1 | // -*- c++ -*- // |
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2 | |
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3 | /** |
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4 | @defgroup paths Path Structures |
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5 | @ingroup datas |
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6 | \brief Path structures implemented in LEMON. |
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7 | |
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8 | LEMON provides flexible data structures |
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9 | to work with paths. |
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10 | |
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11 | All of them have the same interface, especially they can be built or extended |
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12 | using a standard Builder subclass. This make is easy to have e.g. the Dijkstra |
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13 | algorithm to store its result in any kind of path structure. |
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14 | |
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15 | \sa lemon::concept::Path |
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16 | |
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17 | */ |
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18 | |
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19 | ///\ingroup paths |
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20 | ///\file |
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21 | ///\brief Classes for representing paths in graphs. |
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22 | |
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23 | #ifndef LEMON_PATH_H |
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24 | #define LEMON_PATH_H |
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25 | |
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26 | #include <deque> |
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27 | #include <vector> |
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28 | #include <algorithm> |
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29 | |
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30 | #include <lemon/invalid.h> |
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31 | #include <lemon/error.h> |
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32 | #include <debug.h> |
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33 | |
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34 | namespace lemon { |
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35 | |
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36 | /// \addtogroup paths |
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37 | /// @{ |
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38 | |
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39 | |
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40 | //! \brief A structure for representing directed paths in a graph. |
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41 | //! |
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42 | //! A structure for representing directed path in a graph. |
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43 | //! \param Graph The graph type in which the path is. |
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44 | //! \param DM DebugMode, defaults to DefaultDebugMode. |
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45 | //! |
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46 | //! In a sense, the path can be treated as a graph, for is has \c NodeIt |
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47 | //! and \c EdgeIt with the same usage. These types converts to the \c Node |
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48 | //! and \c Edge of the original graph. |
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49 | //! |
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50 | //! \todo Thoroughfully check all the range and consistency tests. |
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51 | template<typename Graph, typename DM = DefaultDebugMode> |
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52 | class DirPath { |
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53 | public: |
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54 | /// Edge type of the underlying graph. |
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55 | typedef typename Graph::Edge GraphEdge; |
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56 | /// Node type of the underlying graph. |
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57 | typedef typename Graph::Node GraphNode; |
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58 | class NodeIt; |
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59 | class EdgeIt; |
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60 | |
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61 | protected: |
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62 | const Graph *gr; |
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63 | typedef std::vector<GraphEdge> Container; |
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64 | Container edges; |
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65 | |
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66 | public: |
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67 | |
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68 | /// \param _G The graph in which the path is. |
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69 | /// |
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70 | DirPath(const Graph &_G) : gr(&_G) {} |
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71 | |
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72 | /// \brief Subpath constructor. |
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73 | /// |
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74 | /// Subpath defined by two nodes. |
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75 | /// \warning It is an error if the two edges are not in order! |
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76 | DirPath(const DirPath &P, const NodeIt &a, const NodeIt &b) { |
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77 | if( DM::range_check && (!a.valid() || !b.valid) ) { |
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78 | // FIXME: this check should be more elaborate... |
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79 | fault("DirPath, subpath ctor: invalid bounding nodes"); |
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80 | } |
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81 | gr = P.gr; |
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82 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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83 | } |
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84 | |
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85 | /// \brief Subpath constructor. |
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86 | /// |
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87 | /// Subpath defined by two edges. Contains edges in [a,b) |
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88 | /// \warning It is an error if the two edges are not in order! |
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89 | DirPath(const DirPath &P, const EdgeIt &a, const EdgeIt &b) { |
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90 | if( DM::range_check && (!a.valid() || !b.valid) ) { |
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91 | // FIXME: this check should be more elaborate... |
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92 | fault("DirPath, subpath ctor: invalid bounding nodes"); |
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93 | } |
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94 | gr = P.gr; |
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95 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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96 | } |
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97 | |
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98 | /// Length of the path. |
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99 | size_t length() const { return edges.size(); } |
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100 | /// Returns whether the path is empty. |
