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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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*
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* This file is a part of LEMON, a generic C++ optimization library.
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*
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* Copyright (C) 2003-2008
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* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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* (Egervary Research Group on Combinatorial Optimization, EGRES).
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*
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* Permission to use, modify and distribute this software is granted
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* provided that this copyright notice appears in all copies. For
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* precise terms see the accompanying LICENSE file.
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*
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* This software is provided "AS IS" with no warranty of any kind,
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* express or implied, and with no claim as to its suitability for any
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* purpose.
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*
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*/
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#ifndef LEMON_DFS_H
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#define LEMON_DFS_H
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///\ingroup search
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///\file
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///\brief DFS algorithm.
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#include <lemon/list_graph.h>
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#include <lemon/bits/path_dump.h>
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#include <lemon/core.h>
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#include <lemon/error.h>
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#include <lemon/maps.h>
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#include <lemon/path.h>
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namespace lemon {
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///Default traits class of Dfs class.
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///Default traits class of Dfs class.
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///\tparam GR Digraph type.
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template<class GR>
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struct DfsDefaultTraits
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{
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///The type of the digraph the algorithm runs on.
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typedef GR Digraph;
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///\brief The type of the map that stores the predecessor
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///arcs of the %DFS paths.
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///
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///The type of the map that stores the predecessor
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///arcs of the %DFS paths.
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///It must meet the \ref concepts::WriteMap "WriteMap" concept.
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typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
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///Instantiates a PredMap.
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///This function instantiates a PredMap.
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///\param g is the digraph, to which we would like to define the
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///PredMap.
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static PredMap *createPredMap(const Digraph &g)
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{
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return new PredMap(g);
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}
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///The type of the map that indicates which nodes are processed.
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///The type of the map that indicates which nodes are processed.
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///It must meet the \ref concepts::WriteMap "WriteMap" concept.
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typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
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///Instantiates a ProcessedMap.
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///This function instantiates a ProcessedMap.
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///\param g is the digraph, to which
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///we would like to define the ProcessedMap
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#ifdef DOXYGEN
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static ProcessedMap *createProcessedMap(const Digraph &g)
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#else
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static ProcessedMap *createProcessedMap(const Digraph &)
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#endif
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{
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return new ProcessedMap();
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}
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///The type of the map that indicates which nodes are reached.
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///The type of the map that indicates which nodes are reached.
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///It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
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typedef typename Digraph::template NodeMap<bool> ReachedMap;
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///Instantiates a ReachedMap.
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///This function instantiates a ReachedMap.
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///\param g is the digraph, to which
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///we would like to define the ReachedMap.
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static ReachedMap *createReachedMap(const Digraph &g)
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{
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return new ReachedMap(g);
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}
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///The type of the map that stores the distances of the nodes.
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///The type of the map that stores the distances of the nodes.
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///It must meet the \ref concepts::WriteMap "WriteMap" concept.
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typedef typename Digraph::template NodeMap<int> DistMap;
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///Instantiates a DistMap.
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///This function instantiates a DistMap.
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///\param g is the digraph, to which we would like to define the
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///DistMap.
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static DistMap *createDistMap(const Digraph &g)
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{
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return new DistMap(g);
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}
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};
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///%DFS algorithm class.
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///\ingroup search
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///This class provides an efficient implementation of the %DFS algorithm.
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///
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///There is also a \ref dfs() "function-type interface" for the DFS
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///algorithm, which is convenient in the simplier cases and it can be
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///used easier.
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///
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///\tparam GR The type of the digraph the algorithm runs on.
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///The default value is \ref ListDigraph. The value of GR is not used
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///directly by \ref Dfs, it is only passed to \ref DfsDefaultTraits.
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///\tparam TR Traits class to set various data types used by the algorithm.
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///The default traits class is
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///\ref DfsDefaultTraits "DfsDefaultTraits<GR>".
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///See \ref DfsDefaultTraits for the documentation of
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///a Dfs traits class.
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#ifdef DOXYGEN
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template <typename GR,
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typename TR>
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#else
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template <typename GR=ListDigraph,
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typename TR=DfsDefaultTraits<GR> >
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#endif
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class Dfs {
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public:
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///The type of the digraph the algorithm runs on.
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typedef typename TR::Digraph Digraph;
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///\brief The type of the map that stores the predecessor arcs of the
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///DFS paths.
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typedef typename TR::PredMap PredMap;
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///The type of the map that stores the distances of the nodes.
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typedef typename TR::DistMap DistMap;
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///The type of the map that indicates which nodes are reached.
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typedef typename TR::ReachedMap ReachedMap;
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///The type of the map that indicates which nodes are processed.
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typedef typename TR::ProcessedMap ProcessedMap;
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///The type of the paths.
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typedef PredMapPath<Digraph, PredMap> Path;
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///The traits class.
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typedef TR Traits;
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private:
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typedef typename Digraph::Node Node;
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typedef typename Digraph::NodeIt NodeIt;
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typedef typename Digraph::Arc Arc;
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typedef typename Digraph::OutArcIt OutArcIt;
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//Pointer to the underlying digraph.
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const Digraph *G;
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//Pointer to the map of predecessor arcs.
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PredMap *_pred;
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//Indicates if _pred is locally allocated (true) or not.
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bool local_pred;
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//Pointer to the map of distances.
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DistMap *_dist;
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//Indicates if _dist is locally allocated (true) or not.
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bool local_dist;
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//Pointer to the map of reached status of the nodes.
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ReachedMap *_reached;
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//Indicates if _reached is locally allocated (true) or not.
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bool local_reached;
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//Pointer to the map of processed status of the nodes.
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ProcessedMap *_processed;
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//Indicates if _processed is locally allocated (true) or not.
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bool local_processed;
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std::vector<typename Digraph::OutArcIt> _stack;
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int _stack_head;
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//Creates the maps if necessary.
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void create_maps()
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{
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if(!_pred) {
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local_pred = true;
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_pred = Traits::createPredMap(*G);
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}
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if(!_dist) {
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local_dist = true;
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_dist = Traits::createDistMap(*G);
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}
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if(!_reached) {
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local_reached = true;
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_reached = Traits::createReachedMap(*G);
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}
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if(!_processed) {
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local_processed = true;
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_processed = Traits::createProcessedMap(*G);
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}
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}
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protected:
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Dfs() {}
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public:
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typedef Dfs Create;
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///\name Named template parameters
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///@{
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template <class T>
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struct SetPredMapTraits : public Traits {
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typedef T PredMap;
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static PredMap *createPredMap(const Digraph &)
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{
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LEMON_ASSERT(false, "PredMap is not initialized");
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return 0; // ignore warnings
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}
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};
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///\brief \ref named-templ-param "Named parameter" for setting
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///PredMap type.
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///
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///\ref named-templ-param "Named parameter" for setting
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///PredMap type.
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template <class T>
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struct SetPredMap : public Dfs<Digraph, SetPredMapTraits<T> > {
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typedef Dfs<Digraph, SetPredMapTraits<T> > Create;
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};
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template <class T>
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struct SetDistMapTraits : public Traits {
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typedef T DistMap;
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static DistMap *createDistMap(const Digraph &)
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{
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LEMON_ASSERT(false, "DistMap is not initialized");
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return 0; // ignore warnings
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}
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};
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///\brief \ref named-templ-param "Named parameter" for setting
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///DistMap type.
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///
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kpeter@244
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///\ref named-templ-param "Named parameter" for setting
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///DistMap type.
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template <class T>
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struct SetDistMap : public Dfs< Digraph, SetDistMapTraits<T> > {
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typedef Dfs<Digraph, SetDistMapTraits<T> > Create;
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};
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alpar@100
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template <class T>
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struct SetReachedMapTraits : public Traits {
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typedef T ReachedMap;
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static ReachedMap *createReachedMap(const Digraph &)
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{
|
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LEMON_ASSERT(false, "ReachedMap is not initialized");
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return 0; // ignore warnings
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alpar@100
|
264 |
}
|
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};
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alpar@100
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///\brief \ref named-templ-param "Named parameter" for setting
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kpeter@305
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///ReachedMap type.
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///
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kpeter@244
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///\ref named-templ-param "Named parameter" for setting
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kpeter@305
|
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///ReachedMap type.
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template <class T>
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struct SetReachedMap : public Dfs< Digraph, SetReachedMapTraits<T> > {
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typedef Dfs< Digraph, SetReachedMapTraits<T> > Create;
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};
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|
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|
alpar@100
|
276 |
template <class T>
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|
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struct SetProcessedMapTraits : public Traits {
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alpar@100
|
278 |
typedef T ProcessedMap;
|
alpar@209
|
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static ProcessedMap *createProcessedMap(const Digraph &)
|
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|
280 |
{
|
deba@290
|
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LEMON_ASSERT(false, "ProcessedMap is not initialized");
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|
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return 0; // ignore warnings
|
alpar@100
|
283 |
}
|
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|
284 |
};
|
alpar@100
|
285 |
///\brief \ref named-templ-param "Named parameter" for setting
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kpeter@305
|
286 |
///ProcessedMap type.
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alpar@100
|
287 |
///
|
kpeter@244
|
288 |
///\ref named-templ-param "Named parameter" for setting
|
kpeter@305
|
289 |
///ProcessedMap type.
|
alpar@100
|
290 |
template <class T>
|
kpeter@257
|
291 |
struct SetProcessedMap : public Dfs< Digraph, SetProcessedMapTraits<T> > {
|
kpeter@257
|
292 |
typedef Dfs< Digraph, SetProcessedMapTraits<T> > Create;
|
alpar@100
|
293 |
};
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alpar@209
|
294 |
|
kpeter@257
|
295 |
struct SetStandardProcessedMapTraits : public Traits {
|
alpar@100
|
296 |
typedef typename Digraph::template NodeMap<bool> ProcessedMap;
|
kpeter@244
|
297 |
static ProcessedMap *createProcessedMap(const Digraph &g)
|
alpar@100
|
298 |
{
|
kpeter@244
|
299 |
return new ProcessedMap(g);
|
alpar@100
|
300 |
}
|
alpar@100
|
301 |
};
|
kpeter@244
|
302 |
///\brief \ref named-templ-param "Named parameter" for setting
|
kpeter@305
|
303 |
///ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
|
alpar@100
|
304 |
///
|
kpeter@244
|
305 |
///\ref named-templ-param "Named parameter" for setting
|
kpeter@305
|
306 |
///ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
|
kpeter@244
|
307 |
///If you don't set it explicitly, it will be automatically allocated.
|
kpeter@257
|
308 |
struct SetStandardProcessedMap :
|
kpeter@257
|
309 |
public Dfs< Digraph, SetStandardProcessedMapTraits > {
|
kpeter@257
|
310 |
typedef Dfs< Digraph, SetStandardProcessedMapTraits > Create;
|
alpar@100
|
311 |
};
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alpar@209
|
312 |
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alpar@100
|
313 |
///@}
|
alpar@100
|
314 |
|
alpar@209
|
315 |
public:
|
alpar@209
|
316 |
|
alpar@100
|
317 |
///Constructor.
|
alpar@209
|
318 |
|
kpeter@244
|
319 |
///Constructor.
|
kpeter@244
|
320 |
///\param g The digraph the algorithm runs on.
|
kpeter@244
|
321 |
Dfs(const Digraph &g) :
|
kpeter@244
|
322 |
G(&g),
|
alpar@100
|
323 |
_pred(NULL), local_pred(false),
|
alpar@100
|
324 |
_dist(NULL), local_dist(false),
|
alpar@100
|
325 |
_reached(NULL), local_reached(false),
|
alpar@100
|
326 |
_processed(NULL), local_processed(false)
|
alpar@100
|
327 |
{ }
|
alpar@209
|
328 |
|
alpar@100
|
329 |
///Destructor.
