices_size_type V,
sl@0:      typename graph_traits<MutableGraph>::vertices_size_type E,
sl@0:      RandNumGen& gen,
sl@0:      bool allow_parallel = true,
sl@0:      bool self_edges = false)
sl@0:   {
sl@0:     typedef graph_traits<MutableGraph> Traits;
sl@0:     typedef typename Traits::vertices_size_type v_size_t;
sl@0:     typedef typename Traits::edges_size_type e_size_t;
sl@0:     typedef typename Traits::vertex_descriptor vertex_descriptor;
sl@0: 
sl@0:     // When parallel edges are not allowed, we create a new graph which
sl@0:     // does not allow parallel edges, construct it and copy back.
sl@0:     // This is not efficient if 'g' already disallow parallel edges,
sl@0:     // but that's task for later.
sl@0:     if (!allow_parallel) {
sl@0: 
sl@0:       typedef typename boost::graph_traits<MutableGraph>::directed_category dir;
sl@0:       typedef typename mpl::if_<is_convertible<dir, directed_tag>,
sl@0:           directedS, undirectedS>::type select;
sl@0:       adjacency_list<setS, vecS, select> g2;
sl@0:       generate_random_graph1(g2, V, E, gen, true, self_edges);
sl@0: 
sl@0:       copy_graph(g2, g, vertex_copy(detail::dummy_property_copier()).
sl@0:                         edge_copy(detail::dummy_property_copier()));
sl@0: 
sl@0:     } else {
sl@0: 
sl@0:       for (v_size_t i = 0; i < V; ++i)
sl@0:         add_vertex(g);
sl@0: 
sl@0:       for (e_size_t j = 0; j < E; ++j) {
sl@0:         vertex_descriptor a = random_vertex(g, gen), b;
sl@0:         do {
sl@0:           b = random_vertex(g, gen);
sl@0:         } while (self_edges == false && a == b);
sl@0:         add_edge(a, b, g);
sl@0:       }
sl@0:     }
sl@0:   }
sl@0: 
sl@0:   template <typename MutableGraph, class RandNumGen>
sl@0:   void generate_random_graph
sl@0:     (MutableGraph& g,
sl@0:      typename graph_traits<MutableGraph>::vertices_size_type V,
sl@0:      typename graph_traits<MutableGraph>::vertices_size_type E,
sl@0:      RandNumGen& gen,
sl@0:      bool allow_parallel = true,
sl@0:      bool self_edges = false)
sl@0:   {
sl@0:       generate_random_graph1(g, V, E, gen, allow_parallel, self_edges);
sl@0:   }
sl@0: 
sl@0:   template <typename MutableGraph, typename RandNumGen,
sl@0:             typename VertexOutputIterator, typename EdgeOutputIterator>
sl@0:   void generate_random_graph
sl@0:     (MutableGraph& g,
sl@0:      typename graph_traits<MutableGraph>::vertices_size_type V,
sl@0:      typename graph_traits<MutableGraph>::vertices_size_type E,
sl@0:      RandNumGen& gen,
sl@0:      VertexOutputIterator vertex_out,
sl@0:      EdgeOutputIterator edge_out,
sl@0:      bool self_edges = false)
sl@0:   {
sl@0:     typedef graph_traits<MutableGraph> Traits;
sl@0:     typedef typename Traits::vertices_size_type v_size_t;
sl@0:     typedef typename Traits::edges_size_type e_size_t;
sl@0:     typedef typename Traits::vertex_descriptor vertex_t;
sl@0:     typedef typename Traits::edge_descriptor edge_t;
sl@0: 
sl@0:     for (v_size_t i = 0; i < V; ++i)
sl@0:       *vertex_out++ = add_vertex(g);
sl@0: 
sl@0:     for (e_size_t j = 0; j < E; ++j) {
sl@0:       vertex_t a = random_vertex(g, gen), b;
sl@0:       do {
sl@0:         b = random_vertex(g, gen);
sl@0:       } while (self_edges == false && a == b);
sl@0:       edge_t e; bool inserted;
sl@0:       tie(e, inserted) = add_edge(a, b, g);
sl@0:       if (inserted)
sl@0:         *edge_out++ = std::make_pair(source(e, g), target(e, g));
sl@0:     }
sl@0:   }
sl@0: 
sl@0:   namespace detail {
sl@0: 
sl@0:     template<class Property, class G, class RandomGenerator>
sl@0:     void randomize_property(G& g, RandomGenerator& rg,
sl@0:                             Property, vertex_property_tag)
sl@0:     {
sl@0:       typename property_map<G, Property>::type pm = get(Property(), g);
sl@0:       typename graph_traits<G>::vertex_iterator vi, ve;
sl@0:       for (tie(vi, ve) = vertices(g); vi != ve; ++vi) {
sl@0:         pm[*vi] = rg();
sl@0:       }
sl@0:     }
sl@0: 
sl@0:     template<class Property, class G, class RandomGenerator>
sl@0:     void randomize_property(G& g, RandomGenerator& rg,
sl@0:                             Property, edge_property_tag)
sl@0:     {
sl@0:       typename property_map<G, Property>::type pm = get(Property(), g);
sl@0:       typename graph_traits<G>::edge_iterator ei, ee;
sl@0:       for (tie(ei, ee) = edges(g); ei != ee; ++ei) {
sl@0:         pm[*ei] = rg();
sl@0:       }
sl@0:     }
sl@0:   }
sl@0: 
sl@0:   template<class Property, class G, class RandomGenerator>
sl@0:   void randomize_property(G& g, RandomGenerator& rg)
sl@0:   {
sl@0:     detail::randomize_property
sl@0:         (g, rg, Property(), typename property_kind<Property>::type());
sl@0:   }
sl@0: 
sl@0: 
sl@0: 
sl@0:   
sl@0: }
sl@0: 
sl@0: 
sl@0: #endif