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101 | bool empty() const { return edges.empty(); } |
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102 | |
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103 | /// Resets the path to an empty path. |
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104 | void clear() { edges.clear(); } |
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105 | |
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106 | /// \brief Starting point of the path. |
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107 | /// |
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108 | /// Starting point of the path. |
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109 | /// Returns INVALID if the path is empty. |
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110 | GraphNode from() const { |
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111 | return empty() ? INVALID : gr->tail(edges[0]); |
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112 | } |
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113 | /// \brief End point of the path. |
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114 | /// |
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115 | /// End point of the path. |
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116 | /// Returns INVALID if the path is empty. |
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117 | GraphNode to() const { |
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118 | return empty() ? INVALID : gr->head(edges[length()-1]); |
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119 | } |
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120 | |
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121 | /// \brief Initializes node or edge iterator to point to the first |
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122 | /// node or edge. |
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123 | /// |
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124 | /// \sa nth |
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125 | template<typename It> |
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126 | It& first(It &i) const { return i=It(*this); } |
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127 | |
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128 | /// \brief Initializes node iterator to point to the node of a given index. |
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129 | NodeIt& nth(NodeIt &i, int n) const { |
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130 | if( DM::range_check && (n<0 || n>int(length())) ) |
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131 | fault("DirPath::nth: index out of range"); |
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132 | return i=NodeIt(*this, n); |
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133 | } |
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134 | |
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135 | /// \brief Initializes edge iterator to point to the edge of a given index. |
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136 | EdgeIt& nth(EdgeIt &i, int n) const { |
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137 | if( DM::range_check && (n<0 || n>=int(length())) ) |
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138 | fault("DirPath::nth: index out of range"); |
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139 | return i=EdgeIt(*this, n); |
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140 | } |
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141 | |
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142 | /// Checks validity of a node or edge iterator. |
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143 | template<typename It> |
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144 | static |
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145 | bool valid(const It &i) { return i.valid(); } |
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146 | |
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147 | /// Steps the given node or edge iterator. |
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148 | template<typename It> |
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149 | static |
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150 | It& next(It &e) { |
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151 | if( DM::range_check && !e.valid() ) |
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152 | fault("DirPath::next() on invalid iterator"); |
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153 | return ++e; |
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154 | } |
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155 | |
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156 | /// \brief Returns node iterator pointing to the head node of the |
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157 | /// given edge iterator. |
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158 | NodeIt head(const EdgeIt& e) const { |
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159 | if( DM::range_check && !e.valid() ) |
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160 | fault("DirPath::head() on invalid iterator"); |
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161 | return NodeIt(*this, e.idx+1); |
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162 | } |
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163 | |
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164 | /// \brief Returns node iterator pointing to the tail node of the |
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165 | /// given edge iterator. |
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166 | NodeIt tail(const EdgeIt& e) const { |
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167 | if( DM::range_check && !e.valid() ) |
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168 | fault("DirPath::tail() on invalid iterator"); |
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169 | return NodeIt(*this, e.idx); |
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170 | } |
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171 | |
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172 | |
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173 | /* Iterator classes */ |
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174 | |
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175 | /** |
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176 | * \brief Iterator class to iterate on the edges of the paths |
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177 | * |
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178 | * \ingroup paths |
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179 | * This class is used to iterate on the edges of the paths |
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180 | * |
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181 | * Of course it converts to Graph::Edge |
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182 | * |
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183 | * \todo Its interface differs from the standard edge iterator. |
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184 | * Yes, it shouldn't. |
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185 | */ |
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186 | class EdgeIt { |
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187 | friend class DirPath; |
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188 | |
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189 | int idx; |
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190 | const DirPath *p; |
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191 | public: |
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192 | /// Default constructor |
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193 | EdgeIt() {} |
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194 | /// Invalid constructor |
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195 | EdgeIt(Invalid) : idx(-1), p(0) {} |
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196 | /// Constructor with starting point |
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197 | EdgeIt(const DirPath &_p, int _idx = 0) : |
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198 | idx(_idx), p(&_p) { validate(); } |
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199 | |
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200 | ///Validity check |