|
alpar@209
|
330 |
~Dfs()
|
alpar@100
|
331 |
{
|
alpar@100
|
332 |
if(local_pred) delete _pred;
|
alpar@100
|
333 |
if(local_dist) delete _dist;
|
alpar@100
|
334 |
if(local_reached) delete _reached;
|
alpar@100
|
335 |
if(local_processed) delete _processed;
|
alpar@100
|
336 |
}
|
alpar@100
|
337 |
|
kpeter@244
|
338 |
///Sets the map that stores the predecessor arcs.
|
alpar@100
|
339 |
|
kpeter@244
|
340 |
///Sets the map that stores the predecessor arcs.
|
alpar@100
|
341 |
///If you don't use this function before calling \ref run(),
|
kpeter@244
|
342 |
///it will allocate one. The destructor deallocates this
|
alpar@100
|
343 |
///automatically allocated map, of course.
|
alpar@100
|
344 |
///\return <tt> (*this) </tt>
|
alpar@209
|
345 |
Dfs &predMap(PredMap &m)
|
alpar@100
|
346 |
{
|
alpar@100
|
347 |
if(local_pred) {
|
alpar@209
|
348 |
delete _pred;
|
alpar@209
|
349 |
local_pred=false;
|
alpar@100
|
350 |
}
|
alpar@100
|
351 |
_pred = &m;
|
alpar@100
|
352 |
return *this;
|
alpar@100
|
353 |
}
|
alpar@100
|
354 |
|
kpeter@244
|
355 |
///Sets the map that indicates which nodes are reached.
|
alpar@100
|
356 |
|
kpeter@244
|
357 |
///Sets the map that indicates which nodes are reached.
|
alpar@100
|
358 |
///If you don't use this function before calling \ref run(),
|
kpeter@244
|
359 |
///it will allocate one. The destructor deallocates this
|
kpeter@244
|
360 |
///automatically allocated map, of course.
|
kpeter@244
|
361 |
///\return <tt> (*this) </tt>
|
kpeter@244
|
362 |
Dfs &reachedMap(ReachedMap &m)
|
kpeter@244
|
363 |
{
|
kpeter@244
|
364 |
if(local_reached) {
|
kpeter@244
|
365 |
delete _reached;
|
kpeter@244
|
366 |
local_reached=false;
|
kpeter@244
|
367 |
}
|
kpeter@244
|
368 |
_reached = &m;
|
kpeter@244
|
369 |
return *this;
|
kpeter@244
|
370 |
}
|
kpeter@244
|
371 |
|
kpeter@244
|
372 |
///Sets the map that indicates which nodes are processed.
|
kpeter@244
|
373 |
|
kpeter@244
|
374 |
///Sets the map that indicates which nodes are processed.
|
kpeter@244
|
375 |
///If you don't use this function before calling \ref run(),
|
kpeter@244
|
376 |
///it will allocate one. The destructor deallocates this
|
kpeter@244
|
377 |
///automatically allocated map, of course.
|
kpeter@244
|
378 |
///\return <tt> (*this) </tt>
|
kpeter@244
|
379 |
Dfs &processedMap(ProcessedMap &m)
|
kpeter@244
|
380 |
{
|
kpeter@244
|
381 |
if(local_processed) {
|
kpeter@244
|
382 |
delete _processed;
|
kpeter@244
|
383 |
local_processed=false;
|
kpeter@244
|
384 |
}
|
kpeter@244
|
385 |
_processed = &m;
|
kpeter@244
|
386 |
return *this;
|
kpeter@244
|
387 |
}
|
kpeter@244
|
388 |
|
kpeter@244
|
389 |
///Sets the map that stores the distances of the nodes.
|
kpeter@244
|
390 |
|
kpeter@244
|
391 |
///Sets the map that stores the distances of the nodes calculated by
|
kpeter@244
|
392 |
///the algorithm.
|
kpeter@244
|
393 |
///If you don't use this function before calling \ref run(),
|
kpeter@244
|
394 |
///it will allocate one. The destructor deallocates this
|
alpar@100
|
395 |
///automatically allocated map, of course.
|
alpar@100
|
396 |
///\return <tt> (*this) </tt>
|
alpar@209
|
397 |
Dfs &distMap(DistMap &m)
|
alpar@100
|
398 |
{
|
alpar@100
|
399 |
if(local_dist) {
|
alpar@209
|
400 |
delete _dist;
|
alpar@209
|
401 |
local_dist=false;
|
alpar@100
|
402 |
}
|
alpar@100
|
403 |
_dist = &m;
|
alpar@100
|
404 |
return *this;
|
alpar@100
|
405 |
}
|
alpar@100
|
406 |
|
kpeter@244
|
407 |
public:
|
alpar@100
|
408 |
|
alpar@100
|
409 |
///\name Execution control
|
alpar@100
|
410 |
///The simplest way to execute the algorithm is to use
|
kpeter@244
|
411 |
///one of the member functions called \ref lemon::Dfs::run() "run()".
|
alpar@100
|
412 |
///\n
|
kpeter@244
|
413 |
///If you need more control on the execution, first you must call
|
kpeter@244
|
414 |
///\ref lemon::Dfs::init() "init()", then you can add a source node
|
kpeter@244
|
415 |
///with \ref lemon::Dfs::addSource() "addSource()".
|
kpeter@244
|
416 |
///Finally \ref lemon::Dfs::start() "start()" will perform the
|
kpeter@244
|
417 |
///actual path computation.
|
alpar@100
|
418 |
|
alpar@100
|
419 |
///@{
|
alpar@100
|
420 |
|
alpar@100
|
421 |
///Initializes the internal data structures.
|
alpar@100
|
422 |
|
alpar@100
|
423 |
///Initializes the internal data structures.
|
alpar@100
|
424 |
///
|
alpar@100
|
425 |
void init()
|
alpar@100
|
426 |
{
|
alpar@100
|
427 |
create_maps();
|
alpar@100
|
428 |
_stack.resize(countNodes(*G));
|
alpar@100
|
429 |
_stack_head=-1;
|
alpar@100
|
430 |
for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
|
alpar@209
|
431 |
_pred->set(u,INVALID);
|
alpar@209
|
432 |
_reached->set(u,false);
|
alpar@209
|
433 |
_processed->set(u,false);
|
alpar@100
|
434 |
}
|
alpar@100
|
435 |
}
|
alpar@209
|
436 |
|
alpar@100
|
437 |
///Adds a new source node.
|
alpar@100
|
438 |
|
alpar@100
|
439 |
///Adds a new source node to the set of nodes to be processed.
|
alpar@100
|
440 |
///
|
kpeter@244
|
441 |
///\pre The stack must be empty. (Otherwise the algorithm gives
|
kpeter@244
|
442 |
///false results.)
|
kpeter@244
|
443 |
///
|
kpeter@244
|
444 |
///\warning Distances will be wrong (or at least strange) in case of
|
kpeter@244
|
445 |
///multiple sources.
|
alpar@100
|
446 |
void addSource(Node s)
|
alpar@100
|
447 |
{
|
kpeter@244
|
448 |
LEMON_DEBUG(emptyQueue(), "The stack is not empty.");
|
alpar@100
|
449 |
if(!(*_reached)[s])
|
alpar@209
|
450 |
{
|
alpar@209
|
451 |
_reached->set(s,true);
|
alpar@209
|
452 |
_pred->set(s,INVALID);
|
alpar@209
|
453 |
OutArcIt e(*G,s);
|
alpar@209
|
454 |
if(e!=INVALID) {
|
alpar@209
|
455 |
_stack[++_stack_head]=e;
|
alpar@209
|
456 |
_dist->set(s,_stack_head);
|
alpar@209
|
457 |
}
|
alpar@209
|
458 |
else {
|
alpar@209
|
459 |
_processed->set(s,true);
|
alpar@209
|
460 |
_dist->set(s,0);
|
alpar@209
|
461 |
}
|
alpar@209
|
462 |
}
|
alpar@100
|
463 |
}
|
alpar@209
|
464 |
|
alpar@100
|
465 |
///Processes the next arc.
|
alpar@100
|
466 |
|
alpar@100
|
467 |
///Processes the next arc.
|
alpar@100
|
468 |
///
|
alpar@100
|
469 |
///\return The processed arc.
|
alpar@100
|
470 |
///
|
kpeter@244
|
471 |
///\pre The stack must not be empty.
|
alpar@100
|
472 |
Arc processNextArc()
|
alpar@209
|
473 |
{
|
alpar@100
|
474 |
Node m;
|
alpar@100
|
475 |
Arc e=_stack[_stack_head];
|
alpar@100
|
476 |
if(!(*_reached)[m=G->target(e)]) {
|
alpar@209
|
477 |
_pred->set(m,e);
|
alpar@209
|
478 |
_reached->set(m,true);
|
alpar@209
|
479 |
++_stack_head;
|
alpar@209
|
480 |
_stack[_stack_head] = OutArcIt(*G, m);
|
alpar@209
|
481 |
_dist->set(m,_stack_head);
|
alpar@100
|
482 |
}
|
alpar@100
|
483 |
else {
|
alpar@209
|
484 |
m=G->source(e);
|
alpar@209
|
485 |
++_stack[_stack_head];
|
alpar@100
|
486 |
}
|
alpar@100
|
487 |
while(_stack_head>=0 && _stack[_stack_head]==INVALID) {
|
alpar@209
|
488 |
_processed->set(m,true);
|
alpar@209
|
489 |
--_stack_head;
|
alpar@209
|
490 |
if(_stack_head>=0) {
|
alpar@209
|
491 |
m=G->source(_stack[_stack_head]);
|
alpar@209
|
492 |
++_stack[_stack_head];
|
alpar@209
|
493 |
}
|
alpar@100
|
494 |
}
|
alpar@100
|
495 |
return e;
|
alpar@100
|
496 |
}
|
kpeter@244
|
497 |
|
alpar@100
|
498 |
///Next arc to be processed.
|
alpar@100
|
499 |
|
alpar@100
|
500 |
///Next arc to be processed.
|
alpar@100
|
501 |
///
|
kpeter@244
|
502 |
///\return The next arc to be processed or \c INVALID if the stack
|
kpeter@244
|
503 |
///is empty.
|
kpeter@244
|
504 |
OutArcIt nextArc() const
|
alpar@209
|
505 |
{
|
alpar@100
|
506 |
return _stack_head>=0?_stack[_stack_head]:INVALID;
|
alpar@100
|
507 |
}
|
alpar@100
|
508 |
|
alpar@100
|
509 |
///\brief Returns \c false if there are nodes
|
kpeter@244
|
510 |
///to be processed.
|
alpar@100
|
511 |
///
|
alpar@100
|
512 |
///Returns \c false if there are nodes
|
kpeter@244
|
513 |
///to be processed in the queue (stack).
|
kpeter@244
|
514 |
bool emptyQueue() const { return _stack_head<0; }
|
kpeter@244
|
515 |
|
alpar@100
|
516 |
///Returns the number of the nodes to be processed.
|
alpar@209
|
517 |
|
kpeter@244
|
518 |
///Returns the number of the nodes to be processed in the queue (stack).
|
kpeter@244
|
519 |
int queueSize() const { return _stack_head+1; }
|
alpar@209
|
520 |
|
alpar@100
|
521 |
///Executes the algorithm.
|
alpar@100
|
522 |
|
alpar@100
|
523 |
///Executes the algorithm.
|
alpar@100
|
524 |
///
|
kpeter@244
|
525 |
///This method runs the %DFS algorithm from the root node
|
kpeter@244
|
526 |
///in order to compute the DFS path to each node.
|
alpar@100
|
527 |
///
|
kpeter@244
|
528 |
/// The algorithm computes
|
kpeter@244
|
529 |
///- the %DFS tree,
|
kpeter@244
|
530 |
///- the distance of each node from the root in the %DFS tree.
|
alpar@100
|
531 |
///
|
kpeter@244
|
532 |
///\pre init() must be called and a root node should be
|
kpeter@244
|
533 |
///added with addSource() before using this function.
