1 | // -*- c++ -*- |
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2 | #include <vector> |
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3 | #include <cstdlib> |
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4 | |
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5 | // ///\ingroup gwrappers |
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6 | ///\file |
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7 | ///\brief Graph generator functions. |
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8 | /// |
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9 | ///This file contains several graph generator functions. |
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10 | /// |
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11 | // ///\author Marton Makai |
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12 | |
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13 | namespace hugo { |
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14 | |
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15 | |
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16 | /** |
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17 | * Inicializalja a veletlenszamgeneratort. |
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18 | * Figyelem, ez nem jo igazi random szamokhoz, |
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19 | * erre ne bizzad a titkaidat! |
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20 | */ |
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21 | void random_init() |
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22 | { |
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23 | unsigned int seed = getpid(); |
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24 | seed |= seed << 15; |
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25 | seed ^= time(0); |
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26 | |
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27 | srand(seed); |
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28 | } |
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29 | |
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30 | |
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31 | /** |
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32 | * Egy veletlen int-et ad vissza 0 es m-1 kozott. |
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33 | */ |
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34 | int random(int m) |
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35 | { |
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36 | return int( double(m) * rand() / (RAND_MAX + 1.0) ); |
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37 | } |
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38 | |
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39 | |
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40 | /// Generates a random graph with n nodes and m edges. |
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41 | /// Before generating the random graph, \c g.clear() is called. |
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42 | template<typename Graph> |
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43 | void randomGraph(Graph& g, int n, int m) { |
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44 | g.clear(); |
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45 | std::vector<typename Graph::Node> nodes; |
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46 | for (int i=0; i<n; ++i) |
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47 | nodes.push_back(g.addNode()); |
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48 | for (int i=0; i<m; ++i) |
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49 | g.addEdge(nodes[random(n)], nodes[random(n)]); |
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50 | } |
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51 | |
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52 | /// Generates a random bipartite graph with a and b nodes |
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53 | /// in the color classes and m edges. |
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54 | /// According to the bipartite graph concept, the resulting |
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55 | /// graph is directed from the first class to the second one. |
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56 | /// Before generating the random graph, \c g.clear() is called. |
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57 | template<typename Graph> |
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58 | void randomBipartiteGraph(Graph& g, int a, int b, int m) { |
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59 | g.clear(); |
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60 | std::vector<typename Graph::Node> s_nodes; |
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61 | std::vector<typename Graph::Node> t_nodes; |
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62 | for (int i=0; i<a; ++i) |
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63 | ///\bug g.addNode(g.S_CLASS) would be better. |
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64 | s_nodes.push_back(g.addNode(false)); |
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65 | for (int i=0; i<b; ++i) |
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66 | ///\bug g.addNode(g.T_CLASS) would be better. |
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67 | t_nodes.push_back(g.addNode(true)); |
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68 | for (int i=0; i<m; ++i) |
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69 | g.addEdge(s_nodes[random(a)], t_nodes[random(b)]); |
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70 | } |
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71 | |
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72 | /// Generates a complete graph in the undirected sense |
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73 | /// with n nodes. |
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74 | /// Before generating the random graph, \c g.clear() is called. |
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75 | template<typename Graph> |
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76 | void completeGraph(Graph& g, int n) { |
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77 | g.clear(); |
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78 | std::vector<typename Graph::Node> nodes; |
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79 | for (int i=0; i<n; ++i) |
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80 | nodes.push_back(g.addNode()); |
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81 | for (int i=0; i<n; ++i) |
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82 | for (int j=i+1; j<n; ++j) |
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83 | g.addEdge(nodes[i], nodes[j]); |
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84 | } |
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85 | |
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86 | /// Generates a complete bidirected graph on n nodes. |
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87 | /// Before generating the random graph, \c g.clear() is called. |
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88 | template<typename Graph> |
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89 | void completeBidirectedGraph(Graph& g, int n) { |
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90 | g.clear(); |
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91 | std::vector<typename Graph::Node> nodes; |
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92 | for (int i=0; i<n; ++i) |
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93 | nodes.push_back(g.addNode()); |
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94 | for (int i=0; i<n; ++i) |
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95 | for (int j=i+1; j<n; ++j) { |
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96 | g.addEdge(nodes[i], nodes[j]); |
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97 | g.addEdge(nodes[j], nodes[i]); |
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98 | } |
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99 | } |
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100 | |
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101 | /// Generates a complete bipartite graph with a and b nodes |
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102 | /// in the color classes. |
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103 | /// Before generating the random graph, \c g.clear() is called. |
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104 | template<typename Graph> |
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105 | void completeBipartiteGraph(Graph& g, int a, int b) { |
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106 | g.clear(); |
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107 | std::vector<typename Graph::Node> s_nodes; |
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108 | std::vector<typename Graph::Node> t_nodes; |
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109 | for (int i=0; i<a; ++i) |
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110 | ///\bug g.addNode(g.S_CLASS) would be better. |
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111 | s_nodes.push_back(g.addNode(false)); |
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112 | for (int i=0; i<b; ++i) |
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113 | ///\bug g.addNode(g.T_CLASS) would be better. |
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114 | t_nodes.push_back(g.addNode(true)); |
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115 | for (int i=0; i<a; ++i) |
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116 | for (int j=0; j<b; ++j) |
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117 | g.addEdge(s_nodes[i], t_nodes[j]); |
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118 | } |
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119 | |
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120 | } //namespace hugo |
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