vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/graph/random.hpp

266 lines
9.3 KiB
C++

//=======================================================================
// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
// Copyright (C) Vladimir Prus 2003
// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
//
// 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)
//=======================================================================
#ifndef BOOST_GRAPH_RANDOM_HPP
#define BOOST_GRAPH_RANDOM_HPP
#include <boost/graph/graph_traits.hpp>
#include <boost/random/uniform_int.hpp>
#include <boost/random/uniform_real.hpp>
#include <boost/random/variate_generator.hpp>
#include <boost/pending/property.hpp>
#include <boost/graph/properties.hpp>
#include <boost/graph/iteration_macros.hpp>
#include <boost/next_prior.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/copy.hpp>
#include <boost/mpl/if.hpp>
#include <boost/type_traits/is_convertible.hpp>
#include <iostream>
#include <boost/assert.hpp>
namespace boost {
// grab a random vertex from the graph's vertex set
template <class Graph, class RandomNumGen>
typename graph_traits<Graph>::vertex_descriptor
random_vertex(Graph& g, RandomNumGen& gen)
{
if (num_vertices(g) > 1) {
#if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581))
std::size_t n = std::random( num_vertices(g) );
#else
uniform_int<> distrib(0, num_vertices(g)-1);
variate_generator<RandomNumGen&, uniform_int<> > rand_gen(gen, distrib);
std::size_t n = rand_gen();
#endif
typename graph_traits<Graph>::vertex_iterator
i = vertices(g).first;
return *(boost::next(i, n));
} else
return *vertices(g).first;
}
template <class Graph, class RandomNumGen>
typename graph_traits<Graph>::edge_descriptor
random_edge(Graph& g, RandomNumGen& gen) {
if (num_edges(g) > 1) {
#if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581))
typename graph_traits<Graph>::edges_size_type
n = std::random( num_edges(g) );
#else
uniform_int<> distrib(0, num_edges(g)-1);
variate_generator<RandomNumGen&, uniform_int<> > rand_gen(gen, distrib);
typename graph_traits<Graph>::edges_size_type
n = rand_gen();
#endif
typename graph_traits<Graph>::edge_iterator
i = edges(g).first;
return *(boost::next(i, n));
} else
return *edges(g).first;
}
template <typename Graph, typename RandomNumGen>
typename graph_traits<Graph>::edge_descriptor
random_out_edge(Graph& g, typename graph_traits<Graph>::vertex_descriptor src, RandomNumGen& gen) {
typedef typename graph_traits<Graph>::degree_size_type degree_size_type;
typedef boost::uniform_int<degree_size_type> ui_type;
ui_type ui(0, out_degree(src, g) - 1);
boost::variate_generator<RandomNumGen&, ui_type>
variate(gen, ui);
typename graph_traits<Graph>::out_edge_iterator it = out_edges(src, g).first;
std::advance(it, variate());
return *it;
}
template <typename Graph, typename WeightMap, typename RandomNumGen>
typename graph_traits<Graph>::edge_descriptor
weighted_random_out_edge(Graph& g, typename graph_traits<Graph>::vertex_descriptor src, WeightMap weight, RandomNumGen& gen) {
typedef typename property_traits<WeightMap>::value_type weight_type;
weight_type weight_sum(0);
BGL_FORALL_OUTEDGES_T(src, e, g, Graph) {weight_sum += get(weight, e);}
typedef boost::uniform_real<> ur_type;
ur_type ur(0, weight_sum);
boost::variate_generator<RandomNumGen&, ur_type>
variate(gen, ur);
weight_type chosen_weight = variate();
BGL_FORALL_OUTEDGES_T(src, e, g, Graph) {
weight_type w = get(weight, e);
if (chosen_weight < w) {
return e;
} else {
chosen_weight -= w;
}
}
BOOST_ASSERT (false); // Should not get here
return typename graph_traits<Graph>::edge_descriptor();
}
namespace detail {
class dummy_property_copier {
public:
template<class V1, class V2>
void operator()(const V1&, const V2&) const {}
};
}
template <typename MutableGraph, class RandNumGen>
void generate_random_graph1
(MutableGraph& g,
typename graph_traits<MutableGraph>::vertices_size_type V,
typename graph_traits<MutableGraph>::vertices_size_type E,
RandNumGen& gen,
bool allow_parallel = true,
bool self_edges = false)
{
typedef graph_traits<MutableGraph> Traits;
typedef typename Traits::edge_descriptor edge_t;
typedef typename Traits::vertices_size_type v_size_t;
typedef typename Traits::edges_size_type e_size_t;
typedef typename Traits::vertex_descriptor vertex_descriptor;
// When parallel edges are not allowed, we create a new graph which
// does not allow parallel edges, construct it and copy back.
