[Lemon-commits] [lemon_svn] deba: r2487 - hugo/trunk/lemon
Lemon SVN
svn at lemon.cs.elte.hu
Mon Nov 6 20:53:04 CET 2006
Author: deba
Date: Fri Jan 27 09:17:25 2006
New Revision: 2487
Added:
hugo/trunk/lemon/dag_shortest_path.h
hugo/trunk/lemon/fredman_tarjan.h
hugo/trunk/lemon/prim.h
Modified:
hugo/trunk/lemon/Makefile.am
Log:
Algorithms by szakall
Modified: hugo/trunk/lemon/Makefile.am
==============================================================================
--- hugo/trunk/lemon/Makefile.am (original)
+++ hugo/trunk/lemon/Makefile.am Fri Jan 27 09:17:25 2006
@@ -30,10 +30,12 @@
counter.h \
dijkstra.h \
dimacs.h \
+ dag_shortest_path.h \
edge_set.h \
error.h \
fib_heap.h \
floyd_warshall.h \
+ fredman_tarjan.h \
full_graph.h \
grid_graph.h \
graph_adaptor.h \
@@ -59,6 +61,7 @@
suurballe.h \
preflow.h \
path.h \
+ prim.h \
radix_heap.h \
radix_sort.h \
smart_graph.h \
Added: hugo/trunk/lemon/dag_shortest_path.h
==============================================================================
--- (empty file)
+++ hugo/trunk/lemon/dag_shortest_path.h Fri Jan 27 09:17:25 2006
@@ -0,0 +1,1082 @@
+/* -*- C++ -*-
+ * lemon/dag_shortest_path.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_DAG_SHORTEST_PATH_H
+#define LEMON_DAG_SHORTEST_PATH_H
+
+///\ingroup flowalgs
+/// \file
+/// \brief DagShortestPath algorithm.
+///
+
+#include <lemon/list_graph.h>
+#include <lemon/invalid.h>
+#include <lemon/error.h>
+#include <lemon/maps.h>
+#include <lemon/topology.h>
+
+#include <limits>
+
+namespace lemon {
+
+ /// \brief Default OperationTraits for the DagShortestPath algorithm class.
+ ///
+ /// It defines all computational operations and constants which are
+ /// used in the dag shortest path 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<Value>::has_infinity>
+ struct DagShortestPathDefaultOperationTraits {
+ /// \brief Gives back the zero value of the type.
+ static Value zero() {
+ return static_cast<Value>(0);
+ }
+ /// \brief Gives back the positive infinity value of the type.
+ static Value infinity() {
+ return std::numeric_limits<Value>::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 <typename Value>
+ struct DagShortestPathDefaultOperationTraits<Value, false> {
+ static Value zero() {
+ return static_cast<Value>(0);
+ }
+ static Value infinity() {
+ return std::numeric_limits<Value>::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 DagShortestPath class.
+ ///
+ /// Default traits class of DagShortestPath class.
+ /// \param _Graph Graph type.
+ /// \param _LegthMap Type of length map.
+ template<class _Graph, class _LengthMap>
+ struct DagShortestPathDefaultTraits {
+ /// 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 dag shortest path algorithm.
+ ///
+ /// It defines the infinity type on the given Value type
+ /// and the used operation.
+ /// \see DagShortestPathDefaultOperationTraits
+ typedef DagShortestPathDefaultOperationTraits<Value> 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<typename _Graph::Edge> PredMap;
+
+ /// \brief Instantiates a PredMap.
+ ///
+ /// This function instantiates a \ref PredMap.
+ /// \param G is the graph, to which we would like to define the PredMap.
+ /// \todo The graph alone may be insufficient for the initialization
+ 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<typename _LengthMap::Value>
+ DistMap;
+
+ /// \brief Instantiates a DistMap.
+ ///
+ /// This function instantiates a \ref DistMap.
+ /// \param G is the graph, to which we would like to define the
+ /// \ref DistMap
+ static DistMap *createDistMap(const _Graph& graph) {
+ return new DistMap(graph);
+ }
+
+ };
+
+ /// \brief Inverse OperationTraits for the DagShortestPath algorithm class.
+ ///
+ /// It defines all computational operations and constants which are
+ /// used in the dag shortest path algorithm. It is the inverse of
+ /// \ref DagShortestPathDefaultOperationTraits, so it can be used to
+ /// calculate the longest path. The default implementation
+ /// is based on the numeric_limits class. If the numeric type does not
+ /// have infinity value then the minimum value is used as extremal
+ /// infinity value.
+ template <
+ typename Value,
+ bool has_infinity = std::numeric_limits<Value>::has_infinity>
+ struct DagLongestPathOperationTraits {
+ /// \brief Gives back the zero value of the type.
+ static Value zero() {
+ return static_cast<Value>(0);
+ }
+ /// \brief Gives back the negative infinity value of the type.
+ static Value infinity() {
+ return -(std::numeric_limits<Value>::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 <typename Value>
+ struct DagLongestPathOperationTraits<Value, false> {
+ static Value zero() {
+ return static_cast<Value>(0);
+ }
+ static Value infinity() {
+ return std::numeric_limits<Value>::min();
+ }
+ 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 Inverse traits class of DagShortestPath class.
+ ///
+ /// Inverse traits class of DagShortestPath class.
+ /// \param _Graph Graph type.
+ /// \param _LegthMap Type of length map.
+ template<class _Graph, class _LengthMap>
+ struct DagLongestPathTraits {
+ /// 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 Inverse operation traits for dag shortest path algorithm.
+ ///
+ /// It defines the infinity type on the given Value type
+ /// and the used operation.
+ /// \see DagLongestPathOperationTraits
+ typedef DagLongestPathOperationTraits<Value> OperationTraits;
+
+ /// \brief The type of the map that stores the last edges of the
+ /// longest paths.
+ ///
+ /// The type of the map that stores the last
+ /// edges of the longest paths.
+ /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+ ///
+ typedef typename Graph::template NodeMap<typename _Graph::Edge> PredMap;
+
+ /// \brief Instantiates a PredMap.
+ ///
+ /// This function instantiates a \ref PredMap.
+ /// \param G is the graph, to which we would like to define the PredMap.
+ /// \todo The graph alone may be insufficient for the initialization
+ 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<typename _LengthMap::Value>
+ DistMap;
+
+ /// \brief Instantiates a DistMap.
+ ///
+ /// This function instantiates a \ref DistMap.
+ /// \param G is the graph, to which we would like to define the
+ /// \ref DistMap
+ static DistMap *createDistMap(const _Graph& graph) {
+ return new DistMap(graph);
+ }
+
+ };
+
+
+ /// \brief %DagShortestPath algorithm class.
+ ///
+ /// \ingroup flowalgs
+ /// This class provides an efficient implementation of a Dag sortest path
+ /// searching 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 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
+ /// DagShortestPath, it is only passed to \ref DagShortestPathDefaultTraits.
+ /// \param _LengthMap This read-only EdgeMap determines the lengths of the
+ /// edges. The default map type is \ref concept::StaticGraph::EdgeMap
+ /// "Graph::EdgeMap<int>". The value of _LengthMap is not used directly
+ /// by DagShortestPath, it is only passed to \ref DagShortestPathDefaultTraits.
+ /// \param _Traits Traits class to set various data types used by the
+ /// algorithm. The default traits class is \ref DagShortestPathDefaultTraits
+ /// "DagShortestPathDefaultTraits<_Graph,_LengthMap>". See \ref
+ /// DagShortestPathDefaultTraits for the documentation of a DagShortestPath traits
+ /// class.
