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1 //======================================================================= |
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2 // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. |
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3 // Copyright (C) Vladimir Prus 2003 |
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4 // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek |
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5 // |
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6 // Distributed under the Boost Software License, Version 1.0. (See |
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7 // accompanying file LICENSE_1_0.txt or copy at |
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8 // http://www.boost.org/LICENSE_1_0.txt) |
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9 //======================================================================= |
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10 #ifndef BOOST_GRAPH_RANDOM_HPP |
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11 #define BOOST_GRAPH_RANDOM_HPP |
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12 |
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13 #include <boost/graph/graph_traits.hpp> |
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14 #include <boost/random/uniform_int.hpp> |
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15 #include <boost/random/variate_generator.hpp> |
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16 |
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17 #include <boost/pending/property.hpp> |
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18 #include <boost/graph/properties.hpp> |
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19 |
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20 #include <boost/graph/adjacency_list.hpp> |
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21 #include <boost/graph/copy.hpp> |
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22 #include <boost/mpl/if.hpp> |
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23 #include <boost/type_traits/is_convertible.hpp> |
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24 |
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25 #include <iostream> |
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26 |
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27 namespace boost { |
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28 |
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29 // grab a random vertex from the graph's vertex set |
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30 template <class Graph, class RandomNumGen> |
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31 typename graph_traits<Graph>::vertex_descriptor |
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32 random_vertex(Graph& g, RandomNumGen& gen) |
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33 { |
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34 if (num_vertices(g) > 1) { |
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35 #if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581)) |
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36 std::size_t n = std::random( num_vertices(g) ); |
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37 #else |
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38 uniform_int<> distrib(0, num_vertices(g)-1); |
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39 variate_generator<RandomNumGen&, uniform_int<> > rand_gen(gen, distrib); |
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40 std::size_t n = rand_gen(); |
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41 #endif |
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42 typename graph_traits<Graph>::vertex_iterator |
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43 i = vertices(g).first; |
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44 while (n-- > 0) ++i; // std::advance not VC++ portable |
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45 return *i; |
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46 } else |
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47 return *vertices(g).first; |
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48 } |
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49 |
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50 template <class Graph, class RandomNumGen> |
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51 typename graph_traits<Graph>::edge_descriptor |
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52 random_edge(Graph& g, RandomNumGen& gen) { |
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53 if (num_edges(g) > 1) { |
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54 #if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581)) |
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55 typename graph_traits<Graph>::edges_size_type |
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56 n = std::random( num_edges(g) ); |
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57 #else |
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58 uniform_int<> distrib(0, num_edges(g)-1); |
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59 variate_generator<RandomNumGen&, uniform_int<> > rand_gen(gen, distrib); |
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60 typename graph_traits<Graph>::edges_size_type |
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61 n = rand_gen(); |
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62 #endif |
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63 typename graph_traits<Graph>::edge_iterator |
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64 i = edges(g).first; |
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65 while (n-- > 0) ++i; // std::advance not VC++ portable |
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66 return *i; |
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67 } else |
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68 return *edges(g).first; |
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69 } |
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70 |
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71 namespace detail { |
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72 class dummy_property_copier { |
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73 public: |
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74 template<class V1, class V2> |
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75 void operator()(const V1&, const V2&) const {} |
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76 }; |
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77 } |
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78 |
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79 template <typename MutableGraph, class RandNumGen> |
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80 void generate_random_graph1 |
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81 (MutableGraph& g, |
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82 typename graph_traits<MutableGraph>::vertices_size_type V, |
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83 typename graph_traits<MutableGraph>::vertices_size_type E, |
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84 RandNumGen& gen, |
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85 bool allow_parallel = true, |
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86 bool self_edges = false) |
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87 { |
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88 typedef graph_traits<MutableGraph> Traits; |
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89 typedef typename Traits::vertices_size_type v_size_t; |
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90 typedef typename Traits::edges_size_type e_size_t; |
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91 typedef typename Traits::vertex_descriptor vertex_descriptor; |
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92 |
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93 // When parallel edges are not allowed, we create a new graph which |
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94 // does not allow parallel edges, construct it and copy back. |
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95 // This is not efficient if 'g' already disallow parallel edges, |
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96 // but that's task for later. |
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97 if (!allow_parallel) { |
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98 |
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99 typedef typename boost::graph_traits<MutableGraph>::directed_category dir; |
