[301] | 1 | // -*- c++ -*- |
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| 2 | #ifndef HUGO_BFS_ITERATOR_H |
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| 3 | #define HUGO_BFS_ITERATOR_H |
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| 4 | |
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| 5 | #include <queue> |
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| 6 | #include <stack> |
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| 7 | #include <utility> |
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| 8 | |
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| 9 | namespace hugo { |
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| 10 | |
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[303] | 11 | template <typename Graph, /*typename OutEdgeIt,*/ |
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| 12 | typename ReachedMap/*=typename Graph::NodeMap<bool>*/ > |
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[360] | 13 | class BfsIterator { |
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[303] | 14 | protected: |
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| 15 | typedef typename Graph::Node Node; |
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| 16 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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| 17 | const Graph* graph; |
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[301] | 18 | std::queue<Node> bfs_queue; |
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| 19 | ReachedMap& reached; |
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| 20 | bool b_node_newly_reached; |
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| 21 | OutEdgeIt actual_edge; |
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| 22 | bool own_reached_map; |
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| 23 | public: |
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[360] | 24 | BfsIterator(const Graph& _graph, ReachedMap& _reached) : |
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[303] | 25 | graph(&_graph), reached(_reached), |
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[301] | 26 | own_reached_map(false) { } |
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[360] | 27 | BfsIterator(const Graph& _graph) : |
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[303] | 28 | graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), |
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[301] | 29 | own_reached_map(true) { } |
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[360] | 30 | ~BfsIterator() { if (own_reached_map) delete &reached; } |
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[409] | 31 | //s is marcked reached. |
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| 32 | //if the queue is empty, then the its is pushed ant the first OutEdgeIt is processe. |
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| 33 | //is the queue is not empty, then is it pushed. |
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[301] | 34 | void pushAndSetReached(Node s) { |
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| 35 | reached.set(s, true); |
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| 36 | if (bfs_queue.empty()) { |
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| 37 | bfs_queue.push(s); |
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[303] | 38 | graph->first(actual_edge, s); |
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| 39 | if (graph->valid(actual_edge)) { |
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| 40 | Node w=graph->bNode(actual_edge); |
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| 41 | if (!reached[w]) { |
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[301] | 42 | bfs_queue.push(w); |
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| 43 | reached.set(w, true); |
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| 44 | b_node_newly_reached=true; |
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| 45 | } else { |
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| 46 | b_node_newly_reached=false; |
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| 47 | } |
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| 48 | } |
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| 49 | } else { |
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| 50 | bfs_queue.push(s); |
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| 51 | } |
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| 52 | } |
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[360] | 53 | BfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& |
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[301] | 54 | operator++() { |
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[303] | 55 | if (graph->valid(actual_edge)) { |
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| 56 | graph->next(actual_edge); |
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| 57 | if (graph->valid(actual_edge)) { |
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| 58 | Node w=graph->bNode(actual_edge); |
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| 59 | if (!reached[w]) { |
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[301] | 60 | bfs_queue.push(w); |
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| 61 | reached.set(w, true); |
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| 62 | b_node_newly_reached=true; |
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| 63 | } else { |
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| 64 | b_node_newly_reached=false; |
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| 65 | } |
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| 66 | } |
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| 67 | } else { |
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| 68 | bfs_queue.pop(); |
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| 69 | if (!bfs_queue.empty()) { |
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[303] | 70 | graph->first(actual_edge, bfs_queue.front()); |
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| 71 | if (graph->valid(actual_edge)) { |
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| 72 | Node w=graph->bNode(actual_edge); |
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| 73 | if (!reached[w]) { |
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[301] | 74 | bfs_queue.push(w); |
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| 75 | reached.set(w, true); |
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| 76 | b_node_newly_reached=true; |
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| 77 | } else { |
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| 78 | b_node_newly_reached=false; |
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| 79 | } |
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| 80 | } |
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| 81 | } |
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| 82 | } |
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| 83 | return *this; |
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| 84 | } |
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| 85 | bool finished() const { return bfs_queue.empty(); } |
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[409] | 86 | operator OutEdgeIt() const { return actual_edge; } |
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[301] | 87 | bool isBNodeNewlyReached() const { return b_node_newly_reached; } |
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[303] | 88 | bool isANodeExamined() const { return !(graph->valid(actual_edge)); } |
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[301] | 89 | Node aNode() const { return bfs_queue.front(); } |
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[303] | 90 | Node bNode() const { return graph->bNode(actual_edge); } |
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[301] | 91 | const ReachedMap& getReachedMap() const { return reached; } |
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| 92 | const std::queue<Node>& getBfsQueue() const { return bfs_queue; } |
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| 93 | }; |
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| 94 | |
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[409] | 95 | /// Bfs searches from s for the nodes wich are not marked in |
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| 96 | /// reachedmap |
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| 97 | template <typename Graph, |
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| 98 | typename ReachedMap=typename Graph::template NodeMap<bool>, |
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| 99 | typename PredMap |
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| 100 | =typename Graph::template NodeMap<typename Graph::Edge>, |
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| 101 | typename DistMap=typename Graph::template NodeMap<int> > |
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| 102 | class Bfs : public BfsIterator<Graph, ReachedMap> { |
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| 103 | typedef BfsIterator<Graph, ReachedMap> Parent; |
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| 104 | protected: |