+ ///
+ /// \author Balazs Attila Mihaly (based on Balazs Dezso's work)
+
+#ifdef DOXYGEN
+ template <typename _Graph, typename _LengthMap, typename _Traits>
+#else
+ template <typename _Graph=ListGraph,
+ typename _LengthMap=typename _Graph::template EdgeMap<int>,
+ typename _Traits=DagShortestPathDefaultTraits<_Graph,_LengthMap> >
+#endif
+ class DagShortestPath {
+ 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::DagShortestPath::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::EdgeIt EdgeIt;
+ 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;
+ /// \brief The Node weight map.
+ typedef typename Graph::NodeMap<Value> WeightMap;
+ 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;
+ ///Process step counter
+ unsigned int _process_step;
+
+ std::vector<Node> _node_order;
+
+ /// 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);
+ }
+ }
+
+ public :
+
+ typedef DagShortestPath Create;
+
+ /// \name Named template parameters
+
+ ///@{
+
+ template <class T>
+ 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 <class T>
+ struct DefPredMap {
+ typedef DagShortestPath< Graph, LengthMap, DefPredMapTraits<T> > Create;
+ };
+
+ template <class T>
+ 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 <class T>
+ struct DefDistMap
+ : public DagShortestPath< Graph, LengthMap, DefDistMapTraits<T> > {
+ typedef DagShortestPath< Graph, LengthMap, DefDistMapTraits<T> > Create;
+ };
+
+ template <class T>
+ 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 <class T>
+ struct DefOperationTraits
+ : public DagShortestPath< Graph, LengthMap, DefOperationTraitsTraits<T> > {
+ typedef DagShortestPath< Graph, LengthMap, DefOperationTraitsTraits<T> >
+ Create;
+ };
+
+ ///@}
+
+ protected:
+
+ DagShortestPath() {}
+
+ public:
+
+ /// \brief Constructor.
+ ///
+ /// \param _graph the graph the algorithm will run on.
+ /// \param _length the length map used by the algorithm.
+ DagShortestPath(const Graph& _graph, const LengthMap& _length) :
+ graph(&_graph), length(&_length),
+ _pred(0), local_pred(false),
+ _dist(0), local_dist(false){}
+
+ /// \brief Constructor with node weight map.
+ ///
+ /// \param _graph the graph the algorithm will run on.
+ /// \param _length the length map used by the algorithm.
+ /// The NodeMap _length will be used as the weight map.
+ /// Each edge will have the weight of its target node.
+ DagShortestPath(const Graph& _graph, const WeightMap& _length) :
+ graph(&_graph),
+ _pred(0), local_pred(false),
+ _dist(0), local_dist(false){
+ length=new LengthMap(_graph);
+ _dist=new DistMap(_graph);
+ for(EdgeIt eit(_graph);eit!=INVALID;++eit)
+ (const_cast<LengthMap*>(length))->set(eit,_length[_graph.target(eit)]);
+ }
+
+ ///Destructor.
+ ~DagShortestPath() {
+ if(local_pred) delete _pred;
+ if(local_dist) delete _dist;
+ }
+
+ /// \brief Sets the length map.
+ ///
+ /// Sets the length map.
+ /// \return \c (*this)
+ DagShortestPath &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)
+ DagShortestPath &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)
+ DagShortestPath &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.
+ /// Some functions have an alternative form (\ref checkedInit(...),
+ /// \ref checkedRun(...)) which also verifies if the graph given in the
+ /// constructor is a dag.
+
+ ///@{
+
+ /// \brief Initializes the internal data structures.
+ ///
+ /// Initializes the internal data structures.
+ void init(const Value value = OperationTraits::infinity()) {
+ typedef typename Graph::template NodeMap<int> NodeOrderMap;
+ _process_step=0;
+ NodeOrderMap node_order(*graph);
+ topologicalSort(*graph,node_order);
+ _node_order.resize(countNodes(*graph),INVALID);
+ create_maps();
+ for (NodeIt it(*graph); it != INVALID; ++it) {
+ _node_order[node_order[it]]=it;
+ _pred->set(it, INVALID);
+ _dist->set(it, value);
+ }
+ }
+
+ /// \brief Initializes the internal data structures
+ /// with a given topological sort (NodeMap).
+ ///
+ /// Initializes the internal data structures
+ /// with a given topological sort (NodeMap).
+ void init(const typename Graph::template NodeMap<int>& node_order,
+ const Value value = OperationTraits::infinity()) {
+ _process_step=0;
+ _node_order.resize(countNodes(*graph),INVALID);
+ create_maps();
+ for (NodeIt it(*graph); it != INVALID; ++it) {
+ _node_order[node_order[it]]=it;
+ _pred->set(it, INVALID);
+ _dist->set(it, value);
+ }
+ }
+
+ /// \brief Initializes the internal data structures
+ /// with a given topological sort (std::vector).
+ ///
+ /// Initializes the internal data structures
+ /// with a given topological sort (std::vector).
+ void init(const std::vector<Node>& node_order,
+ const Value value = OperationTraits::infinity()) {
+ _process_step=0;
+ _node_order=node_order;
+ create_maps();
+ for (NodeIt it(*graph); it != INVALID; ++it) {
+ _pred->set(it, INVALID);
+ _dist->set(it, value);
+ }
+ }
+
+ /// \brief Initializes the internal data structures. It also checks if the graph is dag.
+ ///
+ /// Initializes the internal data structures. It also checks if the graph is dag.
+ /// \return true if the graph (given in the constructor) is dag, false otherwise.
+ bool checkedInit(const Value value = OperationTraits::infinity()) {
+ typedef typename Graph::template NodeMap<int> NodeOrderMap;
+ NodeOrderMap node_order(*graph);
+ if(!checkedTopologicalSort(*graph,node_order))return false;
+ init(node_order,value);
+ return true;
+ }
+
+ /// \brief Initializes the internal data structures with a given
+ /// topological sort (NodeMap). It also checks if the graph is dag.
+ ///
+ /// Initializes the internal data structures with a given
+ /// topological sort (NodeMap). It also checks if the graph is dag.
+ /// \return true if the graph (given in the constructor) is dag, false otherwise.
+ bool checkedInit(const typename Graph::template NodeMap<int>& node_order,
+ const Value value = OperationTraits::infinity()) {
+ for(NodeIt it(*graph);it!=INVALID;++it){
+ for(OutEdgeIt oeit(*graph,it);oeit!=INVALID;++oeit){
+ if(node_order[graph->target(oeit)]<node_order[it])return false;
+ }
+ }
+ init(node_order,value);
+ return true;
+ }
+
+ /// \brief Initializes the internal data structures with a given
+ /// topological sort (std::vector). It also checks if the graph is dag.
+ ///
+ /// Initializes the internal data structures with a given
+ /// topological sort (std::vector). It also checks if the graph is dag.
+ /// \return true if the graph (given in the constructor) is dag, false otherwise.
+ bool checkedInit(const std::vector<Node>& node_order,
+ const Value value = OperationTraits::infinity()) {
+ typedef typename Graph::template NodeMap<bool> BoolNodeMap;
+ BoolNodeMap _processed(*graph,false);
+ for(unsigned int i=0;i<_node_order.size();++i){
+ _processed[node_order[i]]=true;
+ for(OutEdgeIt oeit(*graph,node_order[i]);oeit!=INVALID;++oeit){
+ if(_processed[graph->target(oeit)])return false;
+ }
+ }
+ init(node_order,value);
+ return 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()) {
+ if((*_dist)[source] != dst){
+ _dist->set(source, dst);
+ }
+ }
+
+ /// \brief Executes one step from the dag shortest path algorithm.
