1 | /* |
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2 | * Shooting* Shortest path algorithm for PostgreSQL |
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3 | * |
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4 | * Copyright (c) 2007 Anton A. Patrushev, Orkney, Inc. |
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5 | * |
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6 | * This program is free software; you can redistribute it and/or modify |
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7 | * it under the terms of the GNU General Public License as published by |
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8 | * the Free Software Foundation; either version 2 of the License, or |
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9 | * (at your option) any later version. |
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10 | * |
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11 | * This program is distributed in the hope that it will be useful, |
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12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | * GNU General Public License for more details. |
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15 | * |
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16 | * You should have received a copy of the GNU General Public License |
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17 | * along with this program; if not, write to the Free Software |
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18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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19 | * |
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20 | */ |
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21 | |
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22 | #include <boost/config.hpp> |
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23 | #include <iostream> |
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24 | #include <fstream> |
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25 | |
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26 | #include <boost/graph/graph_traits.hpp> |
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27 | #include <boost/graph/adjacency_list.hpp> |
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28 | #include <boost/vector_property_map.hpp> |
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29 | #include <shooting_star_search.hpp> |
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30 | |
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31 | #include "shooting_star.h" |
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32 | |
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33 | #include <math.h> // for sqrt |
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34 | |
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35 | using namespace std; |
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36 | using namespace boost; |
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37 | |
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38 | // Maximal number of nodes in the path (to avoid infinite loops) |
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39 | #define MAX_NODES 1000000 |
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40 | |
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41 | struct Edge |
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42 | { |
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43 | int id; |
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44 | int source; |
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45 | int target; |
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46 | float8 cost; |
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47 | float8 distance; |
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48 | float8 rank; |
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49 | std::map< int, std::pair<float8, std::vector<int> >, std::less<int> > adjacent_edges; |
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50 | |
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51 | std::vector< int > history; |
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52 | |
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53 | default_color_type color; |
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54 | |
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55 | std::size_t index; |
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56 | |
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57 | adjacency_list_traits<vecS, vecS, directedS>::edge_descriptor predecessor; |
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58 | }; |
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59 | |
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60 | struct Vertex |
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61 | { |
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62 | int id; |
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63 | float8 x; |
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64 | float8 y; |
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65 | |
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66 | default_color_type color; |
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67 | |
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68 | float8 cost; |
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69 | |
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70 | }; |
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71 | |
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72 | |
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73 | struct found_goal {}; // exception for termination |
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74 | |
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75 | // visitor that terminates when we find the goal |
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76 | template <class Edge> |
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77 | class shooting_star_goal_visitor : public boost::default_shooting_star_visitor |
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78 | { |
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79 | public: |
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80 | shooting_star_goal_visitor(Edge goal) : m_goal(goal) {} |
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81 | |
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82 | template <class Graph> |
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83 | void examine_edge(Edge e, Graph& g) { |
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84 | if(g[e].id == g[m_goal].id) |
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85 | throw found_goal(); |
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86 | } |
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87 | template <class Graph> |
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88 | void finish_edge(Edge e, Graph& g) {} |
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89 | private: |
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90 | Edge m_goal; |
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91 | }; |
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92 | |
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93 | |
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94 | template <class Graph, class CostType> |
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95 | class distance_heuristic : public astar_heuristic<Graph, CostType> |
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96 | { |
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97 | public: |
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98 | typedef typename graph_traits<Graph>::edge_descriptor Edge; |
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99 | distance_heuristic(Graph& g, Edge goal):m_g(g), m_goal(goal){} |
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100 | CostType operator()(Edge e) |
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101 | { |
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102 | CostType dx = m_g[target(m_goal, m_g)].x - m_g[target(e, m_g)].x; |
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103 | CostType dy = m_g[target(m_goal, m_g)].y - m_g[target(e, m_g)].y; |
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104 | //You can choose any heuristical function from below |
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105 | //return ::max(dx, dy); |
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106 | //return ::sqrt(dx * dx + dy * dy)/2; |
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107 | //return 0; |
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108 | return (::fabs(dx)+::fabs(dy))/2; |
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109 | } |
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110 | private: |
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111 | Graph& m_g; |
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112 | Edge m_goal; |
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113 | }; |
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114 | |
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115 | |
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116 | template <class G, class E> |
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117 | static void |
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118 | graph_add_edge(G &graph, int id, int source, int target, |
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119 | float8 cost, float8 s_x, float8 s_y, float8 t_x, float8 t_y, |
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120 | std::map< int, std::pair<float8, vector<int> >, std::less<int> > adjacent_edges) |
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121 | { |
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122 | |
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123 | E e; |
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124 | bool inserted; |
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125 | |
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126 | if (cost < 0) // edges are not inserted in the graph if cost is negative |
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127 | return; |