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| 105 | typedef typename Parent::Node Node; |
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| 106 | PredMap& pred; |
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| 107 | DistMap& dist; |
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| 108 | public: |
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| 109 | 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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| 110 | //s is marked to be reached and pushed in the bfs queue. |
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| 111 | //if the queue is empty, then the first out-edge is processed |
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| 112 | //If s was not marked previously, then |
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| 113 | //in addition its pred is set to be INVALID, and dist to 0. |
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| 114 | //if s was marked previuosly, then it is simply pushed. |
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| 115 | void push(Node s) { |
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| 116 | if (this->reached[s]) { |
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| 117 | Parent::pushAndSetReached(s); |
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| 118 | } else { |
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| 119 | Parent::pushAndSetReached(s); |
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| 120 | pred.set(s, INVALID); |
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| 121 | dist.set(s, 0); |
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| 122 | } |
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| 123 | } |
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| 124 | void run(Node s) { |
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| 125 | push(s); |
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| 126 | while (!this->finished()) this->operator++(); |
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| 127 | } |
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| 128 | Bfs<Graph, ReachedMap, PredMap, DistMap> operator++() { |
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| 129 | Parent::operator++(); |
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[414] | 130 | if (this->graph->valid(this->actual_edge) && this->b_node_newly_reached) { |
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[409] | 131 | pred.set(s, actual_edge); |
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| 132 | dist.set(s, dist[this->aNode()]); |
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| 133 | } |
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| 134 | return *this; |
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| 135 | } |
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| 136 | const PredMap& getPredMap() const { return pred; } |
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| 137 | const DistMap& getDistMap() const { return dist; } |
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| 138 | }; |
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| 139 | |
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[303] | 140 | template <typename Graph, /*typename OutEdgeIt,*/ |
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| 141 | typename ReachedMap/*=typename Graph::NodeMap<bool>*/ > |
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[360] | 142 | class DfsIterator { |
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[303] | 143 | protected: |
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| 144 | typedef typename Graph::Node Node; |
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| 145 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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| 146 | const Graph* graph; |
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[301] | 147 | std::stack<OutEdgeIt> dfs_stack; |
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| 148 | bool b_node_newly_reached; |
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| 149 | OutEdgeIt actual_edge; |
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| 150 | Node actual_node; |
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| 151 | ReachedMap& reached; |
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| 152 | bool own_reached_map; |
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| 153 | public: |
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[360] | 154 | DfsIterator(const Graph& _graph, ReachedMap& _reached) : |
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[303] | 155 | graph(&_graph), reached(_reached), |
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[301] | 156 | own_reached_map(false) { } |
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[360] | 157 | DfsIterator(const Graph& _graph) : |
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[303] | 158 | graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), |
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[301] | 159 | own_reached_map(true) { } |
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[360] | 160 | ~DfsIterator() { if (own_reached_map) delete &reached; } |
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[301] | 161 | void pushAndSetReached(Node s) { |
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| 162 | actual_node=s; |
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| 163 | reached.set(s, true); |
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| 164 | OutEdgeIt e; |
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[303] | 165 | graph->first(e, s); |
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[301] | 166 | dfs_stack.push(e); |
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| 167 | } |
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[360] | 168 | DfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& |
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[301] | 169 | operator++() { |
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| 170 | actual_edge=dfs_stack.top(); |
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| 171 | //actual_node=G.aNode(actual_edge); |
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[303] | 172 | if (graph->valid(actual_edge)/*.valid()*/) { |
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| 173 | Node w=graph->bNode(actual_edge); |
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[301] | 174 | actual_node=w; |
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[303] | 175 | if (!reached[w]) { |
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[301] | 176 | OutEdgeIt e; |
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[303] | 177 | graph->first(e, w); |
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[301] | 178 | dfs_stack.push(e); |
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| 179 | reached.set(w, true); |
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| 180 | b_node_newly_reached=true; |
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| 181 | } else { |
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[303] | 182 | actual_node=graph->aNode(actual_edge); |
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| 183 | graph->next(dfs_stack.top()); |
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[301] | 184 | b_node_newly_reached=false; |
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| 185 | } |
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| 186 | } else { |
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| 187 | //actual_node=G.aNode(dfs_stack.top()); |
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| 188 | dfs_stack.pop(); |
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| 189 | } |
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| 190 | return *this; |
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| 191 | } |
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| 192 | bool finished() const { return dfs_stack.empty(); } |
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[409] | 193 | operator OutEdgeIt() const { return actual_edge; } |
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[301] | 194 | bool isBNodeNewlyReached() const { return b_node_newly_reached; } |
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[303] | 195 | bool isANodeExamined() const { return !(graph->valid(actual_edge)); } |
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[301] | 196 | Node aNode() const { return actual_node; /*FIXME*/} |
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[389] | 197 | Node bNode() const { return graph->bNode(actual_edge); } |
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[301] | 198 | const ReachedMap& getReachedMap() const { return reached; } |
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| 199 | const std::stack<OutEdgeIt>& getDfsStack() const { return dfs_stack; } |
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| 200 | }; |
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| 201 | |
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| 202 | } // namespace hugo |
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| 203 | |
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| 204 | #endif //HUGO_BFS_ITERATOR_H |
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