# HG changeset patch # User deba # Date 1136304327 0 # Node ID b9c9b52f839ec8fdd4e6651762bc39f2b1df3a4a # Parent 52f5a7f9fb489fbcf69b9ce4b50458227e0d08ec Delete misnamed file diff -r 52f5a7f9fb48 -r b9c9b52f839e lemon/belmann_ford.h --- a/lemon/belmann_ford.h Tue Jan 03 14:56:45 2006 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,950 +0,0 @@ -/* -*- C++ -*- - * lemon/belmann_ford.h - Part of LEMON, a generic C++ optimization library - * - * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport - * (Egervary Research Group on Combinatorial Optimization, EGRES). - * - * Permission to use, modify and distribute this software is granted - * provided that this copyright notice appears in all copies. For - * precise terms see the accompanying LICENSE file. - * - * This software is provided "AS IS" with no warranty of any kind, - * express or implied, and with no claim as to its suitability for any - * purpose. - * - */ - -#ifndef LEMON_BELMANN_FORD_H -#define LEMON_BELMANN_FORD_H - -/// \ingroup flowalgs -/// \file -/// \brief BelmannFord algorithm. -/// - -#include -#include -#include -#include - -#include - -namespace lemon { - - /// \brief Default OperationTraits for the BelmannFord algorithm class. - /// - /// It defines all computational operations and constants which are - /// used in the belmann ford algorithm. The default implementation - /// is based on the numeric_limits class. If the numeric type does not - /// have infinity value then the maximum value is used as extremal - /// infinity value. - template < - typename Value, - bool has_infinity = std::numeric_limits::has_infinity> - struct BelmannFordDefaultOperationTraits { - /// \brief Gives back the zero value of the type. - static Value zero() { - return static_cast(0); - } - /// \brief Gives back the positive infinity value of the type. - static Value infinity() { - return std::numeric_limits::infinity(); - } - /// \brief Gives back the sum of the given two elements. - static Value plus(const Value& left, const Value& right) { - return left + right; - } - /// \brief Gives back true only if the first value less than the second. - static bool less(const Value& left, const Value& right) { - return left < right; - } - }; - - template - struct BelmannFordDefaultOperationTraits { - static Value zero() { - return static_cast(0); - } - static Value infinity() { - return std::numeric_limits::max(); - } - static Value plus(const Value& left, const Value& right) { - if (left == infinity() || right == infinity()) return infinity(); - return left + right; - } - static bool less(const Value& left, const Value& right) { - return left < right; - } - }; - - /// \brief Default traits class of BelmannFord class. - /// - /// Default traits class of BelmannFord class. - /// \param _Graph Graph type. - /// \param _LegthMap Type of length map. - template - struct BelmannFordDefaultTraits { - /// The graph type the algorithm runs on. - typedef _Graph Graph; - - /// \brief The type of the map that stores the edge lengths. - /// - /// The type of the map that stores the edge lengths. - /// It must meet the \ref concept::ReadMap "ReadMap" concept. - typedef _LengthMap LengthMap; - - // The type of the length of the edges. - typedef typename _LengthMap::Value Value; - - /// \brief Operation traits for belmann-ford algorithm. - /// - /// It defines the infinity type on the given Value type - /// and the used operation. - /// \see BelmannFordDefaultOperationTraits - typedef BelmannFordDefaultOperationTraits OperationTraits; - - /// \brief The type of the map that stores the last edges of the - /// shortest paths. - /// - /// The type of the map that stores the last - /// edges of the shortest paths. - /// It must meet the \ref concept::WriteMap "WriteMap" concept. - /// - typedef typename Graph::template NodeMap PredMap; - - /// \brief Instantiates a PredMap. - /// - /// This function instantiates a \ref PredMap. - /// \param graph is the graph, to which we would like to define the PredMap. - static PredMap *createPredMap(const _Graph& graph) { - return new PredMap(graph); - } - - /// \brief The type of the map that stores the dists of the nodes. - /// - /// The type of the map that stores the dists of the nodes. - /// It must meet the \ref concept::WriteMap "WriteMap" concept. - /// - typedef typename