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201 | bool valid() const { return idx!=-1; } |
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202 | |
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203 | ///Conversion to Graph::Edge |
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204 | operator GraphEdge () const { |
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205 | return valid() ? p->edges[idx] : INVALID; |
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206 | } |
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207 | |
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208 | /// Next edge |
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209 | EdgeIt& operator++() { ++idx; validate(); return *this; } |
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210 | |
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211 | /// Comparison operator |
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212 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
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213 | /// Comparison operator |
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214 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
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215 | /// Comparison operator |
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216 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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217 | |
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218 | private: |
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219 | // FIXME: comparison between signed and unsigned... |
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220 | // Jo ez igy? Vagy esetleg legyen a length() int? |
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221 | void validate() { if( size_t(idx) >= p->length() ) idx=-1; } |
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222 | }; |
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223 | |
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224 | /** |
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225 | * \brief Iterator class to iterate on the nodes of the paths |
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226 | * |
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227 | * \ingroup paths |
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228 | * This class is used to iterate on the nodes of the paths |
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229 | * |
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230 | * Of course it converts to Graph::Node |
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231 | * |
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232 | * \todo Its interface differs from the standard node iterator. |
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233 | * Yes, it shouldn't. |
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234 | */ |
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235 | class NodeIt { |
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236 | friend class DirPath; |
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237 | |
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238 | int idx; |
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239 | const DirPath *p; |
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240 | public: |
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241 | /// Default constructor |
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242 | NodeIt() {} |
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243 | /// Invalid constructor |
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244 | NodeIt(Invalid) : idx(-1), p(0) {} |
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245 | /// Constructor with starting point |
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246 | NodeIt(const DirPath &_p, int _idx = 0) : |
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247 | idx(_idx), p(&_p) { validate(); } |
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248 | |
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249 | ///Validity check |
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250 | bool valid() const { return idx!=-1; } |
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251 | |
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252 | ///Conversion to Graph::Node |
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253 | operator const GraphNode& () const { |
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254 | if(idx >= p->length()) |
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255 | return p->to(); |
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256 | else if(idx >= 0) |
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257 | return p->gr->tail(p->edges[idx]); |
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258 | else |
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259 | return INVALID; |
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260 | } |
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261 | /// Next node |
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262 | NodeIt& operator++() { ++idx; validate(); return *this; } |
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263 | |
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264 | /// Comparison operator |
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265 | bool operator==(const NodeIt& e) const { return idx==e.idx; } |
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266 | /// Comparison operator |
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267 | bool operator!=(const NodeIt& e) const { return idx!=e.idx; } |
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268 | /// Comparison operator |
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269 | bool operator<(const NodeIt& e) const { return idx<e.idx; } |
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270 | |
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271 | private: |
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272 | void validate() { if( size_t(idx) > p->length() ) idx=-1; } |
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273 | }; |
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274 | |
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275 | friend class Builder; |
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276 | |
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277 | /** |
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278 | * \brief Class to build paths |
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279 | * |
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280 | * \ingroup paths |
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281 | * This class is used to fill a path with edges. |
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282 | * |
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283 | * You can push new edges to the front and to the back of the path in |
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284 | * arbitrary order then you should commit these changes to the graph. |
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285 | * |
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286 | * Fundamentally, for most "Paths" (classes fulfilling the |
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287 | * PathConcept) while the builder is active (after the first modifying |
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288 | * operation and until the commit()) the original Path is in a |
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289 | * "transitional" state (operations on it have undefined result). But |
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290 | * in the case of DirPath the original path remains unchanged until the |
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291 | * commit. However we don't recomend that you use this feature. |
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292 | */ |
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293 | class Builder { |
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294 | DirPath &P; |
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295 | Container front, back; |
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296 | |
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297 | public: |
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298 | ///\param _P the path you want to fill in. |
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299 | /// |