|
kpeter@244
|
534 |
///
|
kpeter@244
|
535 |
///\note <tt>d.start()</tt> is just a shortcut of the following code.
|
kpeter@244
|
536 |
///\code
|
kpeter@244
|
537 |
/// while ( !d.emptyQueue() ) {
|
kpeter@244
|
538 |
/// d.processNextArc();
|
kpeter@244
|
539 |
/// }
|
kpeter@244
|
540 |
///\endcode
|
alpar@100
|
541 |
void start()
|
alpar@100
|
542 |
{
|
alpar@100
|
543 |
while ( !emptyQueue() ) processNextArc();
|
alpar@100
|
544 |
}
|
alpar@209
|
545 |
|
kpeter@244
|
546 |
///Executes the algorithm until the given target node is reached.
|
alpar@100
|
547 |
|
kpeter@244
|
548 |
///Executes the algorithm until the given target node is reached.
|
alpar@100
|
549 |
///
|
kpeter@244
|
550 |
///This method runs the %DFS algorithm from the root node
|
kpeter@286
|
551 |
///in order to compute the DFS path to \c t.
|
alpar@100
|
552 |
///
|
kpeter@244
|
553 |
///The algorithm computes
|
kpeter@286
|
554 |
///- the %DFS path to \c t,
|
kpeter@286
|
555 |
///- the distance of \c t from the root in the %DFS tree.
|
alpar@100
|
556 |
///
|
kpeter@244
|
557 |
///\pre init() must be called and a root node should be
|
kpeter@244
|
558 |
///added with addSource() before using this function.
|
kpeter@286
|
559 |
void start(Node t)
|
alpar@100
|
560 |
{
|
kpeter@286
|
561 |
while ( !emptyQueue() && G->target(_stack[_stack_head])!=t )
|
alpar@209
|
562 |
processNextArc();
|
alpar@100
|
563 |
}
|
alpar@209
|
564 |
|
alpar@100
|
565 |
///Executes the algorithm until a condition is met.
|
alpar@100
|
566 |
|
alpar@100
|
567 |
///Executes the algorithm until a condition is met.
|
alpar@100
|
568 |
///
|
kpeter@244
|
569 |
///This method runs the %DFS algorithm from the root node
|
kpeter@244
|
570 |
///until an arc \c a with <tt>am[a]</tt> true is found.
|
alpar@100
|
571 |
///
|
kpeter@244
|
572 |
///\param am A \c bool (or convertible) arc map. The algorithm
|
kpeter@244
|
573 |
///will stop when it reaches an arc \c a with <tt>am[a]</tt> true.
|
alpar@100
|
574 |
///
|
kpeter@244
|
575 |
///\return The reached arc \c a with <tt>am[a]</tt> true or
|
alpar@100
|
576 |
///\c INVALID if no such arc was found.
|
alpar@100
|
577 |
///
|
kpeter@244
|
578 |
///\pre init() must be called and a root node should be
|
kpeter@244
|
579 |
///added with addSource() before using this function.
|
kpeter@244
|
580 |
///
|
kpeter@244
|
581 |
///\warning Contrary to \ref Bfs and \ref Dijkstra, \c am is an arc map,
|
alpar@100
|
582 |
///not a node map.
|
kpeter@244
|
583 |
template<class ArcBoolMap>
|
kpeter@244
|
584 |
Arc start(const ArcBoolMap &am)
|
alpar@100
|
585 |
{
|
kpeter@244
|
586 |
while ( !emptyQueue() && !am[_stack[_stack_head]] )
|
alpar@100
|
587 |
processNextArc();
|
alpar@100
|
588 |
return emptyQueue() ? INVALID : _stack[_stack_head];
|
alpar@100
|
589 |
}
|
alpar@100
|
590 |
|
kpeter@286
|
591 |
///Runs the algorithm from the given source node.
|
alpar@209
|
592 |
|
kpeter@244
|
593 |
///This method runs the %DFS algorithm from node \c s
|
kpeter@244
|
594 |
///in order to compute the DFS path to each node.
|
alpar@100
|
595 |
///
|
kpeter@244
|
596 |
///The algorithm computes
|
kpeter@244
|
597 |
///- the %DFS tree,
|
kpeter@244
|
598 |
///- the distance of each node from the root in the %DFS tree.
|
kpeter@244
|
599 |
///
|
kpeter@244
|
600 |
///\note <tt>d.run(s)</tt> is just a shortcut of the following code.
|
alpar@100
|
601 |
///\code
|
alpar@100
|
602 |
/// d.init();
|
kpeter@244
|
603 |
/// d.addSource(s);
|
kpeter@244
|
604 |
/// d.start();
|
kpeter@244
|
605 |
///\endcode
|
kpeter@244
|
606 |
void run(Node s) {
|
kpeter@244
|
607 |
init();
|
kpeter@244
|
608 |
addSource(s);
|
kpeter@244
|
609 |
start();
|
kpeter@244
|
610 |
}
|
kpeter@244
|
611 |
|
kpeter@244
|
612 |
///Finds the %DFS path between \c s and \c t.
|
kpeter@244
|
613 |
|
kpeter@244
|
614 |
///This method runs the %DFS algorithm from node \c s
|
kpeter@286
|
615 |
///in order to compute the DFS path to node \c t
|
kpeter@286
|
616 |
///(it stops searching when \c t is processed)
|
kpeter@244
|
617 |
///
|
kpeter@286
|
618 |
///\return \c true if \c t is reachable form \c s.
|
kpeter@244
|
619 |
///
|
kpeter@244
|
620 |
///\note Apart from the return value, <tt>d.run(s,t)</tt> is
|
kpeter@244
|
621 |
///just a shortcut of the following code.
|
kpeter@244
|
622 |
///\code
|
kpeter@244
|
623 |
/// d.init();
|
kpeter@244
|
624 |
/// d.addSource(s);
|
kpeter@244
|
625 |
/// d.start(t);
|
kpeter@244
|
626 |
///\endcode
|
kpeter@286
|
627 |
bool run(Node s,Node t) {
|
kpeter@244
|
628 |
init();
|
kpeter@244
|
629 |
addSource(s);
|
kpeter@244
|
630 |
start(t);
|
kpeter@286
|
631 |
return reached(t);
|
kpeter@244
|
632 |
}
|
kpeter@244
|
633 |
|
kpeter@244
|
634 |
///Runs the algorithm to visit all nodes in the digraph.
|
kpeter@244
|
635 |
|
kpeter@244
|
636 |
///This method runs the %DFS algorithm in order to compute the
|
kpeter@244
|
637 |
///%DFS path to each node.
|
kpeter@244
|
638 |
///
|
kpeter@244
|
639 |
///The algorithm computes
|
kpeter@244
|
640 |
///- the %DFS tree,
|
kpeter@244
|
641 |
///- the distance of each node from the root in the %DFS tree.
|
kpeter@244
|
642 |
///
|
kpeter@244
|
643 |
///\note <tt>d.run()</tt> is just a shortcut of the following code.
|
kpeter@244
|
644 |
///\code
|
kpeter@244
|
645 |
/// d.init();
|
kpeter@244
|
646 |
/// for (NodeIt n(digraph); n != INVALID; ++n) {
|
kpeter@244
|
647 |
/// if (!d.reached(n)) {
|
kpeter@244
|
648 |
/// d.addSource(n);
|
alpar@100
|
649 |
/// d.start();
|
alpar@100
|
650 |
/// }
|
alpar@100
|
651 |
/// }
|
alpar@100
|
652 |
///\endcode
|
alpar@100
|
653 |
void run() {
|
alpar@100
|
654 |
init();
|
alpar@100
|
655 |
for (NodeIt it(*G); it != INVALID; ++it) {
|
alpar@100
|
656 |
if (!reached(it)) {
|
alpar@100
|
657 |
addSource(it);
|
alpar@100
|
658 |
start();
|
alpar@100
|
659 |
}
|
alpar@100
|
660 |
}
|
alpar@100
|
661 |
}
|
alpar@100
|
662 |
|
alpar@100
|
663 |
///@}
|
alpar@100
|
664 |
|
alpar@100
|
665 |
///\name Query Functions
|
alpar@100
|
666 |
///The result of the %DFS algorithm can be obtained using these
|
alpar@100
|
667 |
///functions.\n
|
kpeter@244
|
668 |
///Either \ref lemon::Dfs::run() "run()" or \ref lemon::Dfs::start()
|
kpeter@244
|
669 |
///"start()" must be called before using them.
|
alpar@209
|
670 |
|
alpar@100
|
671 |
///@{
|
alpar@100
|
672 |
|
kpeter@244
|
673 |
///The DFS path to a node.
|
alpar@100
|
674 |
|
kpeter@244
|
675 |
///Returns the DFS path to a node.
|
kpeter@244
|
676 |
///
|
kpeter@244
|
677 |
///\warning \c t should be reachable from the root.
|
kpeter@244
|
678 |
///
|
kpeter@244
|
679 |
///\pre Either \ref run() or \ref start() must be called before
|
kpeter@244
|
680 |
///using this function.
|
kpeter@244
|
681 |
Path path(Node t) const { return Path(*G, *_pred, t); }
|
alpar@209
|
682 |
|
kpeter@244
|
683 |
///The distance of a node from the root.
|
alpar@100
|
684 |
|
kpeter@244
|
685 |
///Returns the distance of a node from the root.
|
kpeter@244
|
686 |
///
|
kpeter@244
|
687 |
///\warning If node \c v is not reachable from the root, then
|
kpeter@244
|
688 |
///the return value of this function is undefined.
|
kpeter@244
|
689 |
///
|
kpeter@244
|
690 |
///\pre Either \ref run() or \ref start() must be called before
|
kpeter@244
|
691 |
///using this function.
|
alpar@100
|
692 |
int dist(Node v) const { return (*_dist)[v]; }
|
alpar@100
|
693 |
|
kpeter@244
|
694 |
///Returns the 'previous arc' of the %DFS tree for a node.
|
alpar@100
|
695 |
|
kpeter@244
|
696 |
///This function returns the 'previous arc' of the %DFS tree for the
|
kpeter@244
|
697 |
///node \c v, i.e. it returns the last arc of a %DFS path from the
|
kpeter@244
|
698 |
///root to \c v. It is \c INVALID
|
kpeter@244
|
699 |
///if \c v is not reachable from the root(s) or if \c v is a root.
|
kpeter@244
|
700 |
///
|
kpeter@244
|
701 |
///The %DFS tree used here is equal to the %DFS tree used in
|
alpar@100
|
702 |
///\ref predNode().
|
kpeter@244
|
703 |
///
|
alpar@100
|
704 |
///\pre Either \ref run() or \ref start() must be called before using
|
alpar@100
|
705 |
///this function.
|
alpar@100
|
706 |
Arc predArc(Node v) const { return (*_pred)[v];}
|
alpar@100
|
707 |
|
alpar@100
|
708 |
///Returns the 'previous node' of the %DFS tree.
|
alpar@100
|
709 |
|
kpeter@244
|
710 |
///This function returns the 'previous node' of the %DFS
|
kpeter@244
|
711 |
///tree for the node \c v, i.e. it returns the last but one node
|
kpeter@244
|
712 |
///from a %DFS path from the root to \c v. It is \c INVALID
|
kpeter@244
|
713 |
///if \c v is not reachable from the root(s) or if \c v is a root.
|
kpeter@244
|
714 |
///
|
kpeter@244
|
715 |
///The %DFS tree used here is equal to the %DFS tree used in
|
kpeter@244
|
716 |
///\ref predArc().
|
kpeter@244
|
717 |
///
|
alpar@100
|
718 |
///\pre Either \ref run() or \ref start() must be called before
|
alpar@100
|
719 |
///using this function.
|
alpar@100
|
720 |
Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
|
alpar@209
|
721 |
G->source((*_pred)[v]); }
|
alpar@209
|
722 |
|
kpeter@244
|
723 |
///\brief Returns a const reference to the node map that stores the
|
kpeter@244
|
724 |
///distances of the nodes.