+ ///
+ /// If the algoritm calculated the distances in the previous step
+ /// 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.
+ ///\pre the queue is not empty
+ ///\return the currently processed node
+ Node processNextNode() {
+ if(reached(_node_order[_process_step])){
+ for (OutEdgeIt it(*graph, _node_order[_process_step]); it != INVALID; ++it) {
+ Node target = graph->target(it);
+ Value relaxed =
+ OperationTraits::plus((*_dist)[_node_order[_process_step]], (*length)[it]);
+ if (OperationTraits::less(relaxed, (*_dist)[target])) {
+ _pred->set(target, it);
+ _dist->set(target, relaxed);
+ }
+ }
+ }
+ ++_process_step;
+ return _node_order[_process_step-1];
+ }
+
+ ///\brief Returns \c false if there are nodes
+ ///to be processed in the queue
+ ///
+ ///Returns \c false if there are nodes
+ ///to be processed in the queue
+ bool emptyQueue() { return _node_order.size()-1==_process_step; }
+
+ ///\brief Returns the number of the nodes to be processed.
+ ///
+ ///Returns the number of the nodes to be processed in the queue.
+ int queueSize() { return _node_order.size()-1-_process_step; }
+
+ /// \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 %DagShortestPath 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() {
+ while(!emptyQueue()) {
+ processNextNode();
+ }
+ }
+
+ /// \brief Runs %DagShortestPath algorithm from node \c s.
+ ///
+ /// This method runs the %DagShortestPath 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 %DagShortestPath algorithm from node \c s.
+ /// It also checks if the graph is a dag.
+ ///
+ /// This method runs the %DagShortestPath 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.
+ /// The algorithm checks if the graph given int the constructor is a dag.
+ bool checkedRun(Node s) {
+ if(!checkedInit())return false;
+ addSource(s);
+ start();
+ return true;
+ }
+
+ ///@}
+
+ /// \name Query Functions
+ /// The result of the %DagShortestPath 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 <typename Path>
+ 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 DagShortestPath function.
+ ///
+ /// Default traits class of DagShortestPath function.
+ /// \param _Graph Graph type.
+ /// \param _LengthMap Type of length map.
+ template <typename _Graph, typename _LengthMap>
+ struct DagShortestPathWizardDefaultTraits {
+ /// \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 dag shortest path algorithm.
+ ///
+ /// It defines the infinity type on the given Value type
+ /// and the used operation.
+ /// \see DagShortestPathDefaultOperationTraits
+ typedef DagShortestPathDefaultOperationTraits<Value> 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 <typename _Graph::Node,typename _Graph::Edge> 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<typename Graph::Node, Value> 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 DagShortestPathWizard
+ ///
+ /// To make it easier to use DagShortestPath algorithm
+ /// we have created a wizard class.
+ /// This \ref DagShortestPathWizard class needs default traits,
+ /// as well as the \ref DagShortestPath class.
+ /// The \ref DagShortestPathWizardBase is a class to be the default traits of the
+ /// \ref DagShortestPathWizard class.
+ /// \todo More named parameters are required...
+ template<class _Graph,class _LengthMap>
+ class DagShortestPathWizardBase
+ : public DagShortestPathWizardDefaultTraits<_Graph,_LengthMap> {
+
+ typedef DagShortestPathWizardDefaultTraits<_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).
+ DagShortestPathWizardBase() : _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
+ DagShortestPathWizardBase(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 DagShortestPath algorithm easier
+
+ /// This class is created to make it easier to use DagShortestPath algorithm.
+ /// It uses the functions and features of the plain \ref DagShortestPath,
+ /// 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 DagShortestPath
+ /// the new class with the modified type comes from
+ /// the original class by using the ::
+ /// operator. In the case of \ref DagShortestPathWizard 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 DagShortestPath class, and calls the \ref
+ /// DagShortestPath::run() method of it.
+ template<class _Traits>
+ class DagShortestPathWizard : 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.
+ DagShortestPathWizard() : _Traits() {}
+
+ /// \brief Constructor that requires parameters.
+ ///
+ /// Constructor that requires parameters.
+ /// These parameters will be the default values for the traits class.
+ DagShortestPathWizard(const Graph& graph, const LengthMap& length,
+ Node source = INVALID)
+ : _Traits(graph, length, source) {}
+
+ /// \brief Copy constructor
+ DagShortestPathWizard(const _Traits &b) : _Traits(b) {}
+
+ ~DagShortestPathWizard() {}
+
+ /// \brief Runs DagShortestPath algorithm from a given node.
+ ///
+ /// Runs DagShortestPath algorithm from a given node.
+ /// The node can be given by the \ref source function.
+ void run() {
+ if(Base::_source == INVALID) throw UninitializedParameter();
+ DagShortestPath<Graph,LengthMap,_Traits>
+ 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 DagShortestPath algorithm from the given node.
+ ///
+ /// Runs DagShortestPath algorithm from the given node.
+ /// \param s is the given source.
+ void run(Node source) {
+ Base::_source = source;
+ run();
+ }
+
+ template<class T>
+ 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<class T>
+ DagShortestPathWizard<DefPredMapBase<T> > predMap(const T &t)
+ {
+ Base::_pred=(void *)&t;
+ return DagShortestPathWizard<DefPredMapBase<T> >(*this);
+ }
+
+ template<class T>
+ 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<class T>
+ DagShortestPathWizard<DefDistMapBase<T> > distMap(const T &t) {
+ Base::_dist=(void *)&t;
+ return DagShortestPathWizard<DefDistMapBase<T> >(*this);
+ }
+
+ template<class T>
+ 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<class T>
+ DagShortestPathWizard<DefOperationTraitsBase<T> > distMap() {
+ return DagShortestPathWizard<DefDistMapBase<T> >(*this);
+ }
+
+ /// \brief Sets the source node, from which the DagShortestPath algorithm runs.
+ ///
+ /// Sets the source node, from which the DagShortestPath algorithm runs.
+ /// \param s is the source node.
+ DagShortestPathWizard<_Traits>& source(Node source) {
+ Base::_source = source;
+ return *this;
+ }
+
+ };
+
+ /// \brief Function type interface for DagShortestPath algorithm.
+ ///
+ /// \ingroup flowalgs
+ /// Function type interface for DagShortestPath algorithm.
+ ///
+ /// This function also has several \ref named-templ-func-param
+ /// "named parameters", they are declared as the members of class
+ /// \ref DagShortestPathWizard.
+ /// The following
+ /// example shows how to use these parameters.
+ /// \code
+ /// dagShortestPath(g,length,source).predMap(preds).run();
+ /// \endcode
+ /// \warning Don't forget to put the \ref DagShortestPathWizard::run() "run()"
+ /// to the end of the parameter list.
+ /// \sa DagShortestPathWizard
+ /// \sa DagShortestPath
+ template<class _Graph, class _LengthMap>
+ DagShortestPathWizard<DagShortestPathWizardBase<_Graph,_LengthMap> >
+ dagShortestPath(const _Graph& graph,
+ const _LengthMap& length,
+ typename _Graph::Node source = INVALID) {
+ return DagShortestPathWizard<DagShortestPathWizardBase<_Graph,_LengthMap> >
+ (graph, length, source);
+ }
+
+} //END OF NAMESPACE LEMON
+
+#endif
+
Added: hugo/trunk/lemon/fredman_tarjan.h
==============================================================================
--- (empty file)
+++ hugo/trunk/lemon/fredman_tarjan.h Fri Jan 27 09:17:25 2006
@@ -0,0 +1,509 @@
+/* -*- C++ -*-
+ * lemon/fredman_tarjan.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_FREDMAN_TARJAN_H
+#define LEMON_FREDMAN_TARJAN_H
+
+///\ingroup spantree
+///\file
+///\brief FredmanTarjan algorithm to compute minimum spanning forest.
