[602] | 1 | // -*- c++ -*- |
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| 2 | #ifndef HUGO_BFS_DFS_H |
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| 3 | #define HUGO_BFS_DFS_H |
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| 4 | |
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[615] | 5 | /// \ingroup galgs |
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| 6 | /// \file |
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| 7 | /// \brief Bfs and dfs iterators. |
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[604] | 8 | /// |
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[615] | 9 | /// This file contains bfs and dfs iterator classes. |
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[604] | 10 | /// |
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[615] | 11 | // /// \author Marton Makai |
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[604] | 12 | |
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[602] | 13 | #include <queue> |
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| 14 | #include <stack> |
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| 15 | #include <utility> |
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| 16 | |
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| 17 | #include <hugo/invalid.h> |
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| 18 | |
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| 19 | namespace hugo { |
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| 20 | |
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| 21 | /// Bfs searches for the nodes wich are not marked in |
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| 22 | /// \c reached_map |
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[650] | 23 | /// Reached have to be a read-write bool node-map. |
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[615] | 24 | /// \ingroup galgs |
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[602] | 25 | template <typename Graph, /*typename OutEdgeIt,*/ |
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| 26 | typename ReachedMap/*=typename Graph::NodeMap<bool>*/ > |
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| 27 | class BfsIterator { |
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| 28 | protected: |
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| 29 | typedef typename Graph::Node Node; |
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| 30 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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| 31 | const Graph* graph; |
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| 32 | std::queue<Node> bfs_queue; |
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| 33 | ReachedMap& reached; |
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| 34 | bool b_node_newly_reached; |
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| 35 | OutEdgeIt actual_edge; |
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| 36 | bool own_reached_map; |
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| 37 | public: |
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| 38 | /// In that constructor \c _reached have to be a reference |
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[650] | 39 | /// for a bool bode-map. The algorithm will search for the |
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| 40 | /// initially \c false nodes |
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| 41 | /// in a bfs order. |
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[602] | 42 | BfsIterator(const Graph& _graph, ReachedMap& _reached) : |
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| 43 | graph(&_graph), reached(_reached), |
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| 44 | own_reached_map(false) { } |
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| 45 | /// The same as above, but the map storing the reached nodes |
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| 46 | /// is constructed dynamically to everywhere false. |
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[650] | 47 | /// \deprecated |
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[602] | 48 | BfsIterator(const Graph& _graph) : |
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| 49 | graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), |
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| 50 | own_reached_map(true) { } |
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[604] | 51 | /// The map storing the reached nodes have to be destroyed if |
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[602] | 52 | /// it was constructed dynamically |
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| 53 | ~BfsIterator() { if (own_reached_map) delete &reached; } |
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| 54 | /// This method markes \c s reached. |
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| 55 | /// If the queue is empty, then \c s is pushed in the bfs queue |
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| 56 | /// and the first out-edge is processed. |
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| 57 | /// If the queue is not empty, then \c s is simply pushed. |
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| 58 | void pushAndSetReached(Node s) { |
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| 59 | reached.set(s, true); |
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| 60 | if (bfs_queue.empty()) { |
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| 61 | bfs_queue.push(s); |
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| 62 | graph->first(actual_edge, s); |
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| 63 | if (graph->valid(actual_edge)) { |
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| 64 | Node w=graph->bNode(actual_edge); |
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| 65 | if (!reached[w]) { |
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| 66 | bfs_queue.push(w); |
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| 67 | reached.set(w, true); |
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| 68 | b_node_newly_reached=true; |
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| 69 | } else { |
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| 70 | b_node_newly_reached=false; |
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| 71 | } |
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| 72 | } |
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| 73 | } else { |
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| 74 | bfs_queue.push(s); |
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| 75 | } |
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| 76 | } |
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| 77 | /// As \c BfsIterator<Graph, ReachedMap> works as an edge-iterator, |
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| 78 | /// its \c operator++() iterates on the edges in a bfs order. |
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| 79 | BfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& |
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| 80 | operator++() { |
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| 81 | if (graph->valid(actual_edge)) { |
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| 82 | graph->next(actual_edge); |
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| 83 | if (graph->valid(actual_edge)) { |
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| 84 | Node w=graph->bNode(actual_edge); |
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| 85 | if (!reached[w]) { |
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| 86 | bfs_queue.push(w); |
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| 87 | reached.set(w, true); |
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| 88 | b_node_newly_reached=true; |
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| 89 | } else { |