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300 | Builder(DirPath &_P) : P(_P) {} |
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301 | |
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302 | /// Sets the starting node of the path. |
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303 | |
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304 | /// Sets the starting node of the path. Edge added to the path |
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305 | /// afterwards have to be incident to this node. |
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306 | /// It should be called iff the path is empty and before any call to |
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307 | /// \ref pushFront() or \ref pushBack() |
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308 | void setStartNode(const GraphNode &) {} |
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309 | |
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310 | ///Push a new edge to the front of the path |
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311 | |
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312 | ///Push a new edge to the front of the path. |
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313 | ///\sa setStartNode |
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314 | void pushFront(const GraphEdge& e) { |
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315 | if( DM::consistensy_check && !empty() && P.gr->head(e)!=from() ) { |
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316 | fault("DirPath::Builder::pushFront: nonincident edge"); |
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317 | } |
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318 | front.push_back(e); |
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319 | } |
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320 | |
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321 | ///Push a new edge to the back of the path |
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322 | |
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323 | ///Push a new edge to the back of the path. |
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324 | ///\sa setStartNode |
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325 | void pushBack(const GraphEdge& e) { |
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326 | if( DM::consistensy_check && !empty() && P.gr->tail(e)!=to() ) { |
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327 | fault("DirPath::Builder::pushBack: nonincident edge"); |
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328 | } |
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329 | back.push_back(e); |
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330 | } |
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331 | |
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332 | ///Commit the changes to the path. |
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333 | void commit() { |
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334 | if( !(front.empty() && back.empty()) ) { |
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335 | Container tmp; |
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336 | tmp.reserve(front.size()+back.size()+P.length()); |
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337 | tmp.insert(tmp.end(), front.rbegin(), front.rend()); |
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338 | tmp.insert(tmp.end(), P.edges.begin(), P.edges.end()); |
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339 | tmp.insert(tmp.end(), back.begin(), back.end()); |
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340 | P.edges.swap(tmp); |
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341 | front.clear(); |
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342 | back.clear(); |
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343 | } |
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344 | } |
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345 | |
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346 | // FIXME: Hmm, pontosan hogy is kene ezt csinalni? |
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347 | // Hogy kenyelmes egy ilyet hasznalni? |
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348 | |
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349 | ///Reserve storage for the builder in advance. |
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350 | |
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351 | ///If you know an reasonable upper bound of the number of the edges |
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352 | ///to add, using this function you can speed up the building. |
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353 | void reserve(size_t r) { |
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354 | front.reserve(r); |
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355 | back.reserve(r); |
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356 | } |
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357 | |
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358 | private: |
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359 | bool empty() { |
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360 | return front.empty() && back.empty() && P.empty(); |
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361 | } |
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362 | |
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363 | GraphNode from() const { |
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364 | if( ! front.empty() ) |
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365 | return P.gr->tail(front[front.size()-1]); |
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366 | else if( ! P.empty() ) |
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367 | return P.gr->tail(P.edges[0]); |
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368 | else if( ! back.empty() ) |
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369 | return P.gr->tail(back[0]); |
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370 | else |
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371 | return INVALID; |
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372 | } |
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373 | GraphNode to() const { |
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374 | if( ! back.empty() ) |
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375 | return P.gr->head(back[back.size()-1]); |
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376 | else if( ! P.empty() ) |
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377 | return P.gr->head(P.edges[P.length()-1]); |
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378 | else if( ! front.empty() ) |
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379 | return P.gr->head(front[0]); |
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380 | else |
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381 | return INVALID; |
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382 | } |
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383 | |
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384 | }; |
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385 | |
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386 | }; |
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387 | |
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388 | |
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389 | |
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390 | |
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391 | |
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392 | |
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393 | |
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394 | |
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395 | |
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396 | |
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397 | /**********************************************************************/ |
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398 | |
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399 | |
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400 | //! \brief A structure for representing undirected path in a graph. |
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401 | //! |
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402 | //! A structure for representing undirected path in a graph. Ie. this is |