+
+#include <limits>
+#include <vector>
+
+#include <lemon/list_graph.h>
+#include <lemon/smart_graph.h>
+#include <lemon/fib_heap.h>
+#include <lemon/radix_sort.h>
+#include <lemon/invalid.h>
+#include <lemon/error.h>
+#include <lemon/maps.h>
+#include <lemon/traits.h>
+#include <lemon/graph_utils.h>
+
+#include <lemon/concept/ugraph.h>
+
+namespace lemon {
+
+ ///Default traits class of FredmanTarjan class.
+
+ ///Default traits class of FredmanTarjan class.
+ ///\param GR Graph type.
+ ///\param LM Type of cost map.
+ template<class GR, class LM>
+ struct FredmanTarjanDefaultTraits{
+ ///The graph type the algorithm runs on.
+ typedef GR UGraph;
+ ///The type of the map that stores the edge costs.
+
+ ///The type of the map that stores the edge costs.
+ ///It must meet the \ref concept::ReadMap "ReadMap" concept.
+ typedef LM CostMap;
+ //The type of the cost of the edges.
+ typedef typename LM::Value Value;
+ ///The type of the map that stores whether an edge is in the
+ ///spanning tree or not.
+
+ ///The type of the map that stores whether an edge is in the
+ ///spanning tree or not.
+ ///It must meet the \ref concept::ReadWriteMap "ReadWriteMap" concept.
+ ///By default it is a BoolEdgeMap.
+ typedef typename UGraph::template UEdgeMap<bool> TreeMap;
+ ///Instantiates a TreeMap.
+
+ ///This function instantiates a \ref TreeMap.
+ ///\param g is the graph, to which
+ ///we would like to define the \ref TreeMap
+ static TreeMap *createTreeMap(const GR &_graph){
+ return new TreeMap(_graph);
+ }
+ };
+
+ ///%FredmanTarjan algorithm class to find a minimum spanning tree.
+
+ /// \ingroup spantree
+ ///This class provides an efficient implementation of %FredmanTarjan algorithm
+ ///whitch is sometimes a bit quicker than the Prim algorithm on larger graphs.
+ ///Due to the structure of the algorithm, it has less controll functions than
+ ///Prim.
+ ///
+ ///The running time is O(e*B(e,n)) where e is the number of edges, n is the
+ ///number of nodes in the graph and B(e,n) is min { i | log^(i) n <= e/n}
+ ///( log^(i+1) n = log(log^(i)) n )
+ ///
+ ///The edge costs are passed to the algorithm using a
+ ///\ref concept::ReadMap "ReadMap",
+ ///so it is easy to change it to any kind of cost.
+ ///
+ ///The type of the cost is determined by the
+ ///\ref concept::ReadMap::Value "Value" of the cost map.
+ ///
+ ///\param GR The graph type the algorithm runs on. The default value
+ ///is \ref ListUGraph. The value of GR is not used directly by
+ ///FredmanTarjan, it is only passed to \ref FredmanTarjanDefaultTraits.
+ ///
+ ///\param LM This read-only UEdgeMap determines the costs of the
+ ///edges. It is read once for each edge, so the map may involve in
+ ///relatively time consuming process to compute the edge cost if
+ ///it is necessary. The default map type is \ref
+ ///concept::UGraph::UEdgeMap "UGraph::UEdgeMap<int>". The value
+ ///of LM is not used directly by FredmanTarjan, it is only passed to \ref
+ ///FredmanTarjanDefaultTraits.
+ ///
+ ///\param TR Traits class to set
+ ///various data types used by the algorithm. The default traits
+ ///class is \ref FredmanTarjanDefaultTraits
+ ///"FredmanTarjanDefaultTraits<GR,LM>". See \ref
+ ///FredmanTarjanDefaultTraits for the documentation of a FredmanTarjan traits
+ ///class.
+ ///
+ ///\author Balazs Attila Mihaly
+
+#ifdef DOXYGEN
+ template <typename GR,
+ typename LM,
+ typename TR>
+#else
+ template <typename GR=ListUGraph,
+ typename LM=typename GR::template UEdgeMap<int>,
+ typename TR=FredmanTarjanDefaultTraits<GR,LM> >
+#endif
+ class FredmanTarjan {
+ 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::FredmanTarjan::UninitializedParameter";
+ }
+ };
+
+ typedef GR Graph;
+ typedef TR Traits;
+ ///The type of the underlying graph.
+ typedef typename TR::UGraph UGraph;
+ ///\e
+ typedef typename UGraph::Node Node;
+ ///\e
+ typedef typename UGraph::NodeIt NodeIt;
+ ///\e
+ typedef typename UGraph::UEdge UEdge;
+ ///\e
+ typedef typename UGraph::UEdgeIt UEdgeIt;
+ ///\e
+ typedef typename UGraph::IncEdgeIt IncEdgeIt;
+
+ ///The type of the cost of the edges.
+ typedef typename TR::CostMap::Value Value;
+ ///The type of the map that stores the edge costs.
+ typedef typename TR::CostMap CostMap;
+ ///Edges of the spanning tree.
+ typedef typename TR::TreeMap TreeMap;
+ private:
+ ///Pointer to the underlying graph.
+ const UGraph *graph;
+ ///Pointer to the cost map
+ const CostMap *cost;
+ ///Pointer to the map of tree edges.
+ TreeMap *_tree;
+ ///Indicates if \ref _tree is locally allocated (\c true) or not.
+ bool local_tree;
+
+ ///Creates the maps if necessary.