Graph::template NodeMap - DistMap; - - /// \brief Instantiates a DistMap. - /// - /// This function instantiates a \ref DistMap. - /// \param graph is the graph, to which we would like to define the - /// \ref DistMap - static DistMap *createDistMap(const _Graph& graph) { - return new DistMap(graph); - } - - }; - - /// \brief %BelmannFord algorithm class. - /// - /// \ingroup flowalgs - /// This class provides an efficient implementation of \c Belmann-Ford - /// algorithm. The edge lengths are passed to the algorithm using a - /// \ref concept::ReadMap "ReadMap", so it is easy to change it to any - /// kind of length. - /// - /// The Belmann-Ford algorithm solves the shortest path from one node - /// problem when the edges can have negative length but the graph should - /// not contain cycles with negative sum of length. If we can assume - /// that all edge is non-negative in the graph then the dijkstra algorithm - /// should be used rather. - /// - /// The complexity of the algorithm is O(n * e). - /// - /// The type of the length is determined by the - /// \ref concept::ReadMap::Value "Value" of the length map. - /// - /// \param _Graph The graph type the algorithm runs on. The default value - /// is \ref ListGraph. The value of _Graph is not used directly by - /// BelmannFord, it is only passed to \ref BelmannFordDefaultTraits. - /// \param _LengthMap This read-only EdgeMap determines the lengths of the - /// edges. The default map type is \ref concept::StaticGraph::EdgeMap - /// "Graph::EdgeMap". The value of _LengthMap is not used directly - /// by BelmannFord, it is only passed to \ref BelmannFordDefaultTraits. - /// \param _Traits Traits class to set various data types used by the - /// algorithm. The default traits class is \ref BelmannFordDefaultTraits - /// "BelmannFordDefaultTraits<_Graph,_LengthMap>". See \ref - /// BelmannFordDefaultTraits for the documentation of a BelmannFord traits - /// class. - /// - /// \author Balazs Dezso - -#ifdef DOXYGEN - template -#else - template , - typename _Traits=BelmannFordDefaultTraits<_Graph,_LengthMap> > -#endif - class BelmannFord { - public: - - /// \brief \ref Exception for uninitialized parameters. - /// - /// This error represents problems in the initialization - /// of the parameters of the algorithms. - - class UninitializedParameter : public lemon::UninitializedParameter { - public: - virtual const char* exceptionName() const { - return "lemon::BelmannFord::UninitializedParameter"; - } - }; - - typedef _Traits Traits; - ///The type of the underlying graph. - typedef typename _Traits::Graph Graph; - - typedef typename Graph::Node Node; - typedef typename Graph::NodeIt NodeIt; - typedef typename Graph::Edge Edge; - typedef typename Graph::OutEdgeIt OutEdgeIt; - - /// \brief The type of the length of the edges. - typedef typename _Traits::LengthMap::Value Value; - /// \brief The type of the map that stores the edge lengths. - typedef typename _Traits::LengthMap LengthMap; - /// \brief The type of the map that stores the last - /// edges of the shortest paths. - typedef typename _Traits::PredMap PredMap; - /// \brief The type of the map that stores the dists of the nodes. - typedef typename _Traits::DistMap DistMap; - /// \brief The operation traits. - typedef typename _Traits::OperationTraits OperationTraits; - private: - /// Pointer to the underlying graph. - const Graph *graph; - /// Pointer to the length map - const LengthMap *length; - ///Pointer to the map of predecessors edges. - PredMap *_pred; - ///Indicates if \ref _pred is locally allocated (\c true) or not. - bool local_pred; - ///Pointer to the map of distances. - DistMap *_dist; - ///Indicates if \ref _dist is locally allocated (\c true) or not. - bool local_dist; - - typedef typename Graph::template NodeMap MaskMap; - MaskMap *_mask; - - std::vector _process; - - /// Creates the maps if necessary. - void create_maps() { - if(!_pred) { - local_pred = true; - _pred = Traits::createPredMap(*graph); - } - if(!