marci@602: // -*- c++ -*-
marci@602: #ifndef HUGO_BFS_DFS_H
marci@602: #define HUGO_BFS_DFS_H
marci@602: 
marci@615: /// \ingroup galgs
marci@615: /// \file
marci@615: /// \brief Bfs and dfs iterators.
marci@604: ///
marci@615: /// This file contains bfs and dfs iterator classes.
marci@604: ///
marci@615: // /// \author Marton Makai
marci@604: 
marci@602: #include <queue>
marci@602: #include <stack>
marci@602: #include <utility>
marci@602: 
marci@602: #include <hugo/invalid.h>
marci@602: 
marci@602: namespace hugo {
marci@602: 
marci@602:   /// Bfs searches for the nodes wich are not marked in 
marci@602:   /// \c reached_map
marci@650:   /// Reached have to be a read-write bool node-map.
marci@615:   /// \ingroup galgs
marci@602:   template <typename Graph, /*typename OutEdgeIt,*/ 
marci@602: 	    typename ReachedMap/*=typename Graph::NodeMap<bool>*/ >
marci@602:   class BfsIterator {
marci@602:   protected:
marci@602:     typedef typename Graph::Node Node;
marci@777:     typedef typename Graph::Edge Edge;
marci@602:     typedef typename Graph::OutEdgeIt OutEdgeIt;
marci@602:     const Graph* graph;
marci@602:     std::queue<Node> bfs_queue;
marci@602:     ReachedMap& reached;
marci@602:     bool b_node_newly_reached;
marci@777:     Edge actual_edge;
marci@602:     bool own_reached_map;
marci@602:   public:
marci@602:     /// In that constructor \c _reached have to be a reference 
marci@650:     /// for a bool bode-map. The algorithm will search for the 
marci@650:     /// initially \c false nodes 
marci@650:     /// in a bfs order.
marci@602:     BfsIterator(const Graph& _graph, ReachedMap& _reached) : 
marci@602:       graph(&_graph), reached(_reached), 
marci@602:       own_reached_map(false) { }
marci@602:     /// The same as above, but the map storing the reached nodes 
marci@602:     /// is constructed dynamically to everywhere false.
marci@650:     /// \deprecated
marci@602:     BfsIterator(const Graph& _graph) : 
marci@602:       graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), 
marci@602:       own_reached_map(true) { }
marci@604:     /// The map storing the reached nodes have to be destroyed if 
marci@602:     /// it was constructed dynamically
marci@602:     ~BfsIterator() { if (own_reached_map) delete &reached; }
marci@602:     /// This method markes \c s reached.
marci@602:     /// If the queue is empty, then \c s is pushed in the bfs queue 
marci@602:     /// and the first out-edge is processed.
marci@602:     /// If the queue is not empty, then \c s is simply pushed.
marci@777:     BfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& pushAndSetReached(Node s) { 
marci@602:       reached.set(s, true);
marci@602:       if (bfs_queue.empty()) {
marci@602: 	bfs_queue.push(s);
marci@777: 	actual_edge=OutEdgeIt(*graph, s);
marci@777: 	//graph->first(actual_edge, s);
alpar@774: 	if (actual_edge!=INVALID) { 
alpar@774: 	  Node w=graph->head(actual_edge);
marci@602: 	  if (!reached[w]) {
marci@602: 	    bfs_queue.push(w);
marci@602: 	    reached.set(w, true);
marci@602: 	    b_node_newly_reached=true;
marci@602: 	  } else {
marci@602: 	    b_node_newly_reached=false;
marci@602: 	  }
marci@602: 	} 
marci@602:       } else {
marci@602: 	bfs_queue.push(s);
marci@602:       }
marci@777:       return *this;
marci@602:     }
marci@602:     /// As \c BfsIterator<Graph, ReachedMap> works as an edge-iterator, 
marci@602:     /// its \c operator++() iterates on the edges in a bfs order.