+
+ void create_maps(){
+ if(!_tree){
+ local_tree=true;
+ _tree=Traits::createTreeMap(*graph);
+ }
+ }
+
+ public :
+
+ typedef FredmanTarjan Create;
+
+ ///\name Named template parameters
+
+ ///@{
+
+ template <class TM>
+ struct DefTreeMapTraits : public Traits {
+ typedef TM TreeMap;
+ static TreeMap *createTreeMap(const UGraph &) {
+ throw UninitializedParameter();
+ }
+ };
+ ///\ref named-templ-param "Named parameter" for setting TreeMap
+
+ ///\ref named-templ-param "Named parameter" for setting TreeMap
+ ///
+ template <class TM>
+ struct DefTreeMap
+ : public FredmanTarjan< UGraph, CostMap, DefTreeMapTraits<TM> > {
+ typedef FredmanTarjan< UGraph, CostMap, DefTreeMapTraits<TM> > Create;
+ };
+
+ ///@}
+
+
+ protected:
+
+ FredmanTarjan() {}
+
+ private:
+
+ template<class SrcGraph,class OrigMap,class Heap,class ProcessedMap,class PredMap>
+ void processNextTree(const SrcGraph& graph,const OrigMap& orig,Heap &heap,
+ ProcessedMap& processed,PredMap& pred,int& tree_counter,const int limit){
+ std::vector<typename SrcGraph::Node> tree_nodes;
+ int tree_index=tree_counter;
+ bool stop=false;
+ while(!heap.empty() && !stop){
+ typename SrcGraph::Node v=heap.top();
+ heap.pop();
+ if(processed[v]!=-1){
+ heap.state(v,Heap::PRE_HEAP);
+ tree_index=processed[v];
+ _tree->set(orig[pred[v]],true);
+ stop=true;
+ break;
+ }
+ tree_nodes.push_back(v);
+ for(typename SrcGraph::IncEdgeIt e(graph,v);e!=INVALID;++e){
+ typename SrcGraph::Node w=graph.oppositeNode(v,e);
+ switch(heap.state(w)){
+ case Heap::PRE_HEAP:
+ if(heap.size()>=limit){
+ stop=true;
+ }
+ else{
+ heap.push(w,(*cost)[orig[e]]);
+ pred.set(w,e);
+ }
+ break;
+ case Heap::IN_HEAP:
+ if ((*cost)[orig[e]]<heap[w]){
+ heap.decrease(w,(*cost)[orig[e]]);
+ pred.set(w,e);
+ }
+ break;
+ case Heap::POST_HEAP:
+ break;
+ }
+ }
+ }
+ for(int i=1;i<(int)tree_nodes.size();++i){
+ _tree->set(orig[pred[tree_nodes[i]]],true);
+ processed.set(tree_nodes[i],tree_index);
+ heap.state(tree_nodes[i], Heap::PRE_HEAP);
+ }
+ processed.set(tree_nodes[0],tree_index);
+ heap.state(tree_nodes[0],Heap::PRE_HEAP);
+ while (!heap.empty()) {
+ typename SrcGraph::Node v=heap.top();
+ heap.pop();
+ heap.state(v,Heap::PRE_HEAP);
+ }
+ if(!stop)++tree_counter;
+ }
+
+ template<class SrcGraph,class OrigMap,class ProcessedMap>
+ void createTrees(const SrcGraph& graph,const OrigMap& orig, ProcessedMap& processed,
+ int edgenum,int& tree_counter){
+ typedef typename SrcGraph::Node Node;
+ typedef typename SrcGraph::UEdge UEdge;
+ typedef typename SrcGraph::NodeIt NodeIt;
+ typedef typename SrcGraph::template NodeMap<int> HeapCrossRef;
+ typedef typename SrcGraph::template NodeMap<UEdge> PredMap;
+ HeapCrossRef crossref(graph,-1);
+ FibHeap<Node,Value,HeapCrossRef> heap(crossref);
+ PredMap pred(graph,INVALID);
+ int rate=2*edgenum/countNodes(graph);
+ int limit=(rate>std::numeric_limits<int>::digits)?std::numeric_limits<int>::max():(1<<rate);
+ for(NodeIt i(graph);i!=INVALID;++i){
+ if(processed[i]==-1){
+ heap.push(i, Value());
+ processNextTree(graph,orig,heap,processed,pred,tree_counter,limit);
+ }
+ }
+ }
+
+ template<class SrcGraph,class DestGraph,class SrcOrigMap,class DestOrigMap,class ProcessedMap>
+ void collect(const SrcGraph& srcgraph,const SrcOrigMap& srcorig,DestGraph& destgraph,
+ DestOrigMap& destorig,const ProcessedMap& processed,const int tree_counter){
+ typedef typename SrcGraph::Node Node;
+ typedef typename DestGraph::Node DNode;
+ typedef typename SrcGraph::UEdge UEdge;
+ typedef typename DestGraph::UEdge DUEdge;
+ typedef typename SrcGraph::Edge Edge;
+ typedef typename SrcGraph::EdgeIt EdgeIt;
+ std::vector<Edge> edges;
+ std::vector<DNode> nodes(tree_counter, INVALID);
+ for(EdgeIt i(srcgraph);i!=INVALID;++i){
+ if(processed[srcgraph.source(i)]<processed[srcgraph.target(i)]){
+ edges.push_back(i);
+ if(nodes[processed[srcgraph.source(i)]]==INVALID) {
+ nodes[processed[srcgraph.source(i)]]=destgraph.addNode();
+ }
+ if(nodes[processed[srcgraph.target(i)]]==INVALID) {
+ nodes[processed[srcgraph.target(i)]]=destgraph.addNode();
+ }
+ }
+ }
+
+ radixSort(edges.begin(),edges.end(),mapFunctor(composeMap(processed,sourceMap(srcgraph))));
+ counterSort(edges.begin(),edges.end(),mapFunctor(composeMap(processed,targetMap(srcgraph))));
+ for(int i=0;i!=(int)edges.size();++i){
+ int srcproc=processed[srcgraph.source(edges[i])];
+ int trgproc=processed[srcgraph.target(edges[i])];
+ Value minval=(*cost)[srcorig[edges[i]]];
+ UEdge minpos=edges[i];
+ while (i+1!=(int)edges.size() && srcproc==processed[srcgraph.source(edges[i+1])] &&
+ trgproc==processed[srcgraph.target(edges[i+1])]) {
+ if (minval>(*cost)[srcorig[edges[i+1]]]) {
+ minval=(*cost)[srcorig[edges[i+1]]];
+ minpos=edges[i+1];
+ }
+ ++i;
+ }
+ destorig[destgraph.addEdge(nodes[srcproc],nodes[trgproc])]=srcorig[minpos];
+ }
+ }
+
+ template<class SrcGraph,class OrigMap>
+ void phase(const SrcGraph& graph,const OrigMap& orig,int edgenum){
+ int tree_counter = 0;
+ typename SrcGraph::template NodeMap<int> processed(graph,-1);
+ SmartUGraph destgraph;
+ SmartUGraph::UEdgeMap<typename OrigMap::Value> destorig(destgraph);
+ createTrees(graph,orig,processed,edgenum,tree_counter);
+ collect(graph,orig,destgraph,destorig,processed,tree_counter);
+ if (countNodes(destgraph)>1) {
+ phase(destgraph,destorig,edgenum);
+ }
+ }
+
+ public:
+
+ ///Constructor.
+
+ ///\param _graph the graph the algorithm will run on.
+ ///\param _cost the cost map used by the algorithm.
+ FredmanTarjan(const UGraph& _graph, const CostMap& _cost) :
+ graph(&_graph), cost(&_cost),
+ _tree(0), local_tree(false)
+ {
+ checkConcept<concept::UGraph, UGraph>();
+ }
+
+ ///Destructor.
+ ~FredmanTarjan(){
+ if(local_tree) delete _tree;
+ }
+
+ ///Sets the cost map.
+
+ ///Sets the cost map.
+ ///\return <tt> (*this) </tt>
+ FredmanTarjan &costMap(const CostMap &m){
+ cost = &m;
+ return *this;
+ }
+
+ ///Sets the map storing the tree edges.
+
+ ///Sets the map storing the tree 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.
+ ///By default this is a BoolEdgeMap.
+ ///\return <tt> (*this) </tt>
+ FredmanTarjan &treeMap(TreeMap &m){
+ if(local_tree) {
+ delete _tree;
+ local_tree=false;
+ }
+ _tree = &m;
+ return *this;
+ }
+
+ public:
+ ///\name Execution control
+ ///The simplest way to execute the algorithm is to use
+ ///one of the member functions called \c run(...).
+
+ ///@{
+
+ ///Initializes the internal data structures.
+
+ ///Initializes the internal data structures.
+ ///
+ void init(){
+ create_maps();
+ for(typename Graph::UEdgeIt i(*graph);i!=INVALID;++i){
+ _tree->set(i,false);
+ }
+ }
+
+ ///Executes the algorithm.
+
+ ///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 %FredmanTarjan algorithm from the node(s)
+ ///in order to compute the
+ ///minimum spanning tree.
+ void start(){
+ phase(*graph,identityMap<UEdge>(),countEdges(*graph));
+ }
+
+ ///Runs %FredmanTarjan algorithm.
+
+ ///This method runs the %FredmanTarjan algorithm
+ ///in order to compute the minimum spanning forest.
+ ///
+ ///\note ft.run() is just a shortcut of the following code.