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403 | //! a path in a \e directed graph but the edges should not be directed |
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404 | //! forward. |
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405 | //! |
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406 | //! \param Graph The graph type in which the path is. |
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407 | //! \param DM DebugMode, defaults to DefaultDebugMode. |
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408 | //! |
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409 | //! In a sense, the path can be treated as a graph, for is has \c NodeIt |
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410 | //! and \c EdgeIt with the same usage. These types converts to the \c Node |
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411 | //! and \c Edge of the original graph. |
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412 | //! |
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413 | //! \todo Thoroughfully check all the range and consistency tests. |
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414 | template<typename Graph, typename DM = DefaultDebugMode> |
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415 | class UndirPath { |
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416 | public: |
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417 | /// Edge type of the underlying graph. |
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418 | typedef typename Graph::Edge GraphEdge; |
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419 | /// Node type of the underlying graph. |
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420 | typedef typename Graph::Node GraphNode; |
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421 | class NodeIt; |
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422 | class EdgeIt; |
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423 | |
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424 | protected: |
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425 | const Graph *gr; |
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426 | typedef std::vector<GraphEdge> Container; |
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427 | Container edges; |
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428 | |
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429 | public: |
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430 | |
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431 | /// \param _G The graph in which the path is. |
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432 | /// |
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433 | UndirPath(const Graph &_G) : gr(&_G) {} |
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434 | |
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435 | /// \brief Subpath constructor. |
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436 | /// |
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437 | /// Subpath defined by two nodes. |
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438 | /// \warning It is an error if the two edges are not in order! |
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439 | UndirPath(const UndirPath &P, const NodeIt &a, const NodeIt &b) { |
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440 | if( DM::range_check && (!a.valid() || !b.valid) ) { |
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441 | // FIXME: this check should be more elaborate... |
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442 | fault("UndirPath, subpath ctor: invalid bounding nodes"); |
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443 | } |
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444 | gr = P.gr; |
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445 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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446 | } |
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447 | |
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448 | /// \brief Subpath constructor. |
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449 | /// |
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450 | /// Subpath defined by two edges. Contains edges in [a,b) |
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451 | /// \warning It is an error if the two edges are not in order! |
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452 | UndirPath(const UndirPath &P, const EdgeIt &a, const EdgeIt &b) { |
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453 | if( DM::range_check && (!a.valid() || !b.valid) ) { |
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454 | // FIXME: this check should be more elaborate... |
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455 | fault("UndirPath, subpath ctor: invalid bounding nodes"); |
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456 | } |
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457 | gr = P.gr; |
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458 | edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); |
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459 | } |
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460 | |
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461 | /// Length of the path. |
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462 | size_t length() const { return edges.size(); } |
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463 | /// Returns whether the path is empty. |
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464 | bool empty() const { return edges.empty(); } |
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465 | |
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466 | /// Resets the path to an empty path. |
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467 | void clear() { edges.clear(); } |
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468 | |
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469 | /// \brief Starting point of the path. |
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470 | /// |
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471 | /// Starting point of the path. |
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472 | /// Returns INVALID if the path is empty. |
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473 | GraphNode from() const { |
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474 | return empty() ? INVALID : gr->tail(edges[0]); |
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475 | } |
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476 | /// \brief End point of the path. |
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477 | /// |
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478 | /// End point of the path. |
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479 | /// Returns INVALID if the path is empty. |
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480 | GraphNode to() const { |
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481 | return empty() ? INVALID : gr->head(edges[length()-1]); |
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482 | } |
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483 | |
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484 | /// \brief Initializes node or edge iterator to point to the first |
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485 | /// node or edge. |
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486 | /// |
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487 | /// \sa nth |
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488 | template<typename It> |
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489 | It& first(It &i) const { return i=It(*this); } |
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490 | |
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491 | /// \brief Initializes node iterator to point to the node of a given index. |
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492 | NodeIt& nth(NodeIt &i, int n) const { |
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493 | if( DM::range_check && (n<0 || n>int(length())) ) |
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494 | fault("UndirPath::nth: index out of range"); |
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495 | return i=NodeIt(*this, n); |
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496 | } |