marci@602:     BfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& 
marci@602:     operator++() { 
alpar@774:       if (actual_edge!=INVALID) { 
marci@777: 	actual_edge=++OutEdgeIt(*graph, actual_edge);
marci@777: 	//++actual_edge;
alpar@774: 	if (actual_edge!=INVALID) {
alpar@774: 	  Node w=graph->head(actual_edge);
marci@602: 	  if (!reached[w]) {
marci@602: 	    bfs_queue.push(w);
marci@602: 	    reached.set(w, true);
marci@602: 	    b_node_newly_reached=true;
marci@602: 	  } else {
marci@602: 	    b_node_newly_reached=false;
marci@602: 	  }
marci@602: 	}
marci@602:       } else {
marci@602: 	bfs_queue.pop(); 
marci@602: 	if (!bfs_queue.empty()) {
marci@777: 	  actual_edge=OutEdgeIt(*graph, bfs_queue.front());
marci@777: 	  //graph->first(actual_edge, bfs_queue.front());
alpar@774: 	  if (actual_edge!=INVALID) {
alpar@774: 	    Node w=graph->head(actual_edge);
marci@602: 	    if (!reached[w]) {
marci@602: 	      bfs_queue.push(w);
marci@602: 	      reached.set(w, true);
marci@602: 	      b_node_newly_reached=true;
marci@602: 	    } else {
marci@602: 	      b_node_newly_reached=false;
marci@602: 	    }
marci@602: 	  }
marci@602: 	}
marci@602:       }
marci@602:       return *this;
marci@602:     }
marci@646:     /// Returns true iff the algorithm is finished.
marci@602:     bool finished() const { return bfs_queue.empty(); }
marci@602:     /// The conversion operator makes for converting the bfs-iterator 
marci@602:     /// to an \c out-edge-iterator.
marci@602:     ///\bug Edge have to be in HUGO 0.2
marci@777:     operator Edge() const { return actual_edge; }
marci@646:     /// Returns if b-node has been reached just now.
marci@602:     bool isBNodeNewlyReached() const { return b_node_newly_reached; }
marci@646:     /// Returns if a-node is examined.
alpar@774:     bool isANodeExamined() const { return actual_edge==INVALID; }
marci@646:     /// Returns a-node of the actual edge, so does if the edge is invalid.
marci@777:     Node tail() const { return bfs_queue.front(); }
marci@646:     /// \pre The actual edge have to be valid.
marci@777:     Node head() const { return graph->head(actual_edge); }
marci@615:     /// Guess what?
marci@650:     /// \deprecated 
marci@602:     const ReachedMap& getReachedMap() const { return reached; }
marci@615:     /// Guess what?
marci@650:     /// \deprecated
marci@602:     const std::queue<Node>& getBfsQueue() const { return bfs_queue; }
marci@615:   };
marci@602: 
marci@602:   /// Bfs searches for the nodes wich are not marked in 
marci@602:   /// \c reached_map
marci@602:   /// Reached have to work as a read-write bool Node-map, 
marci@650:   /// Pred is a write edge node-map and
marci@650:   /// Dist is a read-write node-map of integral value, have to be. 
marci@615:   /// \ingroup galgs
marci@602:   template <typename Graph, 
marci@602: 	    typename ReachedMap=typename Graph::template NodeMap<bool>, 
marci@602: 	    typename PredMap
marci@602: 	    =typename Graph::template NodeMap<typename Graph::Edge>, 
marci@602: 	    typename DistMap=typename Graph::template NodeMap<int> > 
marci@602:   class Bfs : public BfsIterator<Graph, ReachedMap> {
marci@602:     typedef BfsIterator<Graph, ReachedMap> Parent;
marci@602:   protected:
marci@602:     typedef typename Parent::Node Node;
marci@602:     PredMap& pred;
marci@602:     DistMap& dist;
marci@602:   public:
marci@602:     /// The algorithm will search in a bfs order for 
marci@602:     /// the nodes which are \c false initially. 
marci@602:     /// The constructor makes no initial changes on the maps.
athos@671:     Bfs<Graph, ReachedMap, PredMap, DistMap>(const Graph& _graph, ReachedMap& _reached, PredMap& _pred, DistMap& _dist) : 
athos@671:       BfsIterator<Graph, ReachedMap>(_graph, _reached), 
athos@671:       pred(_pred), dist(_dist) { }
marci@602:     /// \c s is marked to be reached and pushed in the bfs queue.
marci@602:     /// If the queue is empty, then the first out-edge is processed.
marci@602:     /// If \c s was not marked previously, then 
marci@602:     /// in addition its pred is set to be \c INVALID, and dist to \c 0. 
marci@602:     /// if \c s was marked previuosly, then it is simply pushed.
marci@777:     Bfs<Graph, ReachedMap, PredMap, DistMap>& push(Node s) { 
marci@602:       if (this->reached[s]) {
marci@602: 	Parent::pushAndSetReached(s);
marci@602:       } else {
marci@602: 	Parent::pushAndSetReached(s);
marci@602: 	pred.set(s, INVALID);
marci@602: 	dist.set(s, 0);
marci@602:       }
marci@777:       return *this;
marci@602:     }
marci@602:     /// A bfs is processed from \c s.