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128 | |
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129 | tie(e, inserted) = add_edge(source, target, graph); |
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130 | |
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131 | graph[e].cost = cost; |
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132 | graph[e].id = id; |
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133 | |
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134 | // put(edge_index, graph, graph[e], id); |
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135 | |
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136 | graph[e].source = source; |
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137 | graph[e].target = target; |
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138 | |
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139 | graph[e].adjacent_edges = adjacent_edges; |
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140 | |
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141 | typedef typename graph_traits<G>::vertex_descriptor Vertex; |
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142 | Vertex s = vertex(source, graph); |
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143 | Vertex t = vertex(target, graph); |
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144 | |
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145 | graph[s].id=source; |
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146 | graph[t].id=target; |
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147 | |
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148 | graph[s].x=s_x; |
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149 | graph[s].y=s_y; |
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150 | graph[t].x=t_x; |
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151 | graph[t].y=t_y; |
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152 | |
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153 | } |
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154 | |
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155 | int |
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156 | boost_shooting_star(edge_shooting_star_t *edges_array, unsigned int count, |
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157 | int source_edge_id, int target_edge_id, |
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158 | bool directed, bool has_reverse_cost, |
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159 | path_element_t **path, int *path_count, char **err_msg, int e_max_id) |
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160 | { |
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161 | |
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162 | typedef adjacency_list<vecS, vecS, directedS, Vertex, Edge> graph_t; |
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163 | |
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164 | typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor; |
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165 | typedef graph_traits < graph_t >::edge_descriptor edge_descriptor; |
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166 | |
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167 | const unsigned int num_nodes = /*1*/count*2; |
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168 | |
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169 | int z; |
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170 | int src, trg, offset; |
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171 | |
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172 | graph_t graph(num_nodes); |
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173 | |
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174 | std::map< int, std::pair<float8, vector<int> >, std::less<int> > adjacent_edges; |
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175 | |
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176 | std::map< int, int, std::less<int> > vertices; |
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177 | |
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178 | offset = 0; |
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179 | |
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180 | for (std::size_t j = 0; j < count; ++j) |
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181 | { |
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182 | //Vertex ids renumbering moved here |
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183 | |
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184 | src = edges_array[j].source; |
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185 | trg = edges_array[j].target; |
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186 | |
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187 | if(vertices[src]==NULL) |
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188 | //if (vertices.find(edges_array[j].source) == vertices.end()) |
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189 | { |
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190 | vertices[src]=j+offset; |
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191 | edges_array[j].source=j+offset; |
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192 | |
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193 | } |
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194 | else |
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195 | { |
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196 | edges_array[j].source=vertices[src]; |
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197 | } |
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198 | |
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199 | if(vertices[trg]==NULL) |
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200 | //if (vertices.find(edges_array[j].target) == vertices.end()) |
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201 | { |
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202 | offset++; |
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203 | |
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204 | vertices[trg]=j+offset; |
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205 | edges_array[j].target=j+offset; |
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206 | } |
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207 | else |
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208 | { |
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209 | edges_array[j].target=vertices[trg]; |
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210 | } |
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211 | |
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212 | adjacent_edges[edges_array[j].id].first = edges_array[j].to_cost; |
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213 | |
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214 | for(z=0; z<MAX_RULE_LENGTH;++z) |
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215 | { |
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216 | if(edges_array[j].rule[z] > 0) |
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217 | { |
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218 | adjacent_edges[edges_array[j].id].second.push_back(edges_array[j].rule[z]); |
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219 | } |
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220 | } |
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221 | |
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222 | if((j < count-1 && edges_array[j].id != edges_array[j+1].id)||(j==count-1)) |
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223 | { |
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224 | graph_add_edge<graph_t, edge_descriptor>(graph, |
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225 | edges_array[j].id, edges_array[j].source, |
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226 | edges_array[j].target, edges_array[j].cost, |
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227 | edges_array[j].s_x, edges_array[j].s_y, |
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228 | edges_array[j].t_x, edges_array[j].t_y, adjacent_edges); |
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229 | |
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230 | if (!directed || (directed && has_reverse_cost)) |
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231 | { |
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232 | float8 cost; |
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233 | |
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234 | if (has_reverse_cost) |
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235 | { |
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236 | cost = edges_array[j].reverse_cost; |
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237 | } |
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238 | else |
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239 | { |
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240 | cost = edges_array[j].cost; |
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241 | } |
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242 | |
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243 | graph_add_edge<graph_t, edge_descriptor>(graph, |
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244 | edges_array[j].id+e_max_id, edges_array[j].target, |
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245 | edges_array[j].source, cost, |
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246 | edges_array[j].s_x, edges_array[j].s_y, |
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247 | edges_array[j].t_x, edges_array[j].t_y, adjacent_edges); |
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248 | } |
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249 | |
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250 | adjacent_edges.clear(); |
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251 | |
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252 | } |
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253 | } |
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254 | |
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255 | std::map< int, edge_descriptor, std::less<int> > predecessors; |