+ ///\code
+ /// ft.init();
+ /// ft.start();
+ ///\endcode
+ void run() {
+ init();
+ start();
+ }
+
+ ///@}
+
+ ///\name Query Functions
+ ///The result of the %FredmanTarjan algorithm can be obtained using these
+ ///functions.\n
+ ///Before the use of these functions,
+ ///either run() or start() must be called.
+
+ ///@{
+
+ ///Returns a reference to the tree edges map.
+
+ ///Returns a reference to the TreeEdgeMap of the edges of the
+ ///minimum spanning tree. The value of the map is \c true only if the
+ ///edge is in the minimum spanning tree.
+ ///
+ ///\pre \ref run() or \ref start() must be called before using this
+ ///function.
+ const TreeMap &treeMap() const { return *_tree;}
+
+ ///Sets the tree edges map.
+
+ ///Sets the TreeMap of the edges of the minimum spanning tree.
+ ///The map values belonging to the edges of the minimum
+ ///spanning tree are set to \param tree_edge_value or \c true by default
+ ///while the edge values not belonging to the minimum spanning tree are
+ ///set to
+ ///\param tree_default_value or \c false by default.
+ ///
+ ///\pre \ref run() or \ref start() must be called before using this
+ ///function.
+
+ template<class TreeMap>
+ void treeEdges(
+ TreeMap& tree,
+ const typename TreeMap::Value& tree_edge_value=true,
+ const typename TreeMap::Value& tree_default_value=false) const {
+ for(typename UGraph::UEdgeIt i(*graph);i!=INVALID;++i){
+ (*_tree)[i]?tree.set(i,tree_edge_value):tree.set(i,tree_default_value);
+ }
+ }
+
+ ///\brief Checks if an edge is in the spanning tree or not.
+
+ ///Checks if an edge is in the spanning tree or not.
+ ///\param e is the edge that will be checked
+ ///\return \c true if e is in the spanning tree, \c false otherwise
+ bool tree(UEdge e){
+ return (*_tree)[e];
+ }
+ ///@}
+ };
+
+ /// \ingroup spantree
+ ///
+ /// \brief Function type interface for FredmanTarjan algorithm.
+ ///
+ /// Function type interface for FredmanTarjan algorithm.
+ /// \param graph the UGraph that the algorithm runs on
+ /// \param cost the CostMap of the edges
+ /// \retval tree the EdgeMap that contains whether an edge is in the
+ /// spanning tree or not
+ ///
+ /// \sa Prim
+ template<class Graph,class CostMap,class TreeMap>
+ void fredmanTarjan(const Graph& graph, const CostMap& cost,TreeMap& tree){
+ typename FredmanTarjan<Graph,CostMap>::template DefTreeMap<TreeMap>::
+ Create ft(graph,cost);
+ ft.treeMap(tree);
+ ft.run();
+ };
+
+} //END OF NAMESPACE LEMON
+
+#endif
Added: hugo/trunk/lemon/prim.h
==============================================================================
--- (empty file)
+++ hugo/trunk/lemon/prim.h Fri Jan 27 09:17:25 2006
@@ -0,0 +1,792 @@
+/* -*- C++ -*-
+ * lemon/prim.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_PRIM_H
+#define LEMON_PRIM_H
+
+///\ingroup spantree
+///\file
+///\brief Prim algorithm to compute minimum spanning tree.
+
+#include <lemon/list_graph.h>
+#include <lemon/bin_heap.h>
+#include <lemon/invalid.h>
+#include <lemon/error.h>
+#include <lemon/maps.h>
+#include <lemon/traits.h>
+
+#include <lemon/concept/ugraph.h>
+
+namespace lemon {
+
+ ///Default traits class of Prim class.
+
+ ///Default traits class of Prim class.
+ ///\param GR Graph type.
+ ///\param LM Type of cost map.
+ template<class GR, class LM>
+ struct PrimDefaultTraits{
+ ///The graph type the algorithm runs on.
+ typedef GR UGraph;
+ ///The type of the map that stores the edge costs.
+
+ ///The type of the map that stores the edge costs.
+ ///It must meet the \ref concept::ReadMap "ReadMap" concept.
+ typedef LM CostMap;
+ //The type of the cost of the edges.
+ typedef typename LM::Value Value;
+ /// The cross reference type used by heap.
+
+ /// The cross reference type used by heap.
+ /// Usually it is \c UGraph::NodeMap<int>.
+ typedef typename UGraph::template NodeMap<int> HeapCrossRef;
+ ///Instantiates a HeapCrossRef.
+
+ ///This function instantiates a \ref HeapCrossRef.
+ /// \param G is the graph, to which we would like to define the
+ /// HeapCrossRef.
+ static HeapCrossRef *createHeapCrossRef(const GR &_graph){
+ return new HeapCrossRef(_graph);
+ }
+
+ ///The heap type used by Prim algorithm.
+
+ ///The heap type used by Prim algorithm.
+ ///
+ ///\sa BinHeap
+ ///\sa Prim
+ typedef BinHeap<typename UGraph::Node, typename LM::Value,
+ HeapCrossRef, std::less<Value> > Heap;
+
+ static Heap *createHeap(HeapCrossRef& _ref){
+ return new Heap(_ref);
+ }
+
+ ///\brief The type of the map that stores the last
+ ///edges of the minimum spanning tree.
+ ///
+ ///The type of the map that stores the last
+ ///edges of the minimum spanning tree.
+ ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+ ///
+ typedef typename UGraph::template NodeMap<typename GR::UEdge> PredMap;
+ ///Instantiates a PredMap.
+
+ ///This function instantiates a \ref PredMap.
+ ///\param G is the graph, to which we would like to define the PredMap.
+ static PredMap *createPredMap(const GR &_graph){
+ return new PredMap(_graph);
+ }
+
+ ///The type of the map that stores whether an edge is in the
+ ///spanning tree or not.
+
+ ///The type of the map that stores whether an edge is in the
+ ///spanning tree or not.
+ ///By default it is a NullMap.
+ typedef NullMap<typename UGraph::UEdge,bool> TreeMap;
+ ///Instantiates a TreeMap.
+
+ ///This function instantiates a \ref TreeMap.
+ ///\param g is the graph, to which
+ ///we would like to define the \ref TreeMap
+ static TreeMap *createTreeMap(const GR &){
+ return new TreeMap();
+ }
+
+ ///The type of the map that stores whether a nodes is processed.
+
+ ///The type of the map that stores whether a nodes is processed.
+ ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+ ///By default it is a NodeMap<bool>.
+ typedef NullMap<typename UGraph::Node,bool> ProcessedMap;
+ ///Instantiates a ProcessedMap.
+
+ ///This function instantiates a \ref ProcessedMap.
+ ///\param g is the graph, to which
+ ///we would like to define the \ref ProcessedMap
+#ifdef DOXYGEN
+ static ProcessedMap *createProcessedMap(const GR &_graph)
+#else
+ static ProcessedMap *createProcessedMap(const GR &)
+#endif
+ {
+ return new ProcessedMap();
+ }
+ };
+
+ ///%Prim algorithm class to find a minimum spanning tree.
+
+ /// \ingroup spantree
+ ///This class provides an efficient implementation of %Prim algorithm.
+ ///
+ ///The running time is O(e*log n) where e is the number of edges and
+ ///n is the number of nodes in the graph.
+ ///
+ ///The edge costs are passed to the algorithm using a
+ ///\ref concept::ReadMap "ReadMap",
+ ///so it is easy to change it to any kind of cost.
+ ///
+ ///The type of the cost is determined by the
+ ///\ref concept::ReadMap::Value "Value" of the cost map.