|
kpeter@244
|
725 |
///
|
kpeter@244
|
726 |
///Returns a const reference to the node map that stores the
|
kpeter@244
|
727 |
///distances of the nodes calculated by the algorithm.
|
kpeter@244
|
728 |
///
|
kpeter@244
|
729 |
///\pre Either \ref run() or \ref init()
|
kpeter@244
|
730 |
///must be called before using this function.
|
alpar@100
|
731 |
const DistMap &distMap() const { return *_dist;}
|
alpar@209
|
732 |
|
kpeter@244
|
733 |
///\brief Returns a const reference to the node map that stores the
|
kpeter@244
|
734 |
///predecessor arcs.
|
kpeter@244
|
735 |
///
|
kpeter@244
|
736 |
///Returns a const reference to the node map that stores the predecessor
|
kpeter@244
|
737 |
///arcs, which form the DFS tree.
|
kpeter@244
|
738 |
///
|
alpar@100
|
739 |
///\pre Either \ref run() or \ref init()
|
alpar@100
|
740 |
///must be called before using this function.
|
alpar@100
|
741 |
const PredMap &predMap() const { return *_pred;}
|
alpar@209
|
742 |
|
kpeter@244
|
743 |
///Checks if a node is reachable from the root(s).
|
alpar@100
|
744 |
|
alpar@100
|
745 |
///Returns \c true if \c v is reachable from the root(s).
|
alpar@100
|
746 |
///\pre Either \ref run() or \ref start()
|
alpar@100
|
747 |
///must be called before using this function.
|
kpeter@244
|
748 |
bool reached(Node v) const { return (*_reached)[v]; }
|
alpar@209
|
749 |
|
alpar@100
|
750 |
///@}
|
alpar@100
|
751 |
};
|
alpar@100
|
752 |
|
kpeter@244
|
753 |
///Default traits class of dfs() function.
|
alpar@100
|
754 |
|
kpeter@244
|
755 |
///Default traits class of dfs() function.
|
kpeter@157
|
756 |
///\tparam GR Digraph type.
|
alpar@100
|
757 |
template<class GR>
|
alpar@100
|
758 |
struct DfsWizardDefaultTraits
|
alpar@100
|
759 |
{
|
kpeter@244
|
760 |
///The type of the digraph the algorithm runs on.
|
alpar@100
|
761 |
typedef GR Digraph;
|
kpeter@244
|
762 |
|
kpeter@244
|
763 |
///\brief The type of the map that stores the predecessor
|
alpar@100
|
764 |
///arcs of the %DFS paths.
|
alpar@209
|
765 |
///
|
kpeter@244
|
766 |
///The type of the map that stores the predecessor
|
alpar@100
|
767 |
///arcs of the %DFS paths.
|
alpar@100
|
768 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept.
|
kpeter@278
|
769 |
typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
|
kpeter@305
|
770 |
///Instantiates a PredMap.
|
alpar@209
|
771 |
|
kpeter@305
|
772 |
///This function instantiates a PredMap.
|
kpeter@244
|
773 |
///\param g is the digraph, to which we would like to define the
|
kpeter@305
|
774 |
///PredMap.
|
kpeter@244
|
775 |
static PredMap *createPredMap(const Digraph &g)
|
alpar@100
|
776 |
{
|
kpeter@278
|
777 |
return new PredMap(g);
|
alpar@100
|
778 |
}
|
alpar@100
|
779 |
|
alpar@100
|
780 |
///The type of the map that indicates which nodes are processed.
|
alpar@209
|
781 |
|
alpar@100
|
782 |
///The type of the map that indicates which nodes are processed.
|
alpar@100
|
783 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept.
|
kpeter@278
|
784 |
///By default it is a NullMap.
|
alpar@100
|
785 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
|
kpeter@305
|
786 |
///Instantiates a ProcessedMap.
|
alpar@209
|
787 |
|
kpeter@305
|
788 |
///This function instantiates a ProcessedMap.
|
alpar@100
|
789 |
///\param g is the digraph, to which
|
kpeter@305
|
790 |
///we would like to define the ProcessedMap.
|
alpar@100
|
791 |
#ifdef DOXYGEN
|
kpeter@244
|
792 |
static ProcessedMap *createProcessedMap(const Digraph &g)
|
alpar@100
|
793 |
#else
|
kpeter@244
|
794 |
static ProcessedMap *createProcessedMap(const Digraph &)
|
alpar@100
|
795 |
#endif
|
alpar@100
|
796 |
{
|
alpar@100
|
797 |
return new ProcessedMap();
|
alpar@100
|
798 |
}
|
kpeter@244
|
799 |
|
alpar@100
|
800 |
///The type of the map that indicates which nodes are reached.
|
alpar@209
|
801 |
|
alpar@100
|
802 |
///The type of the map that indicates which nodes are reached.
|
kpeter@244
|
803 |
///It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
|
alpar@100
|
804 |
typedef typename Digraph::template NodeMap<bool> ReachedMap;
|
kpeter@305
|
805 |
///Instantiates a ReachedMap.
|
alpar@209
|
806 |
|
kpeter@305
|
807 |
///This function instantiates a ReachedMap.
|
kpeter@244
|
808 |
///\param g is the digraph, to which
|
kpeter@305
|
809 |
///we would like to define the ReachedMap.
|
kpeter@244
|
810 |
static ReachedMap *createReachedMap(const Digraph &g)
|
alpar@100
|
811 |
{
|
kpeter@244
|
812 |
return new ReachedMap(g);
|
alpar@100
|
813 |
}
|
alpar@209
|
814 |
|
kpeter@244
|
815 |
///The type of the map that stores the distances of the nodes.
|
kpeter@244
|
816 |
|
kpeter@244
|
817 |
///The type of the map that stores the distances of the nodes.
|
alpar@100
|
818 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept.
|
kpeter@278
|
819 |
typedef typename Digraph::template NodeMap<int> DistMap;
|
kpeter@305
|
820 |
///Instantiates a DistMap.
|
alpar@209
|
821 |
|
kpeter@305
|
822 |
///This function instantiates a DistMap.
|
alpar@210
|
823 |
///\param g is the digraph, to which we would like to define
|
kpeter@305
|
824 |
///the DistMap
|
kpeter@244
|
825 |
static DistMap *createDistMap(const Digraph &g)
|
alpar@100
|
826 |
{
|
kpeter@278
|
827 |
return new DistMap(g);
|
alpar@100
|
828 |
}
|
kpeter@278
|
829 |
|
kpeter@278
|
830 |
///The type of the DFS paths.
|
kpeter@278
|
831 |
|
kpeter@278
|
832 |
///The type of the DFS paths.
|
kpeter@278
|
833 |
///It must meet the \ref concepts::Path "Path" concept.
|
kpeter@278
|
834 |
typedef lemon::Path<Digraph> Path;
|
alpar@100
|
835 |
};
|
alpar@209
|
836 |
|
kpeter@317
|
837 |
/// Default traits class used by DfsWizard
|
alpar@100
|
838 |
|
alpar@100
|
839 |
/// To make it easier to use Dfs algorithm
|
kpeter@244
|
840 |
/// we have created a wizard class.
|
alpar@100
|
841 |
/// This \ref DfsWizard class needs default traits,
|
kpeter@244
|
842 |
/// as well as the \ref Dfs class.
|
alpar@100
|
843 |
/// The \ref DfsWizardBase is a class to be the default traits of the
|
alpar@100
|
844 |
/// \ref DfsWizard class.
|
alpar@100
|
845 |
template<class GR>
|
alpar@100
|
846 |
class DfsWizardBase : public DfsWizardDefaultTraits<GR>
|
alpar@100
|
847 |
{
|
alpar@100
|
848 |
|
alpar@100
|
849 |
typedef DfsWizardDefaultTraits<GR> Base;
|
alpar@100
|
850 |
protected:
|
kpeter@244
|
851 |
//The type of the nodes in the digraph.
|
alpar@100
|
852 |
typedef typename Base::Digraph::Node Node;
|
alpar@100
|
853 |
|
kpeter@244
|
854 |
//Pointer to the digraph the algorithm runs on.
|
alpar@100
|
855 |
void *_g;
|
kpeter@244
|
856 |
//Pointer to the map of reached nodes.
|
alpar@100
|
857 |
void *_reached;
|
kpeter@244
|
858 |
//Pointer to the map of processed nodes.
|
alpar@100
|
859 |
void *_processed;
|
kpeter@244
|
860 |
//Pointer to the map of predecessors arcs.
|
alpar@100
|
861 |
void *_pred;
|
kpeter@244
|
862 |
//Pointer to the map of distances.
|
alpar@100
|
863 |
void *_dist;
|
kpeter@278
|
864 |
//Pointer to the DFS path to the target node.
|
kpeter@278
|
865 |
void *_path;
|
kpeter@278
|
866 |
//Pointer to the distance of the target node.
|
kpeter@278
|
867 |
int *_di;
|
alpar@209
|
868 |
|
alpar@100
|
869 |
public:
|
alpar@100
|
870 |
/// Constructor.
|
alpar@209
|
871 |
|
alpar@100
|
872 |
/// This constructor does not require parameters, therefore it initiates
|
kpeter@278
|
873 |
/// all of the attributes to \c 0.
|
alpar@100
|
874 |
DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0),
|
kpeter@278
|
875 |
_dist(0), _path(0), _di(0) {}
|
alpar@100
|
876 |
|
alpar@100
|
877 |
/// Constructor.
|
alpar@209
|
878 |
|
kpeter@278
|
879 |
/// This constructor requires one parameter,
|
kpeter@278
|
880 |
/// others are initiated to \c 0.
|
kpeter@244
|
881 |
/// \param g The digraph the algorithm runs on.
|
kpeter@278
|
882 |
DfsWizardBase(const GR &g) :
|
alpar@209
|
883 |
_g(reinterpret_cast<void*>(const_cast<GR*>(&g))),
|
kpeter@278
|
884 |
_reached(0), _processed(0), _pred(0), _dist(0), _path(0), _di(0) {}
|
alpar@100
|
885 |
|
alpar@100
|
886 |
};
|
alpar@209
|
887 |
|
kpeter@278
|
888 |
/// Auxiliary class for the function-type interface of DFS algorithm.
|
alpar@100
|
889 |
|
kpeter@278
|
890 |
/// This auxiliary class is created to implement the
|
kpeter@278
|
891 |
/// \ref dfs() "function-type interface" of \ref Dfs algorithm.
|
kpeter@278
|
892 |
/// It does not have own \ref run() method, it uses the functions
|
kpeter@278
|
893 |
/// and features of the plain \ref Dfs.
|
alpar@100
|
894 |
///
|
kpeter@278
|
895 |
/// This class should only be used through the \ref dfs() function,
|
kpeter@278
|
896 |
/// which makes it easier to use the algorithm.
|
alpar@100
|
897 |
template<class TR>
|
alpar@100
|
898 |
class DfsWizard : public TR
|
alpar@100
|
899 |
{
|
alpar@100
|
900 |
typedef TR Base;
|
alpar@100
|
901 |
|
kpeter@244
|
902 |
///The type of the digraph the algorithm runs on.
|
alpar@100
|
903 |
typedef typename TR::Digraph Digraph;
|
kpeter@244
|
904 |
|
alpar@100
|
905 |
typedef typename Digraph::Node Node;
|
alpar@100
|
906 |
typedef typename Digraph::NodeIt NodeIt;
|
alpar@100
|
907 |
typedef typename Digraph::Arc Arc;
|
alpar@100
|
908 |
typedef typename Digraph::OutArcIt OutArcIt;
|
alpar@209
|
909 |
|
kpeter@244
|
910 |
///\brief The type of the map that stores the predecessor
|
kpeter@278
|
911 |
///arcs of the DFS paths.