_dist) { - local_dist = true; - _dist = Traits::createDistMap(*graph); - } - _mask = new MaskMap(*graph, false); - } - - public : - - typedef BelmannFord Create; - - /// \name Named template parameters - - ///@{ - - template - struct DefPredMapTraits : public Traits { - typedef T PredMap; - static PredMap *createPredMap(const Graph&) { - throw UninitializedParameter(); - } - }; - - /// \brief \ref named-templ-param "Named parameter" for setting PredMap - /// type - /// \ref named-templ-param "Named parameter" for setting PredMap type - /// - template - struct DefPredMap - : public BelmannFord< Graph, LengthMap, DefPredMapTraits > { - typedef BelmannFord< Graph, LengthMap, DefPredMapTraits > Create; - }; - - template - struct DefDistMapTraits : public Traits { - typedef T DistMap; - static DistMap *createDistMap(const Graph& graph) { - throw UninitializedParameter(); - } - }; - - /// \brief \ref named-templ-param "Named parameter" for setting DistMap - /// type - /// - /// \ref named-templ-param "Named parameter" for setting DistMap type - /// - template - struct DefDistMap - : public BelmannFord< Graph, LengthMap, DefDistMapTraits > { - typedef BelmannFord< Graph, LengthMap, DefDistMapTraits > Create; - }; - - template - struct DefOperationTraitsTraits : public Traits { - typedef T OperationTraits; - }; - - /// \brief \ref named-templ-param "Named parameter" for setting - /// OperationTraits type - /// - /// \ref named-templ-param "Named parameter" for setting OperationTraits - /// type - template - struct DefOperationTraits - : public BelmannFord< Graph, LengthMap, DefOperationTraitsTraits > { - typedef BelmannFord< Graph, LengthMap, DefOperationTraitsTraits > - Create; - }; - - ///@} - - protected: - - BelmannFord() {} - - public: - - /// \brief Constructor. - /// - /// \param _graph the graph the algorithm will run on. - /// \param _length the length map used by the algorithm. - BelmannFord(const Graph& _graph, const LengthMap& _length) : - graph(&_graph), length(&_length), - _pred(0), local_pred(false), - _dist(0), local_dist(false) {} - - ///Destructor. - ~BelmannFord() { - if(local_pred) delete _pred; - if(local_dist) delete _dist; - delete _mask; - } - - /// \brief Sets the length map. - /// - /// Sets the length map. - /// \return \c (*this) - BelmannFord &lengthMap(const LengthMap &m) { - length = &m; - return *this; - } - - /// \brief Sets the map storing the predecessor edges. - /// - /// Sets the map storing the predecessor edges. - /// If you don't use this function before calling \ref run(), - /// it will allocate one. The destuctor deallocates this - /// automatically allocated map, of course. - /// \return \c (*this) - BelmannFord &predMap(PredMap &m) { - if(local_pred) { - delete _pred; - local_pred=false; - } - _pred = &m; - return *this; - } - - /// \brief Sets the map storing the distances calculated by the algorithm. - /// - /// Sets the map storing the distances calculated by the algorithm. - /// If you don't use this function before calling \ref run(), - /// it will allocate one. The destuctor deallocates this - /// automatically allocated map, of course. - /// \return \c (*this) - BelmannFord &distMap(DistMap &m) { - if(local_dist) { - delete _dist; - local_dist=false; - } - _dist = &m; - return *this; - } - - /// \name Execution control - /// The simplest way to execute the algorithm is to use - /// one of the member functions called \c run(...). - /// \n - /// If you need more control on the execution, - /// first you must call \ref init(), then you can add several source nodes - /// with \ref addSource(). - /// Finally \ref start() will perform the actual path - /// computation. - - ///@{ - - /// \brief Initializes the internal data structures. - /// - /// Initializes the internal data structures. - void init(const Value value = OperationTraits::infinity()) { - create_maps(); - for (NodeIt it(*graph); it != INVALID; ++it) { - _pred->set(it, INVALID); - _dist->set(it, value); - } - _process.clear(); - if (OperationTraits::less(value, OperationTraits::infinity())) { - for (NodeIt it(*graph); it != INVALID; ++it) { - _process.push_back(it); - _mask->set(it, true); - } - } - } - - /// \brief Adds a new source node. - /// - /// The optional second parameter is the initial distance of the node. - /// It just sets the distance of the node to the given value. - void addSource(Node source, Value dst = OperationTraits::zero()) { - _dist->set(source, dst); - if (!