+ ///
+ ///It is also possible to change the underlying priority heap.
+ ///
+ ///\param GR The graph type the algorithm runs on. The default value
+ ///is \ref ListUGraph. The value of GR is not used directly by
+ ///Prim, it is only passed to \ref PrimDefaultTraits.
+ ///
+ ///\param LM This read-only UEdgeMap determines the costs of the
+ ///edges. It is read once for each edge, so the map may involve in
+ ///relatively time consuming process to compute the edge cost if
+ ///it is necessary. The default map type is \ref
+ ///concept::UGraph::UEdgeMap "UGraph::UEdgeMap<int>". The value
+ ///of LM is not used directly by Prim, it is only passed to \ref
+ ///PrimDefaultTraits.
+ ///
+ ///\param TR Traits class to set
+ ///various data types used by the algorithm. The default traits
+ ///class is \ref PrimDefaultTraits
+ ///"PrimDefaultTraits<GR,LM>". See \ref
+ ///PrimDefaultTraits for the documentation of a Prim traits
+ ///class.
+ ///
+ ///\author Balazs Attila Mihaly
+
+#ifdef DOXYGEN
+ template <typename GR,
+ typename LM,
+ typename TR>
+#else
+ template <typename GR=ListUGraph,
+ typename LM=typename GR::template UEdgeMap<int>,
+ typename TR=PrimDefaultTraits<GR,LM> >
+#endif
+ class Prim {
+ 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::Prim::UninitializedParameter";
+ }
+ };
+
+ typedef TR Traits;
+ ///The type of the underlying graph.
+ typedef typename TR::UGraph UGraph;
+ ///\e
+ typedef typename UGraph::Node Node;
+ ///\e
+ typedef typename UGraph::NodeIt NodeIt;
+ ///\e
+ typedef typename UGraph::UEdge UEdge;
+ ///\e
+ typedef typename UGraph::IncEdgeIt IncEdgeIt;
+
+ ///The type of the cost of the edges.
+ typedef typename TR::CostMap::Value Value;
+ ///The type of the map that stores the edge costs.
+ typedef typename TR::CostMap CostMap;
+ ///\brief The type of the map that stores the last
+ ///predecessor edges of the spanning tree.
+ typedef typename TR::PredMap PredMap;
+ ///Edges of the spanning tree.
+ typedef typename TR::TreeMap TreeMap;
+ ///The type of the map indicating if a node is processed.
+ typedef typename TR::ProcessedMap ProcessedMap;
+ ///The cross reference type used for the current heap.
+ typedef typename TR::HeapCrossRef HeapCrossRef;
+ ///The heap type used by the prim algorithm.
+ typedef typename TR::Heap Heap;
+ private:
+ /// Pointer to the underlying graph.
+ const UGraph *graph;
+ /// Pointer to the cost map
+ const CostMap *cost;
+ ///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 tree edges.
+ TreeMap *_tree;
+ ///Indicates if \ref _tree is locally allocated (\c true) or not.
+ bool local_tree;
+ ///Pointer to the map of processed status of the nodes.
+ ProcessedMap *_processed;
+ ///Indicates if \ref _processed is locally allocated (\c true) or not.
+ bool local_processed;
+ ///Pointer to the heap cross references.
+ HeapCrossRef *_heap_cross_ref;
+ ///Indicates if \ref _heap_cross_ref is locally allocated (\c true) or not.
+ bool local_heap_cross_ref;
+ ///Pointer to the heap.
+ Heap *_heap;
+ ///Indicates if \ref _heap is locally allocated (\c true) or not.
+ bool local_heap;
+
+ ///Creates the maps if necessary.
+ void create_maps(){
+ if(!_pred) {
+ local_pred = true;
+ _pred = Traits::createPredMap(*graph);
+ }
+ if(!_tree) {
+ local_tree = true;
+ _tree = Traits::createTreeMap(*graph);
+ }
+ if(!_processed) {
+ local_processed = true;
+ _processed = Traits::createProcessedMap(*graph);
+ }
+ if (!_heap_cross_ref) {
+ local_heap_cross_ref = true;
+ _heap_cross_ref = Traits::createHeapCrossRef(*graph);
+ }
+ if (!_heap) {
+ local_heap = true;
+ _heap = Traits::createHeap(*_heap_cross_ref);
+ }
+ }
+
+ public :
+
+ typedef Prim Create;
+
+ ///\name Named template parameters
+
+ ///@{
+
+ template <class T>
+ struct DefPredMapTraits : public Traits {
+ typedef T PredMap;
+ static PredMap *createPredMap(const UGraph &_graph){
+ throw UninitializedParameter();
+ }
+ };
+ ///\ref named-templ-param "Named parameter" for setting PredMap type
+
+ ///\ref named-templ-param "Named parameter" for setting PredMap type
+ ///
+ template <class T>
+ struct DefPredMap
+ : public Prim< UGraph, CostMap, DefPredMapTraits<T> > {
+ typedef Prim< UGraph, CostMap, DefPredMapTraits<T> > Create;
+ };
+
+ template <class T>
+ struct DefProcessedMapTraits : public Traits {
+ typedef T ProcessedMap;
+ static ProcessedMap *createProcessedMap(const UGraph &_graph){
+ throw UninitializedParameter();
+ }
+ };
+ ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
+
+ ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
+ ///
+ template <class T>
+ struct DefProcessedMap
+ : public Prim< UGraph, CostMap, DefProcessedMapTraits<T> > {
+ typedef Prim< UGraph, CostMap, DefProcessedMapTraits<T> > Create;
+ };
+
+ struct DefGraphProcessedMapTraits : public Traits {
+ typedef typename UGraph::template NodeMap<bool> ProcessedMap;
+ static ProcessedMap *createProcessedMap(const UGraph &_graph){
+ return new ProcessedMap(_graph);
+ }
+ };
+
+
+ template <class H, class CR>
+ struct DefHeapTraits : public Traits {
+ typedef CR HeapCrossRef;
+ typedef H Heap;
+ static HeapCrossRef *createHeapCrossRef(const UGraph &) {
+ throw UninitializedParameter();
+ }
+ static Heap *createHeap(HeapCrossRef &){
+ return UninitializedParameter();
+ }
+ };
+ ///\ref named-templ-param "Named parameter" for setting heap and cross
+ ///reference type
+
+ ///\ref named-templ-param "Named parameter" for setting heap and cross
+ ///reference type
+ ///
+ template <class H, class CR = typename UGraph::template NodeMap<int> >
+ struct DefHeap
+ : public Prim< UGraph, CostMap, DefHeapTraits<H, CR> > {
+ typedef Prim< UGraph, CostMap, DefHeapTraits<H, CR> > Create;
+ };
+
+ template <class H, class CR>
+ struct DefStandardHeapTraits : public Traits {
+ typedef CR HeapCrossRef;
+ typedef H Heap;
+ static HeapCrossRef *createHeapCrossRef(const UGraph &_graph) {
+ return new HeapCrossRef(_graph);
+ }
+ static Heap *createHeap(HeapCrossRef &ref){
+ return new Heap(ref);
+ }
+ };
+ ///\ref named-templ-param "Named parameter" for setting heap and cross
+ ///reference type with automatic allocation
+
+ ///\ref named-templ-param "Named parameter" for setting heap and cross
+ ///reference type. It can allocate the heap and the cross reference
+ ///object if the cross reference's constructor waits for the graph as
+ ///parameter and the heap's constructor waits for the cross reference.