|
kpeter@244
|
912 |
typedef typename TR::PredMap PredMap;
|
kpeter@244
|
913 |
///\brief The type of the map that stores the distances of the nodes.
|
kpeter@244
|
914 |
typedef typename TR::DistMap DistMap;
|
kpeter@244
|
915 |
///\brief The type of the map that indicates which nodes are reached.
|
alpar@100
|
916 |
typedef typename TR::ReachedMap ReachedMap;
|
kpeter@244
|
917 |
///\brief The type of the map that indicates which nodes are processed.
|
alpar@100
|
918 |
typedef typename TR::ProcessedMap ProcessedMap;
|
kpeter@278
|
919 |
///The type of the DFS paths
|
kpeter@278
|
920 |
typedef typename TR::Path Path;
|
alpar@100
|
921 |
|
alpar@100
|
922 |
public:
|
kpeter@244
|
923 |
|
alpar@100
|
924 |
/// Constructor.
|
alpar@100
|
925 |
DfsWizard() : TR() {}
|
alpar@100
|
926 |
|
alpar@100
|
927 |
/// Constructor that requires parameters.
|
alpar@100
|
928 |
|
alpar@100
|
929 |
/// Constructor that requires parameters.
|
alpar@100
|
930 |
/// These parameters will be the default values for the traits class.
|
kpeter@278
|
931 |
/// \param g The digraph the algorithm runs on.
|
kpeter@278
|
932 |
DfsWizard(const Digraph &g) :
|
kpeter@278
|
933 |
TR(g) {}
|
alpar@100
|
934 |
|
alpar@100
|
935 |
///Copy constructor
|
alpar@100
|
936 |
DfsWizard(const TR &b) : TR(b) {}
|
alpar@100
|
937 |
|
alpar@100
|
938 |
~DfsWizard() {}
|
alpar@100
|
939 |
|
kpeter@278
|
940 |
///Runs DFS algorithm from the given source node.
|
alpar@209
|
941 |
|
kpeter@278
|
942 |
///This method runs DFS algorithm from node \c s
|
kpeter@278
|
943 |
///in order to compute the DFS path to each node.
|
kpeter@278
|
944 |
void run(Node s)
|
kpeter@278
|
945 |
{
|
kpeter@278
|
946 |
Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
|
kpeter@278
|
947 |
if (Base::_pred)
|
kpeter@278
|
948 |
alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
|
kpeter@278
|
949 |
if (Base::_dist)
|
kpeter@278
|
950 |
alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
|
kpeter@278
|
951 |
if (Base::_reached)
|
kpeter@278
|
952 |
alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
|
kpeter@278
|
953 |
if (Base::_processed)
|
kpeter@278
|
954 |
alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
|
kpeter@278
|
955 |
if (s!=INVALID)
|
kpeter@278
|
956 |
alg.run(s);
|
kpeter@278
|
957 |
else
|
kpeter@278
|
958 |
alg.run();
|
kpeter@278
|
959 |
}
|
kpeter@278
|
960 |
|
kpeter@278
|
961 |
///Finds the DFS path between \c s and \c t.
|
kpeter@278
|
962 |
|
kpeter@278
|
963 |
///This method runs DFS algorithm from node \c s
|
kpeter@278
|
964 |
///in order to compute the DFS path to node \c t
|
kpeter@278
|
965 |
///(it stops searching when \c t is processed).
|
kpeter@278
|
966 |
///
|
kpeter@278
|
967 |
///\return \c true if \c t is reachable form \c s.
|
kpeter@278
|
968 |
bool run(Node s, Node t)
|
kpeter@278
|
969 |
{
|
kpeter@278
|
970 |
Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
|
kpeter@278
|
971 |
if (Base::_pred)
|
kpeter@278
|
972 |
alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
|
kpeter@278
|
973 |
if (Base::_dist)
|
kpeter@278
|
974 |
alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
|
kpeter@278
|
975 |
if (Base::_reached)
|
kpeter@278
|
976 |
alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
|
kpeter@278
|
977 |
if (Base::_processed)
|
kpeter@278
|
978 |
alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
|
kpeter@278
|
979 |
alg.run(s,t);
|
kpeter@278
|
980 |
if (Base::_path)
|
kpeter@278
|
981 |
*reinterpret_cast<Path*>(Base::_path) = alg.path(t);
|
kpeter@278
|
982 |
if (Base::_di)
|
kpeter@278
|
983 |
*Base::_di = alg.dist(t);
|
kpeter@278
|
984 |
return alg.reached(t);
|
kpeter@278
|
985 |
}
|
kpeter@278
|
986 |
|
kpeter@278
|
987 |
///Runs DFS algorithm to visit all nodes in the digraph.
|
kpeter@278
|
988 |
|
kpeter@278
|
989 |
///This method runs DFS algorithm in order to compute
|
kpeter@278
|
990 |
///the DFS path to each node.
|
alpar@100
|
991 |
void run()
|
alpar@100
|
992 |
{
|
kpeter@278
|
993 |
run(INVALID);
|
kpeter@244
|
994 |
}
|
kpeter@244
|
995 |
|
alpar@100
|
996 |
template<class T>
|
kpeter@257
|
997 |
struct SetPredMapBase : public Base {
|
alpar@100
|
998 |
typedef T PredMap;
|
alpar@100
|
999 |
static PredMap *createPredMap(const Digraph &) { return 0; };
|
kpeter@257
|
1000 |
SetPredMapBase(const TR &b) : TR(b) {}
|
alpar@100
|
1001 |
};
|
kpeter@278
|
1002 |
///\brief \ref named-func-param "Named parameter"
|
kpeter@305
|
1003 |
///for setting PredMap object.
|
alpar@100
|
1004 |
///
|
kpeter@278
|
1005 |
///\ref named-func-param "Named parameter"
|
kpeter@305
|
1006 |
///for setting PredMap object.
|
alpar@100
|
1007 |
template<class T>
|
kpeter@257
|
1008 |
DfsWizard<SetPredMapBase<T> > predMap(const T &t)
|
alpar@100
|
1009 |
{
|
alpar@100
|
1010 |
Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
|
kpeter@257
|
1011 |
return DfsWizard<SetPredMapBase<T> >(*this);
|
alpar@100
|
1012 |
}
|
alpar@209
|
1013 |
|
alpar@100
|
1014 |
template<class T>
|
kpeter@257
|
1015 |
struct SetReachedMapBase : public Base {
|
alpar@100
|
1016 |
typedef T ReachedMap;
|
alpar@100
|
1017 |
static ReachedMap *createReachedMap(const Digraph &) { return 0; };
|
kpeter@257
|
1018 |
SetReachedMapBase(const TR &b) : TR(b) {}
|
alpar@100
|
1019 |
};
|
kpeter@278
|
1020 |
///\brief \ref named-func-param "Named parameter"
|
kpeter@305
|
1021 |
///for setting ReachedMap object.
|
alpar@100
|
1022 |
///
|
kpeter@278
|
1023 |
/// \ref named-func-param "Named parameter"
|
kpeter@305
|
1024 |
///for setting ReachedMap object.
|
alpar@100
|
1025 |
template<class T>
|
kpeter@257
|
1026 |
DfsWizard<SetReachedMapBase<T> > reachedMap(const T &t)
|
alpar@100
|
1027 |
{
|
deba@158
|
1028 |
Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t));
|
kpeter@257
|
1029 |
return DfsWizard<SetReachedMapBase<T> >(*this);
|
alpar@100
|
1030 |
}
|
alpar@209
|
1031 |
|
alpar@100
|
1032 |
template<class T>
|
kpeter@278
|
1033 |
struct SetDistMapBase : public Base {
|
kpeter@278
|
1034 |
typedef T DistMap;
|
kpeter@278
|
1035 |
static DistMap *createDistMap(const Digraph &) { return 0; };
|
kpeter@278
|
1036 |
SetDistMapBase(const TR &b) : TR(b) {}
|
kpeter@278
|
1037 |
};
|
kpeter@278
|
1038 |
///\brief \ref named-func-param "Named parameter"
|
kpeter@305
|
1039 |
///for setting DistMap object.
|
kpeter@278
|
1040 |
///
|
kpeter@278
|
1041 |
/// \ref named-func-param "Named parameter"
|
kpeter@305
|
1042 |
///for setting DistMap object.
|
kpeter@278
|
1043 |
template<class T>
|
kpeter@278
|
1044 |
DfsWizard<SetDistMapBase<T> > distMap(const T &t)
|
kpeter@278
|
1045 |
{
|
kpeter@278
|
1046 |
Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
|
kpeter@278
|
1047 |
return DfsWizard<SetDistMapBase<T> >(*this);
|
kpeter@278
|
1048 |
}
|
kpeter@278
|
1049 |
|
kpeter@278
|
1050 |
template<class T>
|
kpeter@257
|
1051 |
struct SetProcessedMapBase : public Base {
|
alpar@100
|
1052 |
typedef T ProcessedMap;
|
alpar@100
|
1053 |
static ProcessedMap *createProcessedMap(const Digraph &) { return 0; };
|
kpeter@257
|
1054 |
SetProcessedMapBase(const TR &b) : TR(b) {}
|
alpar@100
|
1055 |
};
|
kpeter@278
|
1056 |
///\brief \ref named-func-param "Named parameter"
|
kpeter@305
|
1057 |
///for setting ProcessedMap object.
|
alpar@100
|
1058 |
///
|
kpeter@278
|
1059 |
/// \ref named-func-param "Named parameter"
|
kpeter@305
|
1060 |
///for setting ProcessedMap object.
|
alpar@100
|
1061 |
template<class T>
|
kpeter@257
|
1062 |
DfsWizard<SetProcessedMapBase<T> > processedMap(const T &t)
|
alpar@100
|
1063 |
{
|
deba@158
|
1064 |
Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t));
|
kpeter@257
|
1065 |
return DfsWizard<SetProcessedMapBase<T> >(*this);
|
alpar@100
|
1066 |
}
|
alpar@209
|
1067 |
|
alpar@100
|
1068 |
template<class T>
|
kpeter@278
|
1069 |
struct SetPathBase : public Base {
|
kpeter@278
|
1070 |
typedef T Path;
|
kpeter@278
|
1071 |
SetPathBase(const TR &b) : TR(b) {}
|
alpar@100
|
1072 |
};
|
kpeter@278
|
1073 |
///\brief \ref named-func-param "Named parameter"
|
kpeter@278
|
1074 |
///for getting the DFS path to the target node.
|
alpar@100
|
1075 |
///
|
kpeter@278
|
1076 |
///\ref named-func-param "Named parameter"
|
kpeter@278
|
1077 |
///for getting the DFS path to the target node.
|
alpar@100
|
1078 |
template<class T>
|
kpeter@278
|
1079 |
DfsWizard<SetPathBase<T> > path(const T &t)
|
alpar@100
|
1080 |
{
|
kpeter@278
|
1081 |
Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t));
|
kpeter@278
|
1082 |
return DfsWizard<SetPathBase<T> >(*this);
|
kpeter@278
|
1083 |
}
|
kpeter@278
|
1084 |
|
kpeter@278
|
1085 |
///\brief \ref named-func-param "Named parameter"
|
kpeter@278
|
1086 |
///for getting the distance of the target node.
|
kpeter@278
|
1087 |
///
|
kpeter@278
|
1088 |
///\ref named-func-param "Named parameter"
|
kpeter@278
|
1089 |
///for getting the distance of the target node.
|
kpeter@278
|
1090 |
DfsWizard dist(const int &d)
|
kpeter@278
|
1091 |
{
|
kpeter@278
|
1092 |
Base::_di=const_cast<int*>(&d);
|
kpeter@278
|
1093 |
return *this;
|
alpar@100
|
1094 |
}
|
alpar@209
|
1095 |
|
alpar@100
|
1096 |
};
|
alpar@209
|
1097 |
|
kpeter@278
|
1098 |
///Function-type interface for DFS algorithm.