(*_mask)[source]) { - _process.push_back(source); - _mask->set(source, true); - } - } - - /// \brief Executes one round from the belmann ford algorithm. - /// - /// If the algoritm calculated the distances in the previous round - /// strictly for all at most k length paths then it will calculate the - /// distances strictly for all at most k + 1 length paths. With k - /// iteration this function calculates the at most k length paths. - /// \return %True when the algorithm have not found more shorter paths. - bool processNextRound() { - for (int i = 0; i < (int)_process.size(); ++i) { - _mask->set(_process[i], false); - } - std::vector nextProcess; - std::vector values(_process.size()); - for (int i = 0; i < (int)_process.size(); ++i) { - values[i] = (*_dist)[_process[i]]; - } - for (int i = 0; i < (int)_process.size(); ++i) { - for (OutEdgeIt it(*graph, _process[i]); it != INVALID; ++it) { - Node target = graph->target(it); - Value relaxed = OperationTraits::plus(values[i], (*length)[it]); - if (OperationTraits::less(relaxed, (*_dist)[target])) { - _pred->set(target, it); - _dist->set(target, relaxed); - if (!(*_mask)[target]) { - _mask->set(target, true); - nextProcess.push_back(target); - } - } - } - } - _process.swap(nextProcess); - return _process.empty(); - } - - /// \brief Executes one weak round from the belmann ford algorithm. - /// - /// If the algorithm calculated the distances in the - /// previous round at least for all at most k length paths then it will - /// calculate the distances at least for all at most k + 1 length paths. - /// This function does not make it possible to calculate strictly the - /// at most k length minimal paths, this is why it is - /// called just weak round. - /// \return %True when the algorithm have not found more shorter paths. - bool processNextWeakRound() { - for (int i = 0; i < (int)_process.size(); ++i) { - _mask->set(_process[i], false); - } - std::vector nextProcess; - for (int i = 0; i < (int)_process.size(); ++i) { - for (OutEdgeIt it(*graph, _process[i]); it != INVALID; ++it) { - Node target = graph->target(it); - Value relaxed = - OperationTraits::plus((*_dist)[_process[i]], (*length)[it]); - if (OperationTraits::less(relaxed, (*_dist)[target])) { - _pred->set(target, it); - _dist->set(target, relaxed); - if (!(*_mask)[target]) { - _mask->set(target, true); - nextProcess.push_back(target); - } - } - } - } - _process.swap(nextProcess); - return _process.empty(); - } - - /// \brief Executes the algorithm. - /// - /// \pre init() must be called and at least one node should be added - /// with addSource() before using this function. - /// - /// This method runs the %BelmannFord algorithm from the root node(s) - /// in order to compute the shortest path to each node. The algorithm - /// computes - /// - The shortest path tree. - /// - The distance of each node from the root(s). - void start() { - int num = countNodes(*graph) - 1; - for (int i = 0; i < num; ++i) { - if (processNextWeakRound()) break; - } - } - - /// \brief Executes the algorithm and checks the negative cycles. - /// - /// \pre init() must be called and at least one node should be added - /// with addSource() before using this function. If there is - /// a negative cycles in the graph it gives back false. - /// - /// This method runs the %BelmannFord algorithm from the root node(s) - /// in order to compute the shortest path to each node. The algorithm - /// computes - /// - The shortest path tree. - /// - The distance of each node from the root(s). - bool checkedStart() { - int num = countNodes(*graph); - for (int i = 0; i < num; ++i) { - if (processNextWeakRound()) return true; - } - return false; - } - - /// \brief Executes the algorithm with path length limit. - /// - /// \pre init() must be called and at least one node should be added - /// with addSource() before using this function. - /// - /// This method runs the %BelmannFord algorithm from the root node(s) - /// in order to compute the shortest path with at most \c length edge - /// long paths to each node. The algorithm computes - /// - The shortest path tree. - /// - The limited distance of each node from the root(s). - void limitedStart(int length) { - for (int i = 0; i < length; ++i) { - if (processNextRound()) break; - } - } - - /// \brief Runs %BelmannFord algorithm from node \c s. - /// - /// This method runs the %BelmannFord algorithm from a root node \c s - /// in order to compute the shortest path to each node. The algorithm - /// computes - /// - The