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256 | |
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257 | edge_descriptor source_edge; |
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258 | edge_descriptor target_edge; |
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259 | |
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260 | bool source_found = false, target_found = false; |
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261 | |
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262 | graph_traits<graph_t>::edge_iterator ei, ei_end; |
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263 | int index; |
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264 | |
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265 | index = 1; |
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266 | |
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267 | for(tie(ei, ei_end) = edges(graph); ei != ei_end; ++ei, ++index) |
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268 | graph[*ei].index = index; |
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269 | |
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270 | for(tie(ei, ei_end) = edges(graph); ei != ei_end; ++ei) |
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271 | { |
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272 | if(graph[*ei].id == source_edge_id) |
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273 | { |
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274 | source_edge = *ei; |
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275 | source_found = true; |
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276 | break; |
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277 | } |
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278 | } |
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279 | |
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280 | if (!source_found) |
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281 | { |
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282 | *err_msg = "Source edge not found"; |
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283 | return -1; |
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284 | } |
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285 | |
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286 | for(tie(ei, ei_end) = edges(graph); ei != ei_end; ++ei) |
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287 | { |
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288 | if(graph[*ei].id == target_edge_id) |
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289 | { |
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290 | target_edge = *ei; |
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291 | target_found = true; |
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292 | break; |
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293 | } |
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294 | } |
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295 | |
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296 | if (!target_found) |
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297 | { |
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298 | *err_msg = "Target edge not found"; |
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299 | return -1; |
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300 | } |
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301 | |
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302 | std::vector<float8> distances(num_edges(graph)); |
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303 | |
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304 | std::vector<default_color_type> edge_colors(num_edges(graph), color_traits<default_color_type>::white()); |
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305 | |
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306 | property_map<graph_t, std::vector< int > Edge::*>::type history = get(&Edge::history, graph); |
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307 | |
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308 | property_map<graph_t, std::size_t Edge::*>::type edge_index = get(&Edge::index, graph); |
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309 | |
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310 | property_map<graph_t, float8 Edge::*>::type rank = get(&Edge::rank, graph); |
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311 | property_map<graph_t, float8 Edge::*>::type distance = get(&Edge::distance, graph); |
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312 | |
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313 | try |
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314 | { |
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315 | shooting_star_search |
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316 | (graph, source_edge, |
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317 | distance_heuristic<graph_t, float>(graph, target_edge), |
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318 | weight_map(get(&Edge::cost, graph)). |
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319 | weight_map2(get(&Edge::adjacent_edges, graph)). |
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320 | vertex_color_map(get(&Vertex::color, graph)). |
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321 | edge_color_map(get(&Edge::color, graph)). |
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322 | visitor(shooting_star_goal_visitor<edge_descriptor>(target_edge)), |
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323 | edge_index, |
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324 | distance, rank, |
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325 | history, |
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326 | predecessors, e_max_id |
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327 | ); |
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328 | |
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329 | } |
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330 | catch(found_goal fg) { |
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331 | |
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332 | vector<edge_descriptor> path_vect; |
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333 | int max = MAX_NODES; |
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334 | |
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335 | path_vect.push_back(target_edge); |
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336 | |
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337 | while (target_edge != source_edge) |
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338 | { |
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339 | if ((target_edge == predecessors[graph[target_edge].id]) && (predecessors[graph[target_edge].id] != source_edge)) |
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340 | { |
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341 | *err_msg = "No path found"; |
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342 | return -1; |
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343 | |
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344 | } |
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345 | |
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346 | target_edge = predecessors[graph[target_edge].id]; |
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347 | |
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348 | if(target_edge == predecessors[graph[target_edge].id] ) |
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349 | continue; |
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350 | |
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351 | path_vect.push_back(target_edge); |
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352 | |
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353 | if (!max--) |
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354 | { |
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355 | *err_msg = "Overflow"; |
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356 | return -1; |
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357 | } |
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358 | } |
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359 | |
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360 | *path = (path_element_t *) malloc(sizeof(path_element_t) * |
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361 | (path_vect.size() + 1)); |
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362 | *path_count = path_vect.size(); |
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363 | |
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364 | for(int i = path_vect.size() - 1, j = 0; i >= 0; i--, j++) |
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365 | { |
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366 | graph_traits < graph_t >::edge_descriptor e; |
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367 | |
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368 | e = path_vect.at(i); |
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369 | |
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370 | if(graph[e].id > e_max_id) |
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371 | graph[e].id -= e_max_id; |
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372 | |
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373 | (*path)[j].edge_id = graph[e].id; |
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374 | (*path)[j].cost = graph[e].cost; |
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375 | (*path)[j].vertex_id = source(e, graph); |
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376 | } |
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377 | |
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378 | return EXIT_SUCCESS; |
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379 | } |
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380 | |
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381 | } |
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382 | |
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