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| 90 | b_node_newly_reached=false; |
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| 91 | } |
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| 92 | } |
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| 93 | } else { |
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| 94 | bfs_queue.pop(); |
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| 95 | if (!bfs_queue.empty()) { |
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| 96 | graph->first(actual_edge, bfs_queue.front()); |
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| 97 | if (graph->valid(actual_edge)) { |
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| 98 | Node w=graph->bNode(actual_edge); |
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| 99 | if (!reached[w]) { |
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| 100 | bfs_queue.push(w); |
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| 101 | reached.set(w, true); |
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| 102 | b_node_newly_reached=true; |
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| 103 | } else { |
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| 104 | b_node_newly_reached=false; |
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| 105 | } |
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| 106 | } |
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| 107 | } |
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| 108 | } |
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| 109 | return *this; |
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| 110 | } |
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[646] | 111 | /// Returns true iff the algorithm is finished. |
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[602] | 112 | bool finished() const { return bfs_queue.empty(); } |
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| 113 | /// The conversion operator makes for converting the bfs-iterator |
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| 114 | /// to an \c out-edge-iterator. |
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| 115 | ///\bug Edge have to be in HUGO 0.2 |
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| 116 | operator OutEdgeIt() const { return actual_edge; } |
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[646] | 117 | /// Returns if b-node has been reached just now. |
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[602] | 118 | bool isBNodeNewlyReached() const { return b_node_newly_reached; } |
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[646] | 119 | /// Returns if a-node is examined. |
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[602] | 120 | bool isANodeExamined() const { return !(graph->valid(actual_edge)); } |
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[646] | 121 | /// Returns a-node of the actual edge, so does if the edge is invalid. |
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[602] | 122 | Node aNode() const { return bfs_queue.front(); } |
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[646] | 123 | /// \pre The actual edge have to be valid. |
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[602] | 124 | Node bNode() const { return graph->bNode(actual_edge); } |
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[615] | 125 | /// Guess what? |
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[650] | 126 | /// \deprecated |
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[602] | 127 | const ReachedMap& getReachedMap() const { return reached; } |
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[615] | 128 | /// Guess what? |
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[650] | 129 | /// \deprecated |
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[602] | 130 | const std::queue<Node>& getBfsQueue() const { return bfs_queue; } |
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[615] | 131 | }; |
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[602] | 132 | |
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| 133 | /// Bfs searches for the nodes wich are not marked in |
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| 134 | /// \c reached_map |
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| 135 | /// Reached have to work as a read-write bool Node-map, |
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[650] | 136 | /// Pred is a write edge node-map and |
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| 137 | /// Dist is a read-write node-map of integral value, have to be. |
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[615] | 138 | /// \ingroup galgs |
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[602] | 139 | template <typename Graph, |
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| 140 | typename ReachedMap=typename Graph::template NodeMap<bool>, |
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| 141 | typename PredMap |
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| 142 | =typename Graph::template NodeMap<typename Graph::Edge>, |
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| 143 | typename DistMap=typename Graph::template NodeMap<int> > |
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| 144 | class Bfs : public BfsIterator<Graph, ReachedMap> { |
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| 145 | typedef BfsIterator<Graph, ReachedMap> Parent; |
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| 146 | protected: |
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| 147 | typedef typename Parent::Node Node; |
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| 148 | PredMap& pred; |
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| 149 | DistMap& dist; |
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| 150 | public: |
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| 151 | /// The algorithm will search in a bfs order for |
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| 152 | /// the nodes which are \c false initially. |
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| 153 | /// The constructor makes no initial changes on the maps. |
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[671] | 154 | Bfs<Graph, ReachedMap, PredMap, DistMap>(const Graph& _graph, ReachedMap& _reached, PredMap& _pred, DistMap& _dist) : |
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| 155 | BfsIterator<Graph, ReachedMap>(_graph, _reached), |
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| 156 | pred(_pred), dist(_dist) { } |
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[602] | 157 | /// \c s is marked to be reached and pushed in the bfs queue. |
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| 158 | /// If the queue is empty, then the first out-edge is processed. |
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| 159 | /// If \c s was not marked previously, then |
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| 160 | /// in addition its pred is set to be \c INVALID, and dist to \c 0. |
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| 161 | /// if \c s was marked previuosly, then it is simply pushed. |
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| 162 | void push(Node s) { |
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| 163 | if (this->reached[s]) { |
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| 164 | Parent::pushAndSetReached(s); |
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| 165 | } else { |
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| 166 | Parent::pushAndSetReached(s); |
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| 167 | pred.set(s, INVALID); |
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| 168 | dist.set(s, 0); |
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| 169 | } |
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| 170 | } |
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| 171 | /// A bfs is processed from \c s. |