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497 | |
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498 | /// \brief Initializes edge iterator to point to the edge of a given index. |
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499 | EdgeIt& nth(EdgeIt &i, int n) const { |
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500 | if( DM::range_check && (n<0 || n>=int(length())) ) |
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501 | fault("UndirPath::nth: index out of range"); |
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502 | return i=EdgeIt(*this, n); |
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503 | } |
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504 | |
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505 | /// Checks validity of a node or edge iterator. |
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506 | template<typename It> |
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507 | static |
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508 | bool valid(const It &i) { return i.valid(); } |
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509 | |
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510 | /// Steps the given node or edge iterator. |
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511 | template<typename It> |
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512 | static |
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513 | It& next(It &e) { |
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514 | if( DM::range_check && !e.valid() ) |
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515 | fault("UndirPath::next() on invalid iterator"); |
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516 | return ++e; |
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517 | } |
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518 | |
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519 | /// \brief Returns node iterator pointing to the head node of the |
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520 | /// given edge iterator. |
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521 | NodeIt head(const EdgeIt& e) const { |
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522 | if( DM::range_check && !e.valid() ) |
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523 | fault("UndirPath::head() on invalid iterator"); |
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524 | return NodeIt(*this, e.idx+1); |
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525 | } |
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526 | |
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527 | /// \brief Returns node iterator pointing to the tail node of the |
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528 | /// given edge iterator. |
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529 | NodeIt tail(const EdgeIt& e) const { |
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530 | if( DM::range_check && !e.valid() ) |
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531 | fault("UndirPath::tail() on invalid iterator"); |
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532 | return NodeIt(*this, e.idx); |
---|
533 | } |
---|
534 | |
---|
535 | |
---|
536 | |
---|
537 | /** |
---|
538 | * \brief Iterator class to iterate on the edges of the paths |
---|
539 | * |
---|
540 | * \ingroup paths |
---|
541 | * This class is used to iterate on the edges of the paths |
---|
542 | * |
---|
543 | * Of course it converts to Graph::Edge |
---|
544 | * |
---|
545 | * \todo Its interface differs from the standard edge iterator. |
---|
546 | * Yes, it shouldn't. |
---|
547 | */ |
---|
548 | class EdgeIt { |
---|
549 | friend class UndirPath; |
---|
550 | |
---|
551 | int idx; |
---|
552 | const UndirPath *p; |
---|
553 | public: |
---|
554 | /// Default constructor |
---|
555 | EdgeIt() {} |
---|
556 | /// Invalid constructor |
---|
557 | EdgeIt(Invalid) : idx(-1), p(0) {} |
---|
558 | /// Constructor with starting point |
---|
559 | EdgeIt(const UndirPath &_p, int _idx = 0) : |
---|
560 | idx(_idx), p(&_p) { validate(); } |
---|
561 | |
---|
562 | ///Validity check |
---|
563 | bool valid() const { return idx!=-1; } |
---|
564 | |
---|
565 | ///Conversion to Graph::Edge |
---|
566 | operator GraphEdge () const { |
---|
567 | return valid() ? p->edges[idx] : INVALID; |
---|
568 | } |
---|
569 | /// Next edge |
---|
570 | EdgeIt& operator++() { ++idx; validate(); return *this; } |
---|
571 | |
---|
572 | /// Comparison operator |
---|
573 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
---|
574 | /// Comparison operator |
---|
575 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
---|
576 | /// Comparison operator |
---|
577 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
---|
578 | |
---|
579 | private: |
---|
580 | // FIXME: comparison between signed and unsigned... |
---|
581 | // Jo ez igy? Vagy esetleg legyen a length() int? |
---|
582 | void validate() { if( size_t(idx) >= p->length() ) idx=-1; } |
---|
583 | }; |
---|
584 | |
---|
585 | /** |
---|
586 | * \brief Iterator class to iterate on the nodes of the paths |
---|
587 | * |
---|
588 | * \ingroup paths |
---|
589 | * This class is used to iterate on the nodes of the paths |
---|
590 | * |
---|
591 | * Of course it converts to Graph::Node |
---|
592 | * |
---|
593 | * \todo Its interface differs from the standard node iterator. |
---|
594 | * Yes, it shouldn't. |
---|
595 | */ |
---|
596 | class NodeIt { |
---|
597 | friend class UndirPath; |
---|
598 | |
---|
599 | int idx; |
---|
600 | const UndirPath *p; |
---|
601 | public: |
---|
602 | /// Default constructor |
---|
603 | NodeIt() {} |
---|
604 | /// Invalid constructor |
---|
605 | NodeIt(Invalid) : idx(-1), p(0) {} |
---|
606 | /// Constructor with starting point |
---|
607 | NodeIt(const UndirPath &_p, int _idx = 0) : |
---|
608 | idx(_idx), p(&_p) { validate(); } |
---|
609 | |
---|
610 | ///Validity check |
---|
611 | bool valid() const { return idx!=-1; } |
---|
612 | |
---|
613 | ///Conversion to Graph::Node |
---|
614 | operator const GraphNode& () const { |
---|
615 | if(idx >= p->length()) |
---|
616 | return p->to(); |
---|
617 | else if(idx >= 0) |
---|
618 | return p->gr->tail(p->edges[idx]); |
---|
619 | else |
---|
620 | return INVALID; |
---|
621 | } |
---|
622 | /// Next node |
---|
623 | NodeIt& operator++() { ++idx; validate(); return *this; } |
---|
624 | |
---|
625 | /// Comparison operator |
---|
626 | bool operator==(const NodeIt& e) const { return idx==e.idx; } |
---|
627 | /// Comparison operator |
---|
628 | bool operator!=(const NodeIt& e) const { return idx!=e.idx; } |
---|
629 | /// Comparison operator |
---|
630 | bool operator<(const NodeIt& e) const { return idx<e.idx; } |
---|
631 | |
---|
632 | private: |
---|
633 | void validate() { if( size_t(idx) > p->length() ) idx=-1; } |
---|
634 | }; |
---|
635 | |
---|
636 | friend class Builder; |
---|
637 | |
---|
638 | /** |
---|
639 | * \brief Class to build paths |
---|
640 | * |
---|
641 | * \ingroup paths |
---|
642 | * This class is used to fill a path with edges. |
---|
643 | * |
---|
644 | * You can push new edges to the front and to the back of the path in |
---|
645 | * arbitrary order then you should commit these changes to the graph. |
---|
646 | * |
---|
647 | * Fundamentally, for most "Paths" (classes fulfilling the |
---|
648 | * PathConcept) while the builder is active (after the first modifying |
---|
649 | * operation and until the commit()) the original Path is in a |
---|
650 | * "transitional" state (operations ot it have undefined result). But |
---|
651 | * in the case of UndirPath the original path is unchanged until the |
---|
652 | * commit. However we don't recomend that you use this feature. |
---|
653 | */ |
---|
654 | class Builder { |
---|
655 | UndirPath &P; |
---|
656 | Container front, back; |
---|
657 | |
---|
658 | public: |
---|
659 | ///\param _P the path you want to fill in. |
---|
660 | /// |
---|
661 | Builder(UndirPath &_P) : P(_P) {} |
---|
662 | |
---|
663 | /// Sets the starting node of the path. |
---|
664 | |
---|
665 | /// Sets the starting node of the path. Edge added to the path |
---|
666 | /// afterwards have to be incident to this node. |
---|
667 | /// It should be called iff the path is empty and before any call to |
---|
668 | /// \ref pushFront() or \ref pushBack() |
---|
669 | void setStartNode(const GraphNode &) {} |
---|
670 | |
---|
671 | ///Push a new edge to the front of the path |
---|
672 | |
---|
673 | ///Push a new edge to the front of the path. |