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100 typedef typename mpl::if_<is_convertible<dir, directed_tag>, |
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101 directedS, undirectedS>::type select; |
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102 adjacency_list<setS, vecS, select> g2; |
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103 generate_random_graph1(g2, V, E, gen, true, self_edges); |
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104 |
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105 copy_graph(g2, g, vertex_copy(detail::dummy_property_copier()). |
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106 edge_copy(detail::dummy_property_copier())); |
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107 |
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108 } else { |
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109 |
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110 for (v_size_t i = 0; i < V; ++i) |
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111 add_vertex(g); |
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112 |
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113 for (e_size_t j = 0; j < E; ++j) { |
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114 vertex_descriptor a = random_vertex(g, gen), b; |
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115 do { |
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116 b = random_vertex(g, gen); |
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117 } while (self_edges == false && a == b); |
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118 add_edge(a, b, g); |
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119 } |
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120 } |
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121 } |
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122 |
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123 template <typename MutableGraph, class RandNumGen> |
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124 void generate_random_graph |
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125 (MutableGraph& g, |
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126 typename graph_traits<MutableGraph>::vertices_size_type V, |
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127 typename graph_traits<MutableGraph>::vertices_size_type E, |
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128 RandNumGen& gen, |
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129 bool allow_parallel = true, |
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130 bool self_edges = false) |
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131 { |
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132 generate_random_graph1(g, V, E, gen, allow_parallel, self_edges); |
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133 } |
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134 |
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135 template <typename MutableGraph, typename RandNumGen, |
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136 typename VertexOutputIterator, typename EdgeOutputIterator> |
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137 void generate_random_graph |
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138 (MutableGraph& g, |
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139 typename graph_traits<MutableGraph>::vertices_size_type V, |
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140 typename graph_traits<MutableGraph>::vertices_size_type E, |
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141 RandNumGen& gen, |
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142 VertexOutputIterator vertex_out, |
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143 EdgeOutputIterator edge_out, |
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144 bool self_edges = false) |
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145 { |
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146 typedef graph_traits<MutableGraph> Traits; |
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147 typedef typename Traits::vertices_size_type v_size_t; |
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148 typedef typename Traits::edges_size_type e_size_t; |
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149 typedef typename Traits::vertex_descriptor vertex_t; |
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150 typedef typename Traits::edge_descriptor edge_t; |
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151 |
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152 for (v_size_t i = 0; i < V; ++i) |
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153 *vertex_out++ = add_vertex(g); |
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154 |
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155 for (e_size_t j = 0; j < E; ++j) { |
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156 vertex_t a = random_vertex(g, gen), b; |
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157 do { |
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158 b = random_vertex(g, gen); |
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159 } while (self_edges == false && a == b); |
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160 edge_t e; bool inserted; |
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161 tie(e, inserted) = add_edge(a, b, g); |
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162 if (inserted) |
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163 *edge_out++ = std::make_pair(source(e, g), target(e, g)); |
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164 } |
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165 } |
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166 |
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167 namespace detail { |
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168 |
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169 template<class Property, class G, class RandomGenerator> |
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170 void randomize_property(G& g, RandomGenerator& rg, |
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171 Property, vertex_property_tag) |
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172 { |
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173 typename property_map<G, Property>::type pm = get(Property(), g); |
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174 typename graph_traits<G>::vertex_iterator vi, ve; |
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175 for (tie(vi, ve) = vertices(g); vi != ve; ++vi) { |
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176 pm[*vi] = rg(); |
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177 } |
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178 } |
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179 |
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180 template<class Property, class G, class RandomGenerator> |
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181 void randomize_property(G& g, RandomGenerator& rg, |
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182 Property, edge_property_tag) |
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183 { |
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184 typename property_map<G, Property>::type pm = get(Property(), g); |
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185 typename graph_traits<G>::edge_iterator ei, ee; |
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186 for (tie(ei, ee) = edges(g); ei != ee; ++ei) { |
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187 pm[*ei] = rg(); |
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188 } |
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189 } |
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190 } |
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191 |
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192 template<class Property, class G, class RandomGenerator> |
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193 void randomize_property(G& g, RandomGenerator& rg) |
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194 { |
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195 detail::randomize_property |
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196 (g, rg, Property(), typename property_kind<Property>::type()); |
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197 } |
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198 |
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199 |
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200 |
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201 |
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202 } |
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203 |
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204 |
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205 #endif |