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| 172 | void run(Node s) { |
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| 173 | push(s); |
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| 174 | while (!this->finished()) this->operator++(); |
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| 175 | } |
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| 176 | /// Beside the bfs iteration, \c pred and \dist are saved in a |
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| 177 | /// newly reached node. |
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[604] | 178 | Bfs<Graph, ReachedMap, PredMap, DistMap>& operator++() { |
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[602] | 179 | Parent::operator++(); |
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| 180 | if (this->graph->valid(this->actual_edge) && this->b_node_newly_reached) |
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| 181 | { |
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| 182 | pred.set(this->bNode(), this->actual_edge); |
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| 183 | dist.set(this->bNode(), dist[this->aNode()]); |
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| 184 | } |
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| 185 | return *this; |
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| 186 | } |
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[615] | 187 | /// Guess what? |
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[650] | 188 | /// \deprecated |
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[602] | 189 | const PredMap& getPredMap() const { return pred; } |
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[615] | 190 | /// Guess what? |
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[650] | 191 | /// \deprecated |
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[602] | 192 | const DistMap& getDistMap() const { return dist; } |
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| 193 | }; |
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| 194 | |
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| 195 | /// Dfs searches for the nodes wich are not marked in |
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| 196 | /// \c reached_map |
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| 197 | /// Reached have to be a read-write bool Node-map. |
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[615] | 198 | /// \ingroup galgs |
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[602] | 199 | template <typename Graph, /*typename OutEdgeIt,*/ |
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| 200 | typename ReachedMap/*=typename Graph::NodeMap<bool>*/ > |
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| 201 | class DfsIterator { |
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| 202 | protected: |
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| 203 | typedef typename Graph::Node Node; |
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| 204 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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| 205 | const Graph* graph; |
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| 206 | std::stack<OutEdgeIt> dfs_stack; |
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| 207 | bool b_node_newly_reached; |
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| 208 | OutEdgeIt actual_edge; |
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| 209 | Node actual_node; |
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| 210 | ReachedMap& reached; |
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| 211 | bool own_reached_map; |
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| 212 | public: |
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| 213 | /// In that constructor \c _reached have to be a reference |
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[650] | 214 | /// for a bool node-map. The algorithm will search in a dfs order for |
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[602] | 215 | /// the nodes which are \c false initially |
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| 216 | DfsIterator(const Graph& _graph, ReachedMap& _reached) : |
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| 217 | graph(&_graph), reached(_reached), |
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| 218 | own_reached_map(false) { } |
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| 219 | /// The same as above, but the map of reached nodes is |
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| 220 | /// constructed dynamically |
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| 221 | /// to everywhere false. |
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| 222 | DfsIterator(const Graph& _graph) : |
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| 223 | graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), |
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| 224 | own_reached_map(true) { } |
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| 225 | ~DfsIterator() { if (own_reached_map) delete &reached; } |
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| 226 | /// This method markes s reached and first out-edge is processed. |
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| 227 | void pushAndSetReached(Node s) { |
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| 228 | actual_node=s; |
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| 229 | reached.set(s, true); |
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| 230 | OutEdgeIt e; |
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| 231 | graph->first(e, s); |
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| 232 | dfs_stack.push(e); |
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| 233 | } |
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| 234 | /// As \c DfsIterator<Graph, ReachedMap> works as an edge-iterator, |
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| 235 | /// its \c operator++() iterates on the edges in a dfs order. |
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| 236 | DfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& |
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| 237 | operator++() { |
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| 238 | actual_edge=dfs_stack.top(); |
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| 239 | //actual_node=G.aNode(actual_edge); |
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| 240 | if (graph->valid(actual_edge)/*.valid()*/) { |
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| 241 | Node w=graph->bNode(actual_edge); |
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| 242 | actual_node=w; |
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| 243 | if (!reached[w]) { |
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| 244 | OutEdgeIt e; |
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| 245 | graph->first(e, w); |
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| 246 | dfs_stack.push(e); |
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| 247 | reached.set(w, true); |
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| 248 | b_node_newly_reached=true; |
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| 249 | } else { |
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| 250 | actual_node=graph->aNode(actual_edge); |
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| 251 | graph->next(dfs_stack.top()); |
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| 252 | b_node_newly_reached=false; |
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| 253 | } |
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| 254 | } else { |
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| 255 | //actual_node=G.aNode(dfs_stack.top()); |
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| 256 | dfs_stack.pop(); |
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| 257 | } |