---|
674 | ///\sa setStartNode |
---|
675 | void pushFront(const GraphEdge& e) { |
---|
676 | if( DM::consistensy_check && !empty() && P.gr->head(e)!=from() ) { |
---|
677 | fault("UndirPath::Builder::pushFront: nonincident edge"); |
---|
678 | } |
---|
679 | front.push_back(e); |
---|
680 | } |
---|
681 | |
---|
682 | ///Push a new edge to the back of the path |
---|
683 | |
---|
684 | ///Push a new edge to the back of the path. |
---|
685 | ///\sa setStartNode |
---|
686 | void pushBack(const GraphEdge& e) { |
---|
687 | if( DM::consistensy_check && !empty() && P.gr->tail(e)!=to() ) { |
---|
688 | fault("UndirPath::Builder::pushBack: nonincident edge"); |
---|
689 | } |
---|
690 | back.push_back(e); |
---|
691 | } |
---|
692 | |
---|
693 | ///Commit the changes to the path. |
---|
694 | void commit() { |
---|
695 | if( !(front.empty() && back.empty()) ) { |
---|
696 | Container tmp; |
---|
697 | tmp.reserve(front.size()+back.size()+P.length()); |
---|
698 | tmp.insert(tmp.end(), front.rbegin(), front.rend()); |
---|
699 | tmp.insert(tmp.end(), P.edges.begin(), P.edges.end()); |
---|
700 | tmp.insert(tmp.end(), back.begin(), back.end()); |
---|
701 | P.edges.swap(tmp); |
---|
702 | front.clear(); |
---|
703 | back.clear(); |
---|
704 | } |
---|
705 | } |
---|
706 | |
---|
707 | // FIXME: Hmm, pontosan hogy is kene ezt csinalni? |
---|
708 | // Hogy kenyelmes egy ilyet hasznalni? |
---|
709 | |
---|
710 | ///Reserve storage for the builder in advance. |
---|
711 | |
---|
712 | ///If you know an reasonable upper bound of the number of the edges |
---|
713 | ///to add, using this function you can speed up the building. |
---|
714 | void reserve(size_t r) { |
---|
715 | front.reserve(r); |
---|
716 | back.reserve(r); |
---|
717 | } |
---|
718 | |
---|
719 | private: |
---|
720 | bool empty() { |
---|
721 | return front.empty() && back.empty() && P.empty(); |
---|
722 | } |
---|
723 | |
---|
724 | GraphNode from() const { |
---|
725 | if( ! front.empty() ) |
---|
726 | return P.gr->tail(front[front.size()-1]); |
---|
727 | else if( ! P.empty() ) |
---|
728 | return P.gr->tail(P.edges[0]); |
---|
729 | else if( ! back.empty() ) |
---|
730 | return P.gr->tail(back[0]); |
---|
731 | else |
---|
732 | return INVALID; |
---|
733 | } |
---|
734 | GraphNode to() const { |
---|
735 | if( ! back.empty() ) |
---|
736 | return P.gr->head(back[back.size()-1]); |
---|
737 | else if( ! P.empty() ) |
---|
738 | return P.gr->head(P.edges[P.length()-1]); |
---|
739 | else if( ! front.empty() ) |
---|
740 | return P.gr->head(front[0]); |
---|
741 | else |
---|
742 | return INVALID; |
---|
743 | } |
---|
744 | |
---|
745 | }; |
---|
746 | |
---|
747 | }; |
---|
748 | |
---|
749 | |
---|
750 | |
---|
751 | |
---|
752 | |
---|
753 | |
---|
754 | |
---|
755 | |
---|
756 | |
---|
757 | |
---|
758 | /**********************************************************************/ |
---|
759 | |
---|
760 | |
---|
761 | /* Ennek az allocatorosdinak sokkal jobban utana kene nezni a hasznalata |
---|
762 | elott. Eleg bonyinak nez ki, ahogyan azokat az STL-ben hasznaljak. */ |
---|
763 | |
---|
764 | template<typename Graph> |
---|
765 | class DynamicPath { |
---|
766 | |
---|
767 | public: |
---|
768 | typedef typename Graph::Edge GraphEdge; |
---|
769 | typedef typename Graph::Node GraphNode; |
---|
770 | class NodeIt; |
---|
771 | class EdgeIt; |
---|
772 | |
---|
773 | protected: |
---|
774 | Graph& G; |
---|
775 | // FIXME: ehelyett eleg lenne tarolni ket boolt: a ket szelso el |
---|
776 | // iranyitasat: |
---|
777 | GraphNode _first, _last; |
---|
778 | typedef std::deque<GraphEdge> Container; |
---|
779 | Container edges; |
---|
780 | |
---|
781 | public: |
---|
782 | |
---|
783 | DynamicPath(Graph &_G) : G(_G), _first(INVALID), _last(INVALID) {} |
---|
784 | |
---|
785 | /// Subpath defined by two nodes. |
---|
786 | /// Nodes may be in reversed order, then |
---|
787 | /// we contstruct the reversed path. |
---|
788 | DynamicPath(const DynamicPath &P, const NodeIt &a, const NodeIt &b); |
---|
789 | /// Subpath defined by two edges. Contains edges in [a,b) |
---|
790 | /// It is an error if the two edges are not in order! |
---|
791 | DynamicPath(const DynamicPath &P, const EdgeIt &a, const EdgeIt &b); |
---|
792 | |
---|
793 | size_t length() const { return edges.size(); } |
---|
794 | GraphNode from() const { return _first; } |
---|
795 | GraphNode to() const { return _last; } |
---|
796 | |
---|
797 | NodeIt& first(NodeIt &n) const { return nth(n, 0); } |
---|
798 | EdgeIt& first(EdgeIt &e) const { return nth(e, 0); } |
---|
799 | template<typename It> |
---|
800 | It first() const { |
---|
801 | It e; |
---|
802 | first(e); |
---|
803 | return e; |
---|
804 | } |
---|
805 | |
---|
806 | NodeIt& nth(NodeIt &, size_t) const; |
---|
807 | EdgeIt& nth(EdgeIt &, size_t) const; |
---|
808 | template<typename It> |
---|
809 | It nth(size_t n) const { |
---|
810 | It e; |
---|
811 | nth(e, n); |
---|
812 | return e; |
---|
813 | } |
---|
814 | |
---|
815 | bool valid(const NodeIt &n) const { return n.idx <= length(); } |
---|
816 | bool valid(const EdgeIt &e) const { return e.it < edges.end(); } |
---|
817 | |
---|
818 | bool isForward(const EdgeIt &e) const { return e.forw; } |
---|
819 | |
---|
820 | /// index of a node on the path. Returns length+2 for the invalid NodeIt |
---|
821 | int index(const NodeIt &n) const { return n.idx; } |
---|
822 | /// index of an edge on the path. Returns length+1 for the invalid EdgeIt |
---|
823 | int index(const EdgeIt &e) const { return e.it - edges.begin(); } |
---|
824 | |
---|
825 | EdgeIt& next(EdgeIt &e) const; |
---|
826 | NodeIt& next(NodeIt &n) const; |
---|
827 | template <typename It> |
---|
828 | It getNext(It it) const { |
---|
829 | It tmp(it); return next(tmp); |
---|
830 | } |
---|
831 | |
---|
832 | // A path is constructed using the following four functions. |
---|
833 | // They return false if the requested operation is inconsistent |
---|
834 | // with the path constructed so far. |
---|
835 | // If your path has only one edge you MUST set either "from" or "to"! |
---|
836 | // So you probably SHOULD call it in any case to be safe (and check the |
---|
837 | // returned value to check if your path is consistent with your idea). |
---|
838 | bool pushFront(const GraphEdge &e); |
---|
839 | bool pushBack(const GraphEdge &e); |
---|
840 | bool setFrom(const GraphNode &n); |
---|
841 | bool setTo(const GraphNode &n); |
---|
842 | |
---|
843 | // WARNING: these two functions return the head/tail of an edge with |
---|
844 | // respect to the direction of the path! |
---|
845 | // So G.head(P.graphEdge(e)) == P.graphNode(P.head(e)) holds only if |
---|
846 | // P.forward(e) is true (or the edge is a loop)! |
---|
847 | NodeIt head(const EdgeIt& e) const; |
---|
848 | NodeIt tail(const EdgeIt& e) const; |
---|
849 | |
---|
850 | // FIXME: ezeknek valami jobb nev kellene!!! |
---|
851 | GraphEdge graphEdge(const EdgeIt& e) const; |
---|
852 | GraphNode graphNode(const NodeIt& n) const; |
---|
853 | |
---|
854 | |
---|
855 | /*** Iterator classes ***/ |
---|
856 | class EdgeIt { |
---|
857 | friend class DynamicPath; |
---|
858 | |
---|
859 | typename Container::const_iterator it; |
---|
860 | bool forw; |
---|
861 | public: |
---|
862 | // FIXME: jarna neki ilyen is... |
---|
863 | // EdgeIt(Invalid); |
---|
864 | |
---|
865 | bool forward() const { return forw; } |
---|
866 | |
---|
867 | bool operator==(const EdgeIt& e) const { return it==e.it; } |
---|
868 | bool operator!=(const EdgeIt& e) const { return it!=e.it; } |
---|
869 | bool operator<(const EdgeIt& e) const { return it<e.it; } |
---|
870 | }; |
---|
871 | |
---|
872 | class NodeIt { |
---|
873 | friend class DynamicPath; |
---|
874 | |
---|
875 | size_t idx; |
---|
876 | bool tail; // Is this node the tail of the edge with same idx? |
---|
877 | |
---|
878 | public: |
---|
879 | // FIXME: jarna neki ilyen is... |
---|
880 | // NodeIt(Invalid); |
---|
881 | |
---|
882 | bool operator==(const NodeIt& n) const { return idx==n.idx; } |
---|
883 | bool operator!=(const NodeIt& n) const { return idx!=n.idx; } |
---|
884 | bool operator<(const NodeIt& n) const { return idx<n.idx; } |
---|
885 | }; |
---|
886 | |
---|
887 | private: |
---|
888 | bool edgeIncident(const GraphEdge &e, const GraphNode &a, |
---|
889 | GraphNode &b); |
---|
890 | bool connectTwoEdges(const GraphEdge &e, const GraphEdge &f); |
---|
891 | }; |
---|
892 | |
---|
893 | template<typename Gr> |
---|
894 | typename DynamicPath<Gr>::EdgeIt& |
---|