|
alpar@100
|
1099 |
|
alpar@100
|
1100 |
///\ingroup search
|
kpeter@278
|
1101 |
///Function-type interface for DFS algorithm.
|
alpar@100
|
1102 |
///
|
kpeter@278
|
1103 |
///This function also has several \ref named-func-param "named parameters",
|
alpar@100
|
1104 |
///they are declared as the members of class \ref DfsWizard.
|
kpeter@278
|
1105 |
///The following examples show how to use these parameters.
|
alpar@100
|
1106 |
///\code
|
kpeter@278
|
1107 |
/// // Compute the DFS tree
|
kpeter@278
|
1108 |
/// dfs(g).predMap(preds).distMap(dists).run(s);
|
kpeter@278
|
1109 |
///
|
kpeter@278
|
1110 |
/// // Compute the DFS path from s to t
|
kpeter@278
|
1111 |
/// bool reached = dfs(g).path(p).dist(d).run(s,t);
|
alpar@100
|
1112 |
///\endcode
|
kpeter@278
|
1113 |
|
alpar@100
|
1114 |
///\warning Don't forget to put the \ref DfsWizard::run() "run()"
|
alpar@100
|
1115 |
///to the end of the parameter list.
|
alpar@100
|
1116 |
///\sa DfsWizard
|
alpar@100
|
1117 |
///\sa Dfs
|
alpar@100
|
1118 |
template<class GR>
|
alpar@100
|
1119 |
DfsWizard<DfsWizardBase<GR> >
|
kpeter@278
|
1120 |
dfs(const GR &digraph)
|
alpar@100
|
1121 |
{
|
kpeter@278
|
1122 |
return DfsWizard<DfsWizardBase<GR> >(digraph);
|
alpar@100
|
1123 |
}
|
alpar@100
|
1124 |
|
alpar@100
|
1125 |
#ifdef DOXYGEN
|
kpeter@244
|
1126 |
/// \brief Visitor class for DFS.
|
alpar@209
|
1127 |
///
|
kpeter@244
|
1128 |
/// This class defines the interface of the DfsVisit events, and
|
kpeter@244
|
1129 |
/// it could be the base of a real visitor class.
|
alpar@100
|
1130 |
template <typename _Digraph>
|
alpar@100
|
1131 |
struct DfsVisitor {
|
alpar@100
|
1132 |
typedef _Digraph Digraph;
|
alpar@100
|
1133 |
typedef typename Digraph::Arc Arc;
|
alpar@100
|
1134 |
typedef typename Digraph::Node Node;
|
kpeter@244
|
1135 |
/// \brief Called for the source node of the DFS.
|
alpar@209
|
1136 |
///
|
kpeter@244
|
1137 |
/// This function is called for the source node of the DFS.
|
kpeter@244
|
1138 |
void start(const Node& node) {}
|
kpeter@244
|
1139 |
/// \brief Called when the source node is leaved.
|
kpeter@244
|
1140 |
///
|
kpeter@244
|
1141 |
/// This function is called when the source node is leaved.
|
kpeter@244
|
1142 |
void stop(const Node& node) {}
|
kpeter@244
|
1143 |
/// \brief Called when a node is reached first time.
|
kpeter@244
|
1144 |
///
|
kpeter@244
|
1145 |
/// This function is called when a node is reached first time.
|
kpeter@244
|
1146 |
void reach(const Node& node) {}
|
kpeter@244
|
1147 |
/// \brief Called when an arc reaches a new node.
|
kpeter@244
|
1148 |
///
|
kpeter@244
|
1149 |
/// This function is called when the DFS finds an arc whose target node
|
kpeter@244
|
1150 |
/// is not reached yet.
|
alpar@100
|
1151 |
void discover(const Arc& arc) {}
|
kpeter@244
|
1152 |
/// \brief Called when an arc is examined but its target node is
|
alpar@100
|
1153 |
/// already discovered.
|
alpar@209
|
1154 |
///
|
kpeter@244
|
1155 |
/// This function is called when an arc is examined but its target node is
|
alpar@100
|
1156 |
/// already discovered.
|
alpar@100
|
1157 |
void examine(const Arc& arc) {}
|
kpeter@244
|
1158 |
/// \brief Called when the DFS steps back from a node.
|
alpar@209
|
1159 |
///
|
kpeter@244
|
1160 |
/// This function is called when the DFS steps back from a node.
|
kpeter@244
|
1161 |
void leave(const Node& node) {}
|
kpeter@244
|
1162 |
/// \brief Called when the DFS steps back on an arc.
|
alpar@209
|
1163 |
///
|
kpeter@244
|
1164 |
/// This function is called when the DFS steps back on an arc.
|
kpeter@244
|
1165 |
void backtrack(const Arc& arc) {}
|
alpar@100
|
1166 |
};
|
alpar@100
|
1167 |
#else
|
alpar@100
|
1168 |
template <typename _Digraph>
|
alpar@100
|
1169 |
struct DfsVisitor {
|
alpar@100
|
1170 |
typedef _Digraph Digraph;
|
alpar@100
|
1171 |
typedef typename Digraph::Arc Arc;
|
alpar@100
|
1172 |
typedef typename Digraph::Node Node;
|
alpar@100
|
1173 |
void start(const Node&) {}
|
alpar@100
|
1174 |
void stop(const Node&) {}
|
kpeter@244
|
1175 |
void reach(const Node&) {}
|
kpeter@244
|
1176 |
void discover(const Arc&) {}
|
kpeter@244
|
1177 |
void examine(const Arc&) {}
|
kpeter@244
|
1178 |
void leave(const Node&) {}
|
kpeter@244
|
1179 |
void backtrack(const Arc&) {}
|
alpar@100
|
1180 |
|
alpar@100
|
1181 |
template <typename _Visitor>
|
alpar@100
|
1182 |
struct Constraints {
|
alpar@100
|
1183 |
void constraints() {
|
alpar@209
|
1184 |
Arc arc;
|
alpar@209
|
1185 |
Node node;
|
alpar@209
|
1186 |
visitor.start(node);
|
alpar@209
|
1187 |
visitor.stop(arc);
|
kpeter@244
|
1188 |
visitor.reach(node);
|
kpeter@244
|
1189 |
visitor.discover(arc);
|
kpeter@244
|
1190 |
visitor.examine(arc);
|
kpeter@244
|
1191 |
visitor.leave(node);
|
kpeter@244
|
1192 |
visitor.backtrack(arc);
|
alpar@100
|
1193 |
}
|
alpar@100
|
1194 |
_Visitor& visitor;
|
alpar@100
|
1195 |
};
|
alpar@100
|
1196 |
};
|
alpar@100
|
1197 |
#endif
|
alpar@100
|
1198 |
|
alpar@100
|
1199 |
/// \brief Default traits class of DfsVisit class.
|
alpar@100
|
1200 |
///
|
alpar@100
|
1201 |
/// Default traits class of DfsVisit class.
|
kpeter@244
|
1202 |
/// \tparam _Digraph The type of the digraph the algorithm runs on.
|
alpar@100
|
1203 |
template<class _Digraph>
|
alpar@100
|
1204 |
struct DfsVisitDefaultTraits {
|
alpar@100
|
1205 |
|
kpeter@244
|
1206 |
/// \brief The type of the digraph the algorithm runs on.
|
alpar@100
|
1207 |
typedef _Digraph Digraph;
|
alpar@100
|
1208 |
|
alpar@100
|
1209 |
/// \brief The type of the map that indicates which nodes are reached.
|
alpar@209
|
1210 |
///
|
alpar@100
|
1211 |
/// The type of the map that indicates which nodes are reached.
|
kpeter@244
|
1212 |
/// It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
|
alpar@100
|
1213 |
typedef typename Digraph::template NodeMap<bool> ReachedMap;
|
alpar@100
|
1214 |
|
kpeter@305
|
1215 |
/// \brief Instantiates a ReachedMap.
|
alpar@100
|
1216 |
///
|
kpeter@305
|
1217 |
/// This function instantiates a ReachedMap.
|
alpar@100
|
1218 |
/// \param digraph is the digraph, to which
|
kpeter@305
|
1219 |
/// we would like to define the ReachedMap.
|
alpar@100
|
1220 |
static ReachedMap *createReachedMap(const Digraph &digraph) {
|
alpar@100
|
1221 |
return new ReachedMap(digraph);
|
alpar@100
|
1222 |
}
|
alpar@100
|
1223 |
|
alpar@100
|
1224 |
};
|
alpar@209
|
1225 |
|
alpar@100
|
1226 |
/// \ingroup search
|
kpeter@244
|
1227 |
///
|
kpeter@244
|
1228 |
/// \brief %DFS algorithm class with visitor interface.
|
kpeter@244
|
1229 |
///
|
alpar@100
|
1230 |
/// This class provides an efficient implementation of the %DFS algorithm
|
alpar@100
|
1231 |
/// with visitor interface.
|
alpar@100
|
1232 |
///
|
alpar@100
|
1233 |
/// The %DfsVisit class provides an alternative interface to the Dfs
|
alpar@100
|
1234 |
/// class. It works with callback mechanism, the DfsVisit object calls
|
kpeter@244
|
1235 |
/// the member functions of the \c Visitor class on every DFS event.
|
alpar@100
|
1236 |
///
|
kpeter@252
|
1237 |
/// This interface of the DFS algorithm should be used in special cases
|
kpeter@252
|
1238 |
/// when extra actions have to be performed in connection with certain
|
kpeter@252
|
1239 |
/// events of the DFS algorithm. Otherwise consider to use Dfs or dfs()
|
kpeter@252
|
1240 |
/// instead.
|
kpeter@252
|
1241 |
///
|
kpeter@244
|
1242 |
/// \tparam _Digraph The type of the digraph the algorithm runs on.
|
alpar@210
|
1243 |
/// The default value is
|
kpeter@244
|
1244 |
/// \ref ListDigraph. The value of _Digraph is not used directly by
|
kpeter@244
|
1245 |
/// \ref DfsVisit, it is only passed to \ref DfsVisitDefaultTraits.
|
kpeter@244
|
1246 |
/// \tparam _Visitor The Visitor type that is used by the algorithm.
|
kpeter@244
|
1247 |
/// \ref DfsVisitor "DfsVisitor<_Digraph>" is an empty visitor, which
|
kpeter@244
|
1248 |
/// does not observe the DFS events. If you want to observe the DFS
|
kpeter@244
|
1249 |
/// events, you should implement your own visitor class.
|
alpar@209
|
1250 |
/// \tparam _Traits Traits class to set various data types used by the
|
alpar@100
|
1251 |
/// algorithm. The default traits class is
|
alpar@100
|
1252 |
/// \ref DfsVisitDefaultTraits "DfsVisitDefaultTraits<_Digraph>".
|
alpar@100
|
1253 |
/// See \ref DfsVisitDefaultTraits for the documentation of
|
kpeter@244
|
1254 |
/// a DFS visit traits class.
|
alpar@100
|
1255 |
#ifdef DOXYGEN
|
alpar@100
|
1256 |
template <typename _Digraph, typename _Visitor, typename _Traits>
|
alpar@100
|
1257 |
#else
|
alpar@100
|
1258 |
template <typename _Digraph = ListDigraph,
|
alpar@209
|
1259 |
typename _Visitor = DfsVisitor<_Digraph>,
|
deba@288
|
1260 |
typename _Traits = DfsVisitDefaultTraits<_Digraph> >
|
alpar@100
|
1261 |
#endif
|
alpar@100
|
1262 |
class DfsVisit {
|
alpar@100
|
1263 |
public:
|
alpar@209
|
1264 |
|
kpeter@244
|
1265 |
///The traits class.
|
alpar@100
|
1266 |
typedef _Traits Traits;
|
alpar@100
|
1267 |
|
kpeter@244
|
1268 |
///The type of the digraph the algorithm runs on.
|
alpar@100
|
1269 |
typedef typename Traits::Digraph Digraph;
|
alpar@100
|
1270 |
|
kpeter@244
|
1271 |
///The visitor type used by the algorithm.