marci@777:     Bfs<Graph, ReachedMap, PredMap, DistMap>& run(Node s) {
marci@602:       push(s);
marci@602:       while (!this->finished()) this->operator++();
marci@777:       return *this;
marci@602:     }
marci@602:     /// Beside the bfs iteration, \c pred and \dist are saved in a 
marci@602:     /// newly reached node. 
marci@604:     Bfs<Graph, ReachedMap, PredMap, DistMap>& operator++() {
marci@602:       Parent::operator++();
marci@602:       if (this->graph->valid(this->actual_edge) && this->b_node_newly_reached) 
marci@602:       {
marci@777: 	pred.set(this->head(), this->actual_edge);
marci@777: 	dist.set(this->head(), dist[this->tail()]);
marci@602:       }
marci@602:       return *this;
marci@602:     }
marci@615:     /// Guess what?
marci@650:     /// \deprecated 
marci@602:     const PredMap& getPredMap() const { return pred; }
marci@615:     /// Guess what?
marci@650:     /// \deprecated
marci@602:     const DistMap& getDistMap() const { return dist; }
marci@602:   };
marci@602: 
marci@602:   /// Dfs searches for the nodes wich are not marked in 
marci@602:   /// \c reached_map
marci@602:   /// Reached have to be a read-write bool Node-map.
marci@615:   /// \ingroup galgs
marci@602:   template <typename Graph, /*typename OutEdgeIt,*/ 
marci@602: 	    typename ReachedMap/*=typename Graph::NodeMap<bool>*/ >
marci@602:   class DfsIterator {
marci@602:   protected:
marci@602:     typedef typename Graph::Node Node;
marci@777:     typedef typename Graph::Edge Edge;
marci@602:     typedef typename Graph::OutEdgeIt OutEdgeIt;
marci@602:     const Graph* graph;
marci@602:     std::stack<OutEdgeIt> dfs_stack;
marci@602:     bool b_node_newly_reached;
marci@777:     Edge actual_edge;
marci@602:     Node actual_node;
marci@602:     ReachedMap& reached;
marci@602:     bool own_reached_map;
marci@602:   public:
marci@602:     /// In that constructor \c _reached have to be a reference 
marci@650:     /// for a bool node-map. The algorithm will search in a dfs order for 
marci@602:     /// the nodes which are \c false initially
marci@602:     DfsIterator(const Graph& _graph, ReachedMap& _reached) : 
marci@602:       graph(&_graph), reached(_reached), 
marci@602:       own_reached_map(false) { }
marci@602:     /// The same as above, but the map of reached nodes is 
marci@602:     /// constructed dynamically 
marci@602:     /// to everywhere false.
marci@602:     DfsIterator(const Graph& _graph) : 
marci@602:       graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), 
marci@602:       own_reached_map(true) { }
marci@602:     ~DfsIterator() { if (own_reached_map) delete &reached; }
marci@602:     /// This method markes s reached and first out-edge is processed.
marci@777:     DfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& pushAndSetReached(Node s) { 
marci@602:       actual_node=s;
marci@602:       reached.set(s, true);
marci@777:       OutEdgeIt e(*graph, s);
marci@777:       //graph->first(e, s);
marci@602:       dfs_stack.push(e); 
marci@777:       return *this;
marci@602:     }
marci@602:     /// As \c DfsIterator<Graph, ReachedMap> works as an edge-iterator, 
marci@602:     /// its \c operator++() iterates on the edges in a dfs order.
marci@602:     DfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& 
marci@602:     operator++() { 
marci@602:       actual_edge=dfs_stack.top();
alpar@774:       if (actual_edge!=INVALID/*.valid()*/) { 
alpar@774: 	Node w=graph->head(actual_edge);
marci@602: 	actual_node=w;
marci@602: 	if (!reached[w]) {
marci@777: 	  OutEdgeIt e(*graph, w);
marci@777: 	  //graph->first(e, w);
marci@602: 	  dfs_stack.push(e);
marci@602: 	  reached.set(w, true);
marci@602: 	  b_node_newly_reached=true;
marci@602: 	} else {
alpar@774: 	  actual_node=graph->tail(actual_edge);
alpar@774: 	  ++dfs_stack.top();
marci@602: 	  b_node_newly_reached=false;
marci@602: 	}
marci@602:       } else {
marci@602: 	//actual_node=G.aNode(dfs_stack.top());
marci@602: 	dfs_stack.pop();
marci@602:       }
marci@602:       return *this;
marci@602:     }
marci@646:     /// Returns true iff the algorithm is finished.