895 | DynamicPath<Gr>::next(DynamicPath::EdgeIt &e) const { |
---|
896 | if( e.it == edges.end() ) |
---|
897 | return e; |
---|
898 | |
---|
899 | GraphNode common_node = ( e.forw ? G.head(*e.it) : G.tail(*e.it) ); |
---|
900 | ++e.it; |
---|
901 | |
---|
902 | // Invalid edgeit is always forward :) |
---|
903 | if( e.it == edges.end() ) { |
---|
904 | e.forw = true; |
---|
905 | return e; |
---|
906 | } |
---|
907 | |
---|
908 | e.forw = ( G.tail(*e.it) == common_node ); |
---|
909 | return e; |
---|
910 | } |
---|
911 | |
---|
912 | template<typename Gr> |
---|
913 | typename DynamicPath<Gr>::NodeIt& DynamicPath<Gr>::next(NodeIt &n) const { |
---|
914 | if( n.idx >= length() ) { |
---|
915 | // FIXME: invalid |
---|
916 | n.idx = length()+1; |
---|
917 | return n; |
---|
918 | } |
---|
919 | |
---|
920 | |
---|
921 | GraphNode next_node = ( n.tail ? G.head(edges[n.idx]) : |
---|
922 | G.tail(edges[n.idx]) ); |
---|
923 | ++n.idx; |
---|
924 | if( n.idx < length() ) { |
---|
925 | n.tail = ( next_node == G.tail(edges[n.idx]) ); |
---|
926 | } |
---|
927 | else { |
---|
928 | n.tail = true; |
---|
929 | } |
---|
930 | |
---|
931 | return n; |
---|
932 | } |
---|
933 | |
---|
934 | template<typename Gr> |
---|
935 | bool DynamicPath<Gr>::edgeIncident(const GraphEdge &e, const GraphNode &a, |
---|
936 | GraphNode &b) { |
---|
937 | if( G.tail(e) == a ) { |
---|
938 | b=G.head(e); |
---|
939 | return true; |
---|
940 | } |
---|
941 | if( G.head(e) == a ) { |
---|
942 | b=G.tail(e); |
---|
943 | return true; |
---|
944 | } |
---|
945 | return false; |
---|
946 | } |
---|
947 | |
---|
948 | template<typename Gr> |
---|
949 | bool DynamicPath<Gr>::connectTwoEdges(const GraphEdge &e, |
---|
950 | const GraphEdge &f) { |
---|
951 | if( edgeIncident(f, G.tail(e), _last) ) { |
---|
952 | _first = G.head(e); |
---|
953 | return true; |
---|
954 | } |
---|
955 | if( edgeIncident(f, G.head(e), _last) ) { |
---|
956 | _first = G.tail(e); |
---|
957 | return true; |
---|
958 | } |
---|
959 | return false; |
---|
960 | } |
---|
961 | |
---|
962 | template<typename Gr> |
---|
963 | bool DynamicPath<Gr>::pushFront(const GraphEdge &e) { |
---|
964 | if( G.valid(_first) ) { |
---|
965 | if( edgeIncident(e, _first, _first) ) { |
---|
966 | edges.push_front(e); |
---|
967 | return true; |
---|
968 | } |
---|
969 | else |
---|
970 | return false; |
---|
971 | } |
---|
972 | else if( length() < 1 || connectTwoEdges(e, edges[0]) ) { |
---|
973 | edges.push_front(e); |
---|
974 | return true; |
---|
975 | } |
---|
976 | else |
---|
977 | return false; |
---|
978 | } |
---|
979 | |
---|
980 | template<typename Gr> |
---|
981 | bool DynamicPath<Gr>::pushBack(const GraphEdge &e) { |
---|
982 | if( G.valid(_last) ) { |
---|
983 | if( edgeIncident(e, _last, _last) ) { |
---|
984 | edges.push_back(e); |
---|
985 | return true; |
---|
986 | } |
---|
987 | else |
---|
988 | return false; |
---|
989 | } |
---|
990 | else if( length() < 1 || connectTwoEdges(edges[0], e) ) { |
---|
991 | edges.push_back(e); |
---|
992 | return true; |
---|
993 | } |
---|
994 | else |
---|
995 | return false; |
---|
996 | } |
---|
997 | |
---|
998 | |
---|
999 | template<typename Gr> |
---|
1000 | bool DynamicPath<Gr>::setFrom(const GraphNode &n) { |
---|
1001 | if( G.valid(_first) ) { |
---|
1002 | return _first == n; |
---|
1003 | } |
---|
1004 | else { |
---|
1005 | if( length() > 0) { |
---|
1006 | if( edgeIncident(edges[0], n, _last) ) { |
---|
1007 | _first = n; |
---|
1008 | return true; |
---|
1009 | } |
---|
1010 | else return false; |
---|
1011 | } |
---|
1012 | else { |
---|
1013 | _first = _last = n; |
---|
1014 | return true; |
---|
1015 | } |
---|
1016 | } |
---|
1017 | } |
---|
1018 | |
---|
1019 | template<typename Gr> |
---|
1020 | bool DynamicPath<Gr>::setTo(const GraphNode &n) { |
---|
1021 | if( G.valid(_last) ) { |
---|
1022 | return _last == n; |
---|
1023 | } |
---|
1024 | else { |
---|
1025 | if( length() > 0) { |
---|
1026 | if( edgeIncident(edges[0], n, _first) ) { |
---|
1027 | _last = n; |
---|
1028 | return true; |
---|
1029 | } |
---|
1030 | else return false; |
---|
1031 | } |
---|
1032 | else { |
---|
1033 | _first = _last = n; |
---|
1034 | return true; |
---|
1035 | } |
---|
1036 | } |
---|
1037 | } |
---|
1038 | |
---|
1039 | |
---|
1040 | template<typename Gr> |
---|
1041 | typename DynamicPath<Gr>::NodeIt |
---|
1042 | DynamicPath<Gr>::tail(const EdgeIt& e) const { |
---|
1043 | NodeIt n; |
---|
1044 | |
---|
1045 | if( e.it == edges.end() ) { |
---|
1046 | // FIXME: invalid-> invalid |
---|
1047 | n.idx = length() + 1; |
---|
1048 | n.tail = true; |
---|
1049 | return n; |
---|
1050 | } |
---|
1051 | |
---|
1052 | n.idx = e.it-edges.begin(); |
---|
1053 | n.tail = e.forw; |
---|
1054 | return n; |
---|
1055 | } |
---|
1056 | |
---|
1057 | template<typename Gr> |
---|
1058 | typename DynamicPath<Gr>::NodeIt |
---|
1059 | DynamicPath<Gr>::head(const EdgeIt& e) const { |
---|
1060 | if( e.it == edges.end()-1 ) { |
---|
1061 | return _last; |
---|
1062 | } |
---|
1063 | |
---|
1064 | EdgeIt next_edge = e; |
---|
1065 | next(next_edge); |
---|
1066 | return tail(next_edge); |
---|
1067 | } |
---|
1068 | |
---|
1069 | template<typename Gr> |
---|
1070 | typename DynamicPath<Gr>::GraphEdge |
---|
1071 | DynamicPath<Gr>::graphEdge(const EdgeIt& e) const { |
---|
1072 | if( e.it != edges.end() ) { |
---|
1073 | return *e.it; |
---|
1074 | } |
---|
1075 | else { |
---|
1076 | return INVALID; |
---|
1077 | } |
---|
1078 | } |
---|
1079 | |
---|
1080 | template<typename Gr> |
---|
1081 | typename DynamicPath<Gr>::GraphNode |
---|
1082 | DynamicPath<Gr>::graphNode(const NodeIt& n) const { |
---|
1083 | if( n.idx < length() ) { |
---|
1084 | return n.tail ? G.tail(edges[n.idx]) : G.head(edges[n.idx]); |
---|
1085 | } |
---|
1086 | else if( n.idx == length() ) { |
---|
1087 | return _last; |
---|
1088 | } |
---|
1089 | else { |
---|
1090 | return INVALID; |
---|
1091 | } |
---|
1092 | } |
---|
1093 | |
---|
1094 | template<typename Gr> |
---|
1095 | typename DynamicPath<Gr>::EdgeIt& |
---|
1096 | DynamicPath<Gr>::nth(EdgeIt &e, size_t k) const { |
---|
1097 | if( k>=length() ) { |
---|
1098 | // FIXME: invalid EdgeIt |
---|
1099 | e.it = edges.end(); |
---|
1100 | e.forw = true; |
---|
1101 | return e; |
---|
1102 | } |
---|
1103 | |
---|
1104 | e.it = edges.begin()+k; |
---|
1105 | if(k==0) { |
---|
1106 | e.forw = ( G.tail(*e.it) == _first ); |
---|
1107 | } |
---|
1108 | else { |
---|
1109 | e.forw = ( G.tail(*e.it) == G.tail(edges[k-1]) || |
---|
1110 | G.tail(*e.it) == G.head(edges[k-1]) ); |
---|
1111 | } |
---|
1112 | return e; |
---|
1113 | } |
---|
1114 | |
---|
1115 | template<typename Gr> |
---|
1116 | typename DynamicPath<Gr>::NodeIt& |
---|
1117 | DynamicPath<Gr>::nth(NodeIt &n, size_t k) const { |
---|
1118 | if( k>length() ) { |
---|
1119 | // FIXME: invalid NodeIt |
---|
1120 | n.idx = length()+1; |
---|
1121 | n.tail = true; |
---|
1122 | return n; |
---|
1123 | } |
---|
1124 | if( k==length() ) { |
---|
1125 | n.idx = length(); |
---|
1126 | n.tail = true; |
---|
1127 | return n; |
---|
1128 | } |
---|
1129 | n = tail(nth<EdgeIt>(k)); |
---|
1130 | return n; |
---|
1131 | } |
---|
1132 | |
---|
1133 | // Reszut konstruktorok: |
---|
1134 | |
---|
1135 | |
---|
1136 | template<typename Gr> |
---|
1137 | DynamicPath<Gr>::DynamicPath(const DynamicPath &P, const EdgeIt &a, |
---|
1138 | const EdgeIt &b) : |
---|
1139 | G(P.G), edges(a.it, b.it) // WARNING: if b.it < a.it this will blow up! |
---|
1140 | { |
---|
1141 | if( G.valid(P._first) && a.it < P.edges.end() ) { |
---|
1142 | _first = ( a.forw ? G.tail(*a.it) : G.head(*a.it) ); |
---|
1143 | if( b.it < P.edges.end() ) { |
---|
1144 | _last = ( b.forw ? G.tail(*b.it) : G.head(*b.it) ); |
---|
1145 | } |
---|
1146 | else { |
---|
1147 | _last = P._last; |
---|
1148 | } |
---|
1149 | } |
---|
1150 | } |
---|
1151 | |
---|
1152 | template<typename Gr> |
---|
1153 | DynamicPath<Gr>::DynamicPath(const DynamicPath &P, const NodeIt &a, |
---|
1154 | const NodeIt &b) : G(P.G) |
---|
1155 | { |
---|
1156 | if( !P.valid(a) || !P.valid(b) ) |
---|
1157 | return; |
---|
1158 | |
---|
1159 | int ai = a.idx, bi = b.idx; |
---|
1160 | if( bi<ai ) |
---|
1161 | std::swap(ai,bi); |
---|
1162 | |
---|
1163 | edges.resize(bi-ai); |
---|
1164 | copy(P.edges.begin()+ai, P.edges.begin()+bi, edges.begin()); |
---|
1165 | |
---|
1166 | _first = P.graphNode(a); |
---|
1167 | _last = P.graphNode(b); |
---|
1168 | } |
---|
1169 | |
---|
1170 | ///@} |
---|
1171 | |
---|
1172 | } // namespace lemon |
---|
1173 | |
---|
1174 | #endif // LEMON_PATH_H |
---|