shortest path tree. - /// - The distance of each node from the root. - /// - /// \note d.run(s) is just a shortcut of the following code. - /// \code - /// d.init(); - /// d.addSource(s); - /// d.start(); - /// \endcode - void run(Node s) { - init(); - addSource(s); - start(); - } - - /// \brief Runs %BelmannFord algorithm with limited path length - /// from node \c s. - /// - /// This method runs the %BelmannFord algorithm from a root node \c s - /// in order to compute the shortest path with at most \c len edges - /// to each node. The algorithm computes - /// - The shortest path tree. - /// - The distance of each node from the root. - /// - /// \note d.run(s, len) is just a shortcut of the following code. - /// \code - /// d.init(); - /// d.addSource(s); - /// d.limitedStart(len); - /// \endcode - void run(Node s, int len) { - init(); - addSource(s); - limitedStart(len); - } - - ///@} - - /// \name Query Functions - /// The result of the %BelmannFord algorithm can be obtained using these - /// functions.\n - /// Before the use of these functions, - /// either run() or start() must be called. - - ///@{ - - /// \brief Copies the shortest path to \c t into \c p - /// - /// This function copies the shortest path to \c t into \c p. - /// If it \c t is a source itself or unreachable, then it does not - /// alter \c p. - /// - /// \return Returns \c true if a path to \c t was actually copied to \c p, - /// \c false otherwise. - /// \sa DirPath - template - bool getPath(Path &p, Node t) { - if(reached(t)) { - p.clear(); - typename Path::Builder b(p); - for(b.setStartNode(t);predEdge(t)!=INVALID;t=predNode(t)) - b.pushFront(predEdge(t)); - b.commit(); - return true; - } - return false; - } - - /// \brief The distance of a node from the root. - /// - /// Returns the distance of a node from the root. - /// \pre \ref run() must be called before using this function. - /// \warning If node \c v in unreachable from the root the return value - /// of this funcion is undefined. - Value dist(Node v) const { return (*_dist)[v]; } - - /// \brief Returns the 'previous edge' of the shortest path tree. - /// - /// For a node \c v it returns the 'previous edge' of the shortest path - /// tree, i.e. it returns the last edge of a shortest path from the root - /// to \c v. It is \ref INVALID if \c v is unreachable from the root or - /// if \c v=s. The shortest path tree used here is equal to the shortest - /// path tree used in \ref predNode(). - /// \pre \ref run() must be called before using - /// this function. - Edge predEdge(Node v) const { return (*_pred)[v]; } - - /// \brief Returns the 'previous node' of the shortest path tree. - /// - /// For a node \c v it returns the 'previous node' of the shortest path - /// tree, i.e. it returns the last but one node from a shortest path from - /// the root to \c /v. It is INVALID if \c v is unreachable from the root - /// or if \c v=s. The shortest path tree used here is equal to the - /// shortest path tree used in \ref predEdge(). \pre \ref run() must be - /// called before using this function. - Node predNode(Node v) const { - return (*_pred)[v] == INVALID ? INVALID : graph->source((*_pred)[v]); - } - - /// \brief Returns a reference to the NodeMap of distances. - /// - /// Returns a reference to the NodeMap of distances. \pre \ref run() must - /// be called before using this function. - const DistMap &distMap() const { return *_dist;} - - /// \brief Returns a reference to the shortest path tree map. - /// - /// Returns a reference to the NodeMap of the edges of the - /// shortest path tree. - /// \pre \ref run() must be called before using this function. - const PredMap &predMap() const { return *_pred; } - - /// \brief Checks if a node is reachable from the root. - /// - /// Returns \c true if \c v is reachable from the root. - /// \pre \ref run() must be called before using this function. - /// - bool reached(Node v) { return (*_dist)[v] != OperationTraits::infinity(); } - - ///@} - }; - - /// \brief Default traits class of BelmannFord function. - /// - /// Default traits class of BelmannFord function. - /// \param _Graph Graph type. - /// \param _LengthMap Type of length map. - template - struct BelmannFordWizardDefaultTraits { - /// \brief The graph type the algorithm runs on. - typedef _Graph Graph; - - /// \brief