marci@602:     bool finished() const { return dfs_stack.empty(); }
marci@646:     /// The conversion operator makes for converting the bfs-iterator 
marci@646:     /// to an \c out-edge-iterator.
marci@646:     ///\bug Edge have to be in HUGO 0.2
marci@777:     operator Edge() const { return actual_edge; }
marci@646:     /// Returns if b-node has been reached just now.
marci@602:     bool isBNodeNewlyReached() const { return b_node_newly_reached; }
marci@646:     /// Returns if a-node is examined.
alpar@774:     bool isANodeExamined() const { return actual_edge==INVALID; }
marci@646:     /// Returns a-node of the actual edge, so does if the edge is invalid.
marci@777:     Node tail() const { return actual_node; /*FIXME*/}
marci@646:     /// Returns b-node of the actual edge. 
marci@646:     /// \pre The actual edge have to be valid.
marci@777:     Node head() const { return graph->head(actual_edge); }
marci@615:     /// Guess what?
marci@650:     /// \deprecated
marci@602:     const ReachedMap& getReachedMap() const { return reached; }
marci@615:     /// Guess what?
marci@650:     /// \deprecated
marci@602:     const std::stack<OutEdgeIt>& getDfsStack() const { return dfs_stack; }
marci@602:   };
marci@602: 
marci@602:   /// Dfs searches for the nodes wich are not marked in 
marci@602:   /// \c reached_map
marci@650:   /// Reached is a read-write bool node-map, 
marci@650:   /// Pred is a write node-map, have to be.
marci@615:   /// \ingroup galgs
marci@602:   template <typename Graph, 
marci@602: 	    typename ReachedMap=typename Graph::template NodeMap<bool>, 
marci@602: 	    typename PredMap
marci@602: 	    =typename Graph::template NodeMap<typename Graph::Edge> > 
marci@602:   class Dfs : public DfsIterator<Graph, ReachedMap> {
marci@602:     typedef DfsIterator<Graph, ReachedMap> Parent;
marci@602:   protected:
marci@602:     typedef typename Parent::Node Node;
marci@602:     PredMap& pred;
marci@602:   public:
marci@602:     /// The algorithm will search in a dfs order for 
marci@602:     /// the nodes which are \c false initially. 
marci@602:     /// The constructor makes no initial changes on the maps.
athos@671:     Dfs<Graph, ReachedMap, PredMap>(const Graph& _graph, ReachedMap& _reached, PredMap& _pred) : DfsIterator<Graph, ReachedMap>(_graph, _reached), pred(_pred) { }
marci@602:     /// \c s is marked to be reached and pushed in the bfs queue.
marci@602:     /// If the queue is empty, then the first out-edge is processed.
marci@602:     /// If \c s was not marked previously, then 
marci@602:     /// in addition its pred is set to be \c INVALID. 
marci@602:     /// if \c s was marked previuosly, then it is simply pushed.
marci@777:     Dfs<Graph, ReachedMap, PredMap>& push(Node s) { 
marci@602:       if (this->reached[s]) {
marci@602: 	Parent::pushAndSetReached(s);
marci@602:       } else {
marci@602: 	Parent::pushAndSetReached(s);
marci@602: 	pred.set(s, INVALID);
marci@602:       }
marci@777:       return *this;
marci@602:     }
marci@602:     /// A bfs is processed from \c s.
marci@777:     Dfs<Graph, ReachedMap, PredMap>& run(Node s) {
marci@602:       push(s);
marci@602:       while (!this->finished()) this->operator++();
marci@777:       return *this;
marci@602:     }
marci@602:     /// Beside the dfs iteration, \c pred is saved in a 
marci@602:     /// newly reached node. 
marci@604:     Dfs<Graph, ReachedMap, PredMap>& operator++() {
marci@602:       Parent::operator++();
marci@602:       if (this->graph->valid(this->actual_edge) && this->b_node_newly_reached) 
marci@602:       {
marci@777: 	pred.set(this->head(), this->actual_edge);
marci@602:       }
marci@602:       return *this;
marci@602:     }
marci@615:     /// Guess what?
marci@650:     /// \deprecated
marci@602:     const PredMap& getPredMap() const { return pred; }
marci@602:   };
marci@602: 
marci@602: 
marci@602: } // namespace hugo
marci@602: 
marci@602: #endif //HUGO_BFS_DFS_H