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