The type of the map that stores the edge lengths. - /// - /// The type of the map that stores the edge lengths. - /// It must meet the \ref concept::ReadMap "ReadMap" concept. - typedef _LengthMap LengthMap; - - /// \brief The value type of the length map. - typedef typename _LengthMap::Value Value; - - /// \brief Operation traits for belmann-ford algorithm. - /// - /// It defines the infinity type on the given Value type - /// and the used operation. - /// \see BelmannFordDefaultOperationTraits - typedef BelmannFordDefaultOperationTraits OperationTraits; - - /// \brief The type of the map that stores the last - /// edges of the shortest paths. - /// - /// The type of the map that stores the last - /// edges of the shortest paths. - /// It must meet the \ref concept::WriteMap "WriteMap" concept. - typedef NullMap PredMap; - - /// \brief Instantiates a PredMap. - /// - /// This function instantiates a \ref PredMap. - static PredMap *createPredMap(const _Graph &) { - return new PredMap(); - } - /// \brief The type of the map that stores the dists of the nodes. - /// - /// The type of the map that stores the dists of the nodes. - /// It must meet the \ref concept::WriteMap "WriteMap" concept. - typedef NullMap DistMap; - /// \brief Instantiates a DistMap. - /// - /// This function instantiates a \ref DistMap. - static DistMap *createDistMap(const _Graph &) { - return new DistMap(); - } - }; - - /// \brief Default traits used by \ref BelmannFordWizard - /// - /// To make it easier to use BelmannFord algorithm - /// we have created a wizard class. - /// This \ref BelmannFordWizard class needs default traits, - /// as well as the \ref BelmannFord class. - /// The \ref BelmannFordWizardBase is a class to be the default traits of the - /// \ref BelmannFordWizard class. - /// \todo More named parameters are required... - template - class BelmannFordWizardBase - : public BelmannFordWizardDefaultTraits<_Graph,_LengthMap> { - - typedef BelmannFordWizardDefaultTraits<_Graph,_LengthMap> Base; - protected: - /// Type of the nodes in the graph. - typedef typename Base::Graph::Node Node; - - /// Pointer to the underlying graph. - void *_graph; - /// Pointer to the length map - void *_length; - ///Pointer to the map of predecessors edges. - void *_pred; - ///Pointer to the map of distances. - void *_dist; - ///Pointer to the source node. - Node _source; - - public: - /// Constructor. - - /// This constructor does not require parameters, therefore it initiates - /// all of the attributes to default values (0, INVALID). - BelmannFordWizardBase() : _graph(0), _length(0), _pred(0), - _dist(0), _source(INVALID) {} - - /// Constructor. - - /// This constructor requires some parameters, - /// listed in the parameters list. - /// Others are initiated to 0. - /// \param graph is the initial value of \ref _graph - /// \param length is the initial value of \ref _length - /// \param source is the initial value of \ref _source - BelmannFordWizardBase(const _Graph& graph, - const _LengthMap& length, - Node source = INVALID) : - _graph((void *)&graph), _length((void *)&length), _pred(0), - _dist(0), _source(source) {} - - }; - - /// A class to make the usage of BelmannFord algorithm easier - - /// This class is created to make it easier to use BelmannFord algorithm. - /// It uses the functions and features of the plain \ref BelmannFord, - /// but it is much simpler to use it. - /// - /// Simplicity means that the way to change the types defined - /// in the traits class is based on functions that returns the new class - /// and not on templatable built-in classes. - /// When using the plain \ref BelmannFord - /// the new class with the modified type comes from - /// the original class by using the :: - /// operator. In the case of \ref BelmannFordWizard only - /// a function have to be called and it will - /// return the needed class. - /// - /// It does not have own \ref run method. When its \ref run method is called - /// it initiates a plain \ref BelmannFord class, and calls the \ref - /// BelmannFord::run method of it. - template - class BelmannFordWizard : public _Traits { - typedef _Traits Base; - - ///The type of the underlying graph. - typedef typename _Traits::Graph Graph; - - typedef typename Graph::Node Node; - typedef typename Graph::NodeIt NodeIt; - typedef typename