// This is not efficient if 'g' already disallow parallel edges,
// but that's task for later.
if (!allow_parallel) {
typedef typename boost::graph_traits<MutableGraph>::directed_category dir;
typedef typename mpl::if_<is_convertible<dir, directed_tag>,
directedS, undirectedS>::type select;
adjacency_list<setS, vecS, select> g2;
generate_random_graph1(g2, V, E, gen, true, self_edges);
copy_graph(g2, g, vertex_copy(detail::dummy_property_copier()).
edge_copy(detail::dummy_property_copier()));
} else {
for (v_size_t i = 0; i < V; ++i)
add_vertex(g);
e_size_t not_inserted_counter = 0; /* Number of edge insertion failures */
e_size_t num_vertices_squared = num_vertices(g) * num_vertices(g);
for (e_size_t j = 0; j < E; /* Increment in body */) {
vertex_descriptor a = random_vertex(g, gen), b;
do {
b = random_vertex(g, gen);
} while (self_edges == false && a == b);
edge_t e; bool inserted;
boost::tie(e, inserted) = add_edge(a, b, g);
if (inserted) {
++j;
} else {
++not_inserted_counter;
}
if (not_inserted_counter >= num_vertices_squared) {
return; /* Rather than looping forever on complete graph */
}
}
}
}
template <typename MutableGraph, class RandNumGen>
void generate_random_graph
(MutableGraph& g,
typename graph_traits<MutableGraph>::vertices_size_type V,
typename graph_traits<MutableGraph>::vertices_size_type E,
RandNumGen& gen,
bool allow_parallel = true,
bool self_edges = false)
{
generate_random_graph1(g, V, E, gen, allow_parallel, self_edges);
}
template <typename MutableGraph, typename RandNumGen,
typename VertexOutputIterator, typename EdgeOutputIterator>
void generate_random_graph
(MutableGraph& g,
typename graph_traits<MutableGraph>::vertices_size_type V,
typename graph_traits<MutableGraph>::vertices_size_type E,
RandNumGen& gen,
VertexOutputIterator vertex_out,
EdgeOutputIterator edge_out,
bool self_edges = false)
{
typedef graph_traits<MutableGraph> Traits;
typedef typename Traits::vertices_size_type v_size_t;
typedef typename Traits::edges_size_type e_size_t;
typedef typename Traits::vertex_descriptor vertex_t;
typedef typename Traits::edge_descriptor edge_t;
for (v_size_t i = 0; i < V; ++i)
*vertex_out++ = add_vertex(g);
e_size_t not_inserted_counter = 0; /* Number of edge insertion failures */
e_size_t num_vertices_squared = num_vertices(g) * num_vertices(g);
for (e_size_t j = 0; j < E; /* Increment in body */) {
vertex_t a = random_vertex(g, gen), b;
do {
b = random_vertex(g, gen);
} while (self_edges == false && a == b);
edge_t e; bool inserted;
boost::tie(e, inserted) = add_edge(a, b, g);
if (inserted) {
*edge_out++ = std::make_pair(source(e, g), target(e, g));
++j;
} else {
++not_inserted_counter;
}
if (not_inserted_counter >= num_vertices_squared) {
return; /* Rather than looping forever on complete graph */
}
}
}
namespace detail {
template<class Property, class G, class RandomGenerator>
void randomize_property(G& g, RandomGenerator& rg,
Property, vertex_property_tag)
{
typename property_map<G, Property>::type pm = get(Property(), g);
typename graph_traits<G>::vertex_iterator vi, ve;
for (boost::tie(vi, ve) = vertices(g); vi != ve; ++vi) {
pm[*vi] = rg();
}
}
template<class Property, class G, class RandomGenerator>
void randomize_property(G& g, RandomGenerator& rg,
Property, edge_property_tag)
{
typename property_map<G, Property>::type pm = get(Property(), g);
typename graph_traits<G>::edge_iterator ei, ee;
for (boost::tie(ei, ee) = edges(g); ei != ee; ++ei) {
pm[*ei] = rg();
}
}
}
template<class Property, class G, class RandomGenerator>
void randomize_property(G& g, RandomGenerator& rg)
{
detail::randomize_property
(g, rg, Property(), typename property_kind<Property>::type());
}
}
#include <boost/graph/iteration_macros_undef.hpp>
#endif