|
alpar@100
|
1272 |
typedef _Visitor Visitor;
|
alpar@100
|
1273 |
|
kpeter@244
|
1274 |
///The type of the map that indicates which nodes are reached.
|
alpar@100
|
1275 |
typedef typename Traits::ReachedMap ReachedMap;
|
alpar@100
|
1276 |
|
alpar@100
|
1277 |
private:
|
alpar@100
|
1278 |
|
alpar@100
|
1279 |
typedef typename Digraph::Node Node;
|
alpar@100
|
1280 |
typedef typename Digraph::NodeIt NodeIt;
|
alpar@100
|
1281 |
typedef typename Digraph::Arc Arc;
|
alpar@100
|
1282 |
typedef typename Digraph::OutArcIt OutArcIt;
|
alpar@100
|
1283 |
|
kpeter@244
|
1284 |
//Pointer to the underlying digraph.
|
alpar@100
|
1285 |
const Digraph *_digraph;
|
kpeter@244
|
1286 |
//Pointer to the visitor object.
|
alpar@100
|
1287 |
Visitor *_visitor;
|
kpeter@244
|
1288 |
//Pointer to the map of reached status of the nodes.
|
alpar@100
|
1289 |
ReachedMap *_reached;
|
kpeter@244
|
1290 |
//Indicates if _reached is locally allocated (true) or not.
|
alpar@100
|
1291 |
bool local_reached;
|
alpar@100
|
1292 |
|
alpar@100
|
1293 |
std::vector<typename Digraph::Arc> _stack;
|
alpar@100
|
1294 |
int _stack_head;
|
alpar@100
|
1295 |
|
alpar@280
|
1296 |
//Creates the maps if necessary.
|
alpar@100
|
1297 |
void create_maps() {
|
alpar@100
|
1298 |
if(!_reached) {
|
alpar@209
|
1299 |
local_reached = true;
|
alpar@209
|
1300 |
_reached = Traits::createReachedMap(*_digraph);
|
alpar@100
|
1301 |
}
|
alpar@100
|
1302 |
}
|
alpar@100
|
1303 |
|
alpar@100
|
1304 |
protected:
|
alpar@100
|
1305 |
|
alpar@100
|
1306 |
DfsVisit() {}
|
alpar@209
|
1307 |
|
alpar@100
|
1308 |
public:
|
alpar@100
|
1309 |
|
alpar@100
|
1310 |
typedef DfsVisit Create;
|
alpar@100
|
1311 |
|
alpar@100
|
1312 |
/// \name Named template parameters
|
alpar@100
|
1313 |
|
alpar@100
|
1314 |
///@{
|
alpar@100
|
1315 |
template <class T>
|
kpeter@257
|
1316 |
struct SetReachedMapTraits : public Traits {
|
alpar@100
|
1317 |
typedef T ReachedMap;
|
alpar@100
|
1318 |
static ReachedMap *createReachedMap(const Digraph &digraph) {
|
deba@290
|
1319 |
LEMON_ASSERT(false, "ReachedMap is not initialized");
|
deba@290
|
1320 |
return 0; // ignore warnings
|
alpar@100
|
1321 |
}
|
alpar@100
|
1322 |
};
|
alpar@209
|
1323 |
/// \brief \ref named-templ-param "Named parameter" for setting
|
kpeter@244
|
1324 |
/// ReachedMap type.
|
alpar@100
|
1325 |
///
|
kpeter@244
|
1326 |
/// \ref named-templ-param "Named parameter" for setting ReachedMap type.
|
alpar@100
|
1327 |
template <class T>
|
kpeter@257
|
1328 |
struct SetReachedMap : public DfsVisit< Digraph, Visitor,
|
kpeter@257
|
1329 |
SetReachedMapTraits<T> > {
|
kpeter@257
|
1330 |
typedef DfsVisit< Digraph, Visitor, SetReachedMapTraits<T> > Create;
|
alpar@100
|
1331 |
};
|
alpar@100
|
1332 |
///@}
|
alpar@100
|
1333 |
|
alpar@209
|
1334 |
public:
|
alpar@209
|
1335 |
|
alpar@100
|
1336 |
/// \brief Constructor.
|
alpar@100
|
1337 |
///
|
alpar@100
|
1338 |
/// Constructor.
|
alpar@100
|
1339 |
///
|
kpeter@244
|
1340 |
/// \param digraph The digraph the algorithm runs on.
|
kpeter@244
|
1341 |
/// \param visitor The visitor object of the algorithm.
|
alpar@209
|
1342 |
DfsVisit(const Digraph& digraph, Visitor& visitor)
|
alpar@100
|
1343 |
: _digraph(&digraph), _visitor(&visitor),
|
alpar@209
|
1344 |
_reached(0), local_reached(false) {}
|
alpar@209
|
1345 |
|
alpar@100
|
1346 |
/// \brief Destructor.
|
alpar@100
|
1347 |
~DfsVisit() {
|
alpar@100
|
1348 |
if(local_reached) delete _reached;
|
alpar@100
|
1349 |
}
|
alpar@100
|
1350 |
|
kpeter@244
|
1351 |
/// \brief Sets the map that indicates which nodes are reached.
|
alpar@100
|
1352 |
///
|
kpeter@244
|
1353 |
/// Sets the map that indicates which nodes are reached.
|
alpar@100
|
1354 |
/// If you don't use this function before calling \ref run(),
|
kpeter@244
|
1355 |
/// it will allocate one. The destructor deallocates this
|
alpar@100
|
1356 |
/// automatically allocated map, of course.
|
alpar@100
|
1357 |
/// \return <tt> (*this) </tt>
|
alpar@100
|
1358 |
DfsVisit &reachedMap(ReachedMap &m) {
|
alpar@100
|
1359 |
if(local_reached) {
|
alpar@209
|
1360 |
delete _reached;
|
alpar@209
|
1361 |
local_reached=false;
|
alpar@100
|
1362 |
}
|
alpar@100
|
1363 |
_reached = &m;
|
alpar@100
|
1364 |
return *this;
|
alpar@100
|
1365 |
}
|
alpar@100
|
1366 |
|
alpar@100
|
1367 |
public:
|
kpeter@244
|
1368 |
|
alpar@100
|
1369 |
/// \name Execution control
|
alpar@100
|
1370 |
/// The simplest way to execute the algorithm is to use
|
kpeter@244
|
1371 |
/// one of the member functions called \ref lemon::DfsVisit::run()
|
kpeter@244
|
1372 |
/// "run()".
|
alpar@100
|
1373 |
/// \n
|
kpeter@244
|
1374 |
/// If you need more control on the execution, first you must call
|
kpeter@244
|
1375 |
/// \ref lemon::DfsVisit::init() "init()", then you can add several
|
kpeter@244
|
1376 |
/// source nodes with \ref lemon::DfsVisit::addSource() "addSource()".
|
kpeter@244
|
1377 |
/// Finally \ref lemon::DfsVisit::start() "start()" will perform the
|
kpeter@244
|
1378 |
/// actual path computation.
|
alpar@100
|
1379 |
|
alpar@100
|
1380 |
/// @{
|
kpeter@244
|
1381 |
|
alpar@100
|
1382 |
/// \brief Initializes the internal data structures.
|
alpar@100
|
1383 |
///
|
alpar@100
|
1384 |
/// Initializes the internal data structures.
|
alpar@100
|
1385 |
void init() {
|
alpar@100
|
1386 |
create_maps();
|
alpar@100
|
1387 |
_stack.resize(countNodes(*_digraph));
|
alpar@100
|
1388 |
_stack_head = -1;
|
alpar@100
|
1389 |
for (NodeIt u(*_digraph) ; u != INVALID ; ++u) {
|
alpar@209
|
1390 |
_reached->set(u, false);
|
alpar@100
|
1391 |
}
|
alpar@100
|
1392 |
}
|
alpar@209
|
1393 |
|
kpeter@244
|
1394 |
///Adds a new source node.
|
kpeter@244
|
1395 |
|
kpeter@244
|
1396 |
///Adds a new source node to the set of nodes to be processed.
|
alpar@100
|
1397 |
///
|
kpeter@244
|
1398 |
///\pre The stack must be empty. (Otherwise the algorithm gives
|
kpeter@244
|
1399 |
///false results.)
|
kpeter@244
|
1400 |
///
|
kpeter@244
|
1401 |
///\warning Distances will be wrong (or at least strange) in case of
|
kpeter@244
|
1402 |
///multiple sources.
|
kpeter@244
|
1403 |
void addSource(Node s)
|
kpeter@244
|
1404 |
{
|
kpeter@244
|
1405 |
LEMON_DEBUG(emptyQueue(), "The stack is not empty.");
|
alpar@100
|
1406 |
if(!(*_reached)[s]) {
|
alpar@209
|
1407 |
_reached->set(s,true);
|
alpar@209
|
1408 |
_visitor->start(s);
|
alpar@209
|
1409 |
_visitor->reach(s);
|
alpar@209
|
1410 |
Arc e;
|
alpar@209
|
1411 |
_digraph->firstOut(e, s);
|
alpar@209
|
1412 |
if (e != INVALID) {
|
alpar@209
|
1413 |
_stack[++_stack_head] = e;
|
alpar@209
|
1414 |
} else {
|
alpar@209
|
1415 |
_visitor->leave(s);
|
alpar@344
|
1416 |
_visitor->stop(s);
|
alpar@209
|
1417 |
}
|
alpar@209
|
1418 |
}
|
alpar@100
|
1419 |
}
|
alpar@209
|
1420 |
|
alpar@100
|
1421 |
/// \brief Processes the next arc.
|
alpar@100
|
1422 |
///
|
alpar@100
|
1423 |
/// Processes the next arc.
|
alpar@100
|
1424 |
///
|
alpar@100
|
1425 |
/// \return The processed arc.
|
alpar@100
|
1426 |
///
|
kpeter@244
|
1427 |
/// \pre The stack must not be empty.
|
alpar@209
|
1428 |
Arc processNextArc() {
|
alpar@100
|
1429 |
Arc e = _stack[_stack_head];
|
alpar@100
|
1430 |
Node m = _digraph->target(e);
|
alpar@100
|
1431 |
if(!(*_reached)[m]) {
|
alpar@209
|
1432 |
_visitor->discover(e);
|
alpar@209
|
1433 |
_visitor->reach(m);
|
alpar@209
|
1434 |
_reached->set(m, true);
|
alpar@209
|
1435 |
_digraph->firstOut(_stack[++_stack_head], m);
|
alpar@100
|
1436 |
} else {
|
alpar@209
|
1437 |
_visitor->examine(e);
|
alpar@209
|
1438 |
m = _digraph->source(e);
|
alpar@209
|
1439 |
_digraph->nextOut(_stack[_stack_head]);
|
alpar@100
|
1440 |
}
|
alpar@100
|
1441 |
while (_stack_head>=0 && _stack[_stack_head] == INVALID) {
|
alpar@209
|
1442 |
_visitor->leave(m);
|
alpar@209
|
1443 |
--_stack_head;
|
alpar@209
|
1444 |
if (_stack_head >= 0) {
|
alpar@209
|
1445 |
_visitor->backtrack(_stack[_stack_head]);
|
alpar@209
|
1446 |
m = _digraph->source(_stack[_stack_head]);
|
alpar@209
|
1447 |
_digraph->nextOut(_stack[_stack_head]);
|
alpar@209
|
1448 |
} else {
|
alpar@209
|
1449 |
_visitor->stop(m);
|
alpar@209
|
1450 |
}
|
alpar@100
|
1451 |
}
|
alpar@100
|
1452 |
return e;
|
alpar@100
|
1453 |
}
|
alpar@100
|
1454 |
|
alpar@100
|
1455 |
/// \brief Next arc to be processed.
|
alpar@100
|
1456 |
///
|
alpar@100
|
1457 |
/// Next arc to be processed.