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| 258 | return *this; |
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| 259 | } |
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[646] | 260 | /// Returns true iff the algorithm is finished. |
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[602] | 261 | bool finished() const { return dfs_stack.empty(); } |
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[646] | 262 | /// The conversion operator makes for converting the bfs-iterator |
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| 263 | /// to an \c out-edge-iterator. |
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| 264 | ///\bug Edge have to be in HUGO 0.2 |
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[602] | 265 | operator OutEdgeIt() const { return actual_edge; } |
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[646] | 266 | /// Returns if b-node has been reached just now. |
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[602] | 267 | bool isBNodeNewlyReached() const { return b_node_newly_reached; } |
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[646] | 268 | /// Returns if a-node is examined. |
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[602] | 269 | bool isANodeExamined() const { return !(graph->valid(actual_edge)); } |
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[646] | 270 | /// Returns a-node of the actual edge, so does if the edge is invalid. |
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[602] | 271 | Node aNode() const { return actual_node; /*FIXME*/} |
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[646] | 272 | /// Returns b-node of the actual edge. |
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| 273 | /// \pre The actual edge have to be valid. |
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[602] | 274 | Node bNode() const { return graph->bNode(actual_edge); } |
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[615] | 275 | /// Guess what? |
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[650] | 276 | /// \deprecated |
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[602] | 277 | const ReachedMap& getReachedMap() const { return reached; } |
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[615] | 278 | /// Guess what? |
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[650] | 279 | /// \deprecated |
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[602] | 280 | const std::stack<OutEdgeIt>& getDfsStack() const { return dfs_stack; } |
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| 281 | }; |
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| 282 | |
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| 283 | /// Dfs searches for the nodes wich are not marked in |
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| 284 | /// \c reached_map |
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[650] | 285 | /// Reached is a read-write bool node-map, |
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| 286 | /// Pred is a write node-map, have to be. |
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[615] | 287 | /// \ingroup galgs |
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[602] | 288 | template <typename Graph, |
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| 289 | typename ReachedMap=typename Graph::template NodeMap<bool>, |
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| 290 | typename PredMap |
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| 291 | =typename Graph::template NodeMap<typename Graph::Edge> > |
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| 292 | class Dfs : public DfsIterator<Graph, ReachedMap> { |
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| 293 | typedef DfsIterator<Graph, ReachedMap> Parent; |
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| 294 | protected: |
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| 295 | typedef typename Parent::Node Node; |
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| 296 | PredMap& pred; |
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| 297 | public: |
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| 298 | /// The algorithm will search in a dfs order for |
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| 299 | /// the nodes which are \c false initially. |
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| 300 | /// The constructor makes no initial changes on the maps. |
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[671] | 301 | Dfs<Graph, ReachedMap, PredMap>(const Graph& _graph, ReachedMap& _reached, PredMap& _pred) : DfsIterator<Graph, ReachedMap>(_graph, _reached), pred(_pred) { } |
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[602] | 302 | /// \c s is marked to be reached and pushed in the bfs queue. |
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| 303 | /// If the queue is empty, then the first out-edge is processed. |
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| 304 | /// If \c s was not marked previously, then |
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| 305 | /// in addition its pred is set to be \c INVALID. |
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| 306 | /// if \c s was marked previuosly, then it is simply pushed. |
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| 307 | void push(Node s) { |
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| 308 | if (this->reached[s]) { |
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| 309 | Parent::pushAndSetReached(s); |
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| 310 | } else { |
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| 311 | Parent::pushAndSetReached(s); |
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| 312 | pred.set(s, INVALID); |
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| 313 | } |
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| 314 | } |
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| 315 | /// A bfs is processed from \c s. |
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| 316 | void run(Node s) { |
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| 317 | push(s); |
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| 318 | while (!this->finished()) this->operator++(); |
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| 319 | } |
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| 320 | /// Beside the dfs iteration, \c pred is saved in a |
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| 321 | /// newly reached node. |
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[604] | 322 | Dfs<Graph, ReachedMap, PredMap>& operator++() { |
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[602] | 323 | Parent::operator++(); |
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| 324 | if (this->graph->valid(this->actual_edge) && this->b_node_newly_reached) |
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| 325 | { |
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| 326 | pred.set(this->bNode(), this->actual_edge); |
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| 327 | } |
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| 328 | return *this; |
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| 329 | } |
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[615] | 330 | /// Guess what? |
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[650] | 331 | /// \deprecated |
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[602] | 332 | const PredMap& getPredMap() const { return pred; } |
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| 333 | }; |
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| 334 | |
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| 335 | |
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| 336 | } // namespace hugo |
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| 337 | |
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| 338 | #endif //HUGO_BFS_DFS_H |
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