Graph::Edge Edge; - typedef typename Graph::OutEdgeIt EdgeIt; - - ///The type of the map that stores the edge lengths. - typedef typename _Traits::LengthMap LengthMap; - - ///The type of the length of the edges. - typedef typename LengthMap::Value Value; - - ///\brief The type of the map that stores the last - ///edges of the shortest paths. - typedef typename _Traits::PredMap PredMap; - - ///The type of the map that stores the dists of the nodes. - typedef typename _Traits::DistMap DistMap; - - public: - /// Constructor. - BelmannFordWizard() : _Traits() {} - - /// \brief Constructor that requires parameters. - /// - /// Constructor that requires parameters. - /// These parameters will be the default values for the traits class. - BelmannFordWizard(const Graph& graph, const LengthMap& length, - Node source = INVALID) - : _Traits(graph, length, source) {} - - /// \brief Copy constructor - BelmannFordWizard(const _Traits &b) : _Traits(b) {} - - ~BelmannFordWizard() {} - - /// \brief Runs BelmannFord algorithm from a given node. - /// - /// Runs BelmannFord algorithm from a given node. - /// The node can be given by the \ref source function. - void run() { - if(Base::_source == INVALID) throw UninitializedParameter(); - BelmannFord - bf(*(Graph*)Base::_graph, *(LengthMap*)Base::_length); - if (Base::_pred) bf.predMap(*(PredMap*)Base::_pred); - if (Base::_dist) bf.distMap(*(DistMap*)Base::_dist); - bf.run(Base::_source); - } - - /// \brief Runs BelmannFord algorithm from the given node. - /// - /// Runs BelmannFord algorithm from the given node. - /// \param source is the given source. - void run(Node source) { - Base::_source = source; - run(); - } - - template - struct DefPredMapBase : public Base { - typedef T PredMap; - static PredMap *createPredMap(const Graph &) { return 0; }; - DefPredMapBase(const _Traits &b) : _Traits(b) {} - }; - - ///\brief \ref named-templ-param "Named parameter" - ///function for setting PredMap type - /// - /// \ref named-templ-param "Named parameter" - ///function for setting PredMap type - /// - template - BelmannFordWizard > predMap(const T &t) - { - Base::_pred=(void *)&t; - return BelmannFordWizard >(*this); - } - - template - struct DefDistMapBase : public Base { - typedef T DistMap; - static DistMap *createDistMap(const Graph &) { return 0; }; - DefDistMapBase(const _Traits &b) : _Traits(b) {} - }; - - ///\brief \ref named-templ-param "Named parameter" - ///function for setting DistMap type - /// - /// \ref named-templ-param "Named parameter" - ///function for setting DistMap type - /// - template - BelmannFordWizard > distMap(const T &t) { - Base::_dist=(void *)&t; - return BelmannFordWizard >(*this); - } - - template - struct DefOperationTraitsBase : public Base { - typedef T OperationTraits; - DefOperationTraitsBase(const _Traits &b) : _Traits(b) {} - }; - - ///\brief \ref named-templ-param "Named parameter" - ///function for setting OperationTraits type - /// - /// \ref named-templ-param "Named parameter" - ///function for setting OperationTraits type - /// - template - BelmannFordWizard > distMap() { - return BelmannFordWizard >(*this); - } - - /// \brief Sets the source node, from which the BelmannFord algorithm runs. - /// - /// Sets the source node, from which the BelmannFord algorithm runs. - /// \param source is the source node. - BelmannFordWizard<_Traits>& source(Node source) { - Base::_source = source; - return *this; - } - - }; - - /// \brief Function type interface for BelmannFord algorithm. - /// - /// \ingroup flowalgs - /// Function type interface for BelmannFord algorithm. - /// - /// This function also has several \ref named-templ-func-param - /// "named parameters", they are declared as the members of class - /// \ref BelmannFordWizard. - /// The following - /// example shows how to use these parameters. - /// \code - /// belmannford(g,length,source).predMap(preds).run(); - /// \endcode - /// \warning Don't forget to put the \ref BelmannFordWizard::run() "run()" - /// to the end of the parameter list. - /// \sa BelmannFordWizard - /// \sa BelmannFord - template - BelmannFordWizard > - belmannFord(const _Graph& graph, - const _LengthMap& length, - typename _Graph::Node source = INVALID) { - return BelmannFordWizard > - (graph, length, source); - } - -} //END OF NAMESPACE LEMON - -#endif -