|
alpar@100
|
1458 |
///
|
alpar@100
|
1459 |
/// \return The next arc to be processed or INVALID if the stack is
|
alpar@100
|
1460 |
/// empty.
|
kpeter@244
|
1461 |
Arc nextArc() const {
|
alpar@100
|
1462 |
return _stack_head >= 0 ? _stack[_stack_head] : INVALID;
|
alpar@100
|
1463 |
}
|
alpar@100
|
1464 |
|
alpar@100
|
1465 |
/// \brief Returns \c false if there are nodes
|
kpeter@244
|
1466 |
/// to be processed.
|
alpar@100
|
1467 |
///
|
alpar@100
|
1468 |
/// Returns \c false if there are nodes
|
kpeter@244
|
1469 |
/// to be processed in the queue (stack).
|
kpeter@244
|
1470 |
bool emptyQueue() const { return _stack_head < 0; }
|
alpar@100
|
1471 |
|
alpar@100
|
1472 |
/// \brief Returns the number of the nodes to be processed.
|
alpar@100
|
1473 |
///
|
kpeter@244
|
1474 |
/// Returns the number of the nodes to be processed in the queue (stack).
|
kpeter@244
|
1475 |
int queueSize() const { return _stack_head + 1; }
|
alpar@209
|
1476 |
|
alpar@100
|
1477 |
/// \brief Executes the algorithm.
|
alpar@100
|
1478 |
///
|
alpar@100
|
1479 |
/// Executes the algorithm.
|
alpar@100
|
1480 |
///
|
kpeter@244
|
1481 |
/// This method runs the %DFS algorithm from the root node
|
kpeter@244
|
1482 |
/// in order to compute the %DFS path to each node.
|
kpeter@244
|
1483 |
///
|
kpeter@244
|
1484 |
/// The algorithm computes
|
kpeter@244
|
1485 |
/// - the %DFS tree,
|
kpeter@244
|
1486 |
/// - the distance of each node from the root in the %DFS tree.
|
kpeter@244
|
1487 |
///
|
kpeter@244
|
1488 |
/// \pre init() must be called and a root node should be
|
kpeter@244
|
1489 |
/// added with addSource() before using this function.
|
kpeter@244
|
1490 |
///
|
kpeter@244
|
1491 |
/// \note <tt>d.start()</tt> is just a shortcut of the following code.
|
kpeter@244
|
1492 |
/// \code
|
kpeter@244
|
1493 |
/// while ( !d.emptyQueue() ) {
|
kpeter@244
|
1494 |
/// d.processNextArc();
|
kpeter@244
|
1495 |
/// }
|
kpeter@244
|
1496 |
/// \endcode
|
alpar@100
|
1497 |
void start() {
|
alpar@100
|
1498 |
while ( !emptyQueue() ) processNextArc();
|
alpar@100
|
1499 |
}
|
alpar@209
|
1500 |
|
kpeter@244
|
1501 |
/// \brief Executes the algorithm until the given target node is reached.
|
alpar@100
|
1502 |
///
|
kpeter@244
|
1503 |
/// Executes the algorithm until the given target node is reached.
|
alpar@100
|
1504 |
///
|
kpeter@244
|
1505 |
/// This method runs the %DFS algorithm from the root node
|
kpeter@286
|
1506 |
/// in order to compute the DFS path to \c t.
|
kpeter@244
|
1507 |
///
|
kpeter@244
|
1508 |
/// The algorithm computes
|
kpeter@286
|
1509 |
/// - the %DFS path to \c t,
|
kpeter@286
|
1510 |
/// - the distance of \c t from the root in the %DFS tree.
|
kpeter@244
|
1511 |
///
|
kpeter@244
|
1512 |
/// \pre init() must be called and a root node should be added
|
alpar@100
|
1513 |
/// with addSource() before using this function.
|
kpeter@286
|
1514 |
void start(Node t) {
|
kpeter@286
|
1515 |
while ( !emptyQueue() && _digraph->target(_stack[_stack_head]) != t )
|
alpar@209
|
1516 |
processNextArc();
|
alpar@100
|
1517 |
}
|
alpar@209
|
1518 |
|
alpar@100
|
1519 |
/// \brief Executes the algorithm until a condition is met.
|
alpar@100
|
1520 |
///
|
alpar@100
|
1521 |
/// Executes the algorithm until a condition is met.
|
alpar@100
|
1522 |
///
|
kpeter@244
|
1523 |
/// This method runs the %DFS algorithm from the root node
|
kpeter@244
|
1524 |
/// until an arc \c a with <tt>am[a]</tt> true is found.
|
kpeter@244
|
1525 |
///
|
kpeter@244
|
1526 |
/// \param am A \c bool (or convertible) arc map. The algorithm
|
kpeter@244
|
1527 |
/// will stop when it reaches an arc \c a with <tt>am[a]</tt> true.
|
kpeter@244
|
1528 |
///
|
kpeter@244
|
1529 |
/// \return The reached arc \c a with <tt>am[a]</tt> true or
|
kpeter@244
|
1530 |
/// \c INVALID if no such arc was found.
|
kpeter@244
|
1531 |
///
|
kpeter@244
|
1532 |
/// \pre init() must be called and a root node should be added
|
alpar@100
|
1533 |
/// with addSource() before using this function.
|
alpar@100
|
1534 |
///
|
kpeter@244
|
1535 |
/// \warning Contrary to \ref Bfs and \ref Dijkstra, \c am is an arc map,
|
alpar@100
|
1536 |
/// not a node map.
|
kpeter@244
|
1537 |
template <typename AM>
|
kpeter@244
|
1538 |
Arc start(const AM &am) {
|
kpeter@244
|
1539 |
while ( !emptyQueue() && !am[_stack[_stack_head]] )
|
alpar@100
|
1540 |
processNextArc();
|
alpar@100
|
1541 |
return emptyQueue() ? INVALID : _stack[_stack_head];
|
alpar@100
|
1542 |
}
|
alpar@100
|
1543 |
|
kpeter@286
|
1544 |
/// \brief Runs the algorithm from the given source node.
|
alpar@100
|
1545 |
///
|
kpeter@244
|
1546 |
/// This method runs the %DFS algorithm from node \c s.
|
kpeter@244
|
1547 |
/// in order to compute the DFS path to each node.
|
kpeter@244
|
1548 |
///
|
kpeter@244
|
1549 |
/// The algorithm computes
|
kpeter@244
|
1550 |
/// - the %DFS tree,
|
kpeter@244
|
1551 |
/// - the distance of each node from the root in the %DFS tree.
|
kpeter@244
|
1552 |
///
|
kpeter@244
|
1553 |
/// \note <tt>d.run(s)</tt> is just a shortcut of the following code.
|
alpar@100
|
1554 |
///\code
|
alpar@100
|
1555 |
/// d.init();
|
alpar@100
|
1556 |
/// d.addSource(s);
|
alpar@100
|
1557 |
/// d.start();
|
alpar@100
|
1558 |
///\endcode
|
alpar@100
|
1559 |
void run(Node s) {
|
alpar@100
|
1560 |
init();
|
alpar@100
|
1561 |
addSource(s);
|
alpar@100
|
1562 |
start();
|
alpar@100
|
1563 |
}
|
alpar@100
|
1564 |
|
kpeter@244
|
1565 |
/// \brief Finds the %DFS path between \c s and \c t.
|
kpeter@244
|
1566 |
|
kpeter@244
|
1567 |
/// This method runs the %DFS algorithm from node \c s
|
kpeter@286
|
1568 |
/// in order to compute the DFS path to node \c t
|
kpeter@286
|
1569 |
/// (it stops searching when \c t is processed).
|
kpeter@244
|
1570 |
///
|
kpeter@286
|
1571 |
/// \return \c true if \c t is reachable form \c s.
|
kpeter@244
|
1572 |
///
|
kpeter@244
|
1573 |
/// \note Apart from the return value, <tt>d.run(s,t)</tt> is
|
kpeter@244
|
1574 |
/// just a shortcut of the following code.
|
kpeter@244
|
1575 |
///\code
|
kpeter@244
|
1576 |
/// d.init();
|
kpeter@244
|
1577 |
/// d.addSource(s);
|
kpeter@244
|
1578 |
/// d.start(t);
|
kpeter@244
|
1579 |
///\endcode
|
kpeter@286
|
1580 |
bool run(Node s,Node t) {
|
kpeter@244
|
1581 |
init();
|
kpeter@244
|
1582 |
addSource(s);
|
kpeter@244
|
1583 |
start(t);
|
kpeter@286
|
1584 |
return reached(t);
|
kpeter@244
|
1585 |
}
|
kpeter@244
|
1586 |
|
kpeter@244
|
1587 |
/// \brief Runs the algorithm to visit all nodes in the digraph.
|
alpar@209
|
1588 |
|
alpar@100
|
1589 |
/// This method runs the %DFS algorithm in order to
|
kpeter@244
|
1590 |
/// compute the %DFS path to each node.
|
alpar@100
|
1591 |
///
|
kpeter@244
|
1592 |
/// The algorithm computes
|
kpeter@244
|
1593 |
/// - the %DFS tree,
|
kpeter@244
|
1594 |
/// - the distance of each node from the root in the %DFS tree.
|
kpeter@244
|
1595 |
///
|
kpeter@244
|
1596 |
/// \note <tt>d.run()</tt> is just a shortcut of the following code.
|
alpar@100
|
1597 |
///\code
|
kpeter@244
|
1598 |
/// d.init();
|
kpeter@244
|
1599 |
/// for (NodeIt n(digraph); n != INVALID; ++n) {
|
kpeter@244
|
1600 |
/// if (!d.reached(n)) {
|
kpeter@244
|
1601 |
/// d.addSource(n);
|
kpeter@244
|
1602 |
/// d.start();
|
kpeter@244
|
1603 |
/// }
|
kpeter@244
|
1604 |
/// }
|
alpar@100
|
1605 |
///\endcode
|
alpar@100
|
1606 |
void run() {
|
alpar@100
|
1607 |
init();
|
alpar@100
|
1608 |
for (NodeIt it(*_digraph); it != INVALID; ++it) {
|
alpar@100
|
1609 |
if (!reached(it)) {
|
alpar@100
|
1610 |
addSource(it);
|
alpar@100
|
1611 |
start();
|
alpar@100
|
1612 |
}
|
alpar@100
|
1613 |
}
|
alpar@100
|
1614 |
}
|
kpeter@244
|
1615 |
|
alpar@100
|
1616 |
///@}
|
alpar@100
|
1617 |
|
alpar@100
|
1618 |
/// \name Query Functions
|
alpar@100
|
1619 |
/// The result of the %DFS algorithm can be obtained using these
|
alpar@100
|
1620 |
/// functions.\n
|
kpeter@244
|
1621 |
/// Either \ref lemon::DfsVisit::run() "run()" or
|
kpeter@244
|
1622 |
/// \ref lemon::DfsVisit::start() "start()" must be called before
|
kpeter@244
|
1623 |
/// using them.
|
alpar@100
|
1624 |
///@{
|
kpeter@244
|
1625 |
|
kpeter@244
|
1626 |
/// \brief Checks if a node is reachable from the root(s).
|
alpar@100
|
1627 |
///
|
alpar@100
|
1628 |
/// Returns \c true if \c v is reachable from the root(s).
|
alpar@100
|
1629 |
/// \pre Either \ref run() or \ref start()
|
alpar@100
|
1630 |
/// must be called before using this function.
|
alpar@100
|
1631 |
bool reached(Node v) { return (*_reached)[v]; }
|
kpeter@244
|
1632 |
|
alpar@100
|
1633 |
///@}
|
kpeter@244
|
1634 |
|
alpar@100
|
1635 |
};
|
alpar@100
|
1636 |
|
alpar@100
|
1637 |
} //END OF NAMESPACE LEMON
|
alpar@100
|
1638 |
|
alpar@100
|
1639 |
#endif
|