+ template <class H, class CR = typename UGraph::template NodeMap<int> >
+ struct DefStandardHeap
+ : public Prim< UGraph, CostMap, DefStandardHeapTraits<H, CR> > {
+ typedef Prim< UGraph, CostMap, DefStandardHeapTraits<H, CR> >
+ Create;
+ };
+
+ template <class TM>
+ struct DefTreeMapTraits : public Traits {
+ typedef TM TreeMap;
+ static TreeMap *createTreeMap(const UGraph &) {
+ throw UninitializedParameter();
+ }
+ };
+ ///\ref named-templ-param "Named parameter" for setting TreeMap
+
+ ///\ref named-templ-param "Named parameter" for setting TreeMap
+ ///
+ template <class TM>
+ struct DefTreeMap
+ : public Prim< UGraph, CostMap, DefTreeMapTraits<TM> > {
+ typedef Prim< UGraph, CostMap, DefTreeMapTraits<TM> > Create;
+ };
+
+ struct DefGraphTreeMapTraits : public Traits {
+ typedef typename UGraph::template NodeMap<bool> TreeMap;
+ static TreeMap *createTreeMap(const UGraph &_graph){
+ return new TreeMap(_graph);
+ }
+ };
+
+ ///@}
+
+
+ protected:
+
+ Prim() {}
+
+ public:
+
+ ///Constructor.
+
+ ///\param _graph the graph the algorithm will run on.
+ ///\param _cost the cost map used by the algorithm.
+ Prim(const UGraph& _graph, const CostMap& _cost) :
+ graph(&_graph), cost(&_cost),
+ _pred(NULL), local_pred(false),
+ _tree(NULL), local_tree(false),
+ _processed(NULL), local_processed(false),
+ _heap_cross_ref(NULL), local_heap_cross_ref(false),
+ _heap(NULL), local_heap(false)
+ {
+ checkConcept<concept::UGraph, UGraph>();
+ }
+
+ ///Destructor.
+ ~Prim(){
+ if(local_pred) delete _pred;
+ if(local_tree) delete _tree;
+ if(local_processed) delete _processed;
+ if(local_heap_cross_ref) delete _heap_cross_ref;
+ if(local_heap) delete _heap;
+ }
+
+ ///\brief Sets the cost map.
+
+ ///Sets the cost map.
+ ///\return <tt> (*this) </tt>
+ Prim &costMap(const CostMap &m){
+ cost = &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 <tt> (*this) </tt>
+ Prim &predMap(PredMap &m){
+ if(local_pred) {
+ delete _pred;
+ local_pred=false;
+ }
+ _pred = &m;
+ return *this;
+ }
+
+ ///\brief Sets the map storing the tree edges.
+
+ ///Sets the map storing the tree 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.
+ ///By default this is a NullMap.
+ ///\return <tt> (*this) </tt>
+ Prim &treeMap(TreeMap &m){
+ if(local_tree) {
+ delete _tree;
+ local_tree=false;
+ }
+ _tree = &m;
+ return *this;
+ }
+
+ ///\brief Sets the heap and the cross reference used by algorithm.
+
+ ///Sets the heap and the cross reference used by 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 <tt> (*this) </tt>
+ Prim &heap(Heap& heap, HeapCrossRef &crossRef){
+ if(local_heap_cross_ref) {
+ delete _heap_cross_ref;
+ local_heap_cross_ref=false;
+ }
+ _heap_cross_ref = &crossRef;
+ if(local_heap) {
+ delete _heap;
+ local_heap=false;
+ }
+ _heap = &heap;
+ return *this;
+ }
+
+ public:
+ ///\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(){
+ create_maps();
+ _heap->clear();
+ for ( NodeIt u(*graph) ; u!=INVALID ; ++u ) {
+ _pred->set(u,INVALID);
+ _processed->set(u,false);
+ _heap_cross_ref->set(u,Heap::PRE_HEAP);
+ }
+ }
+
+ ///\brief Adds a new source node.
+
+ ///Adds a new source node to the priority heap.
+ ///
+ ///It checks if the node has already been added to the heap and
+ ///it is pushed to the heap only if it was not in the heap.
+ void addSource(Node s){
+ if(_heap->state(s) != Heap::IN_HEAP) {
+ _heap->push(s,Value());
+ }
+ }
+ ///\brief Processes the next node in the priority heap
+
+ ///Processes the next node in the priority heap.
+ ///
+ ///\return The processed node.
+ ///
+ ///\warning The priority heap must not be empty!
+ Node processNextNode(){
+ Node v=_heap->top();
+ _heap->pop();
+ _processed->set(v,true);
+
+ for(IncEdgeIt e(*graph,v); e!=INVALID; ++e) {
+ Node w=graph->oppositeNode(v,e);
+ switch(_heap->state(w)) {
+ case Heap::PRE_HEAP:
+ _heap->push(w,(*cost)[e]);
+ _pred->set(w,e);
+ break;
+ case Heap::IN_HEAP:
+ if ( (*cost)[e] < (*_heap)[w] ) {
+ _heap->decrease(w,(*cost)[e]);
+ _pred->set(w,e);
+ }
+ break;
+ case Heap::POST_HEAP:
+ break;
+ }
+ }
+ if ((*_pred)[v]!=INVALID)_tree->set((*_pred)[v],true);
+ return v;
+ }
+
+ ///\brief Next node to be processed.
+
+ ///Next node to be processed.
+ ///
+ ///\return The next node to be processed or INVALID if the priority heap
+ /// is empty.
+ Node nextNode(){
+ return _heap->empty()?_heap->top():INVALID;
+ }
+
+ ///\brief Returns \c false if there are nodes to be processed in the priority heap
+ ///
+ ///Returns \c false if there are nodes
+ ///to be processed in the priority heap
+ bool emptyQueue() { return _heap->empty(); }
+ ///\brief Returns the number of the nodes to be processed in the priority heap
+
+ ///Returns the number of the nodes to be processed in the priority heap
+ ///
+ int queueSize() { return _heap->size(); }
+
+ ///\brief Executes the algorithm.
+
+ ///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 %Prim algorithm from the node(s)
+ ///in order to compute the
+ ///minimum spanning tree.
+ ///
+ void start(){
+ while ( !_heap->empty() ) processNextNode();
+ }
+
+ ///\brief Executes the algorithm until a condition is met.
+
+ ///Executes the algorithm until a condition is met.
+ ///
+ ///\pre init() must be called and at least one node should be added
+ ///with addSource() before using this function.
+ ///
+ ///\param nm must be a bool (or convertible) node map. The algorithm
+ ///will stop when it reaches a node \c v with <tt>nm[v]==true</tt>.
+ template<class NodeBoolMap>
+ void start(const NodeBoolMap &nm){
+ while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode();
+ if ( !_heap->empty() ) _processed->set(_heap->top(),true);
+ }
+
+ ///\brief Runs %Prim algorithm.
+
+ ///This method runs the %Prim algorithm
+ ///in order to compute the
+ ///minimum spanning tree (or minimum spanning forest).
+ ///The method also works on graphs that has more than one components.
+ ///In this case it computes the minimum spanning forest.
+ void run() {
+ init();
+ for(NodeIt it(*graph);it!=INVALID;++it){
+ if(!processed(it)){
+ addSource(it);
+ start();
+ }
+ }
+ }
+
+ ///\brief Runs %Prim algorithm from node \c s.
+
+ ///This method runs the %Prim algorithm from node \c s
+ ///in order to
+ ///compute the
+ ///minimun spanning tree
+ ///
+ ///\note d.run(s) is just a shortcut of the following code.
+ ///\code
+ /// d.init();
+ /// d.addSource(s);
+ /// d.start();
+ ///\endcode
+ ///\note If the graph has more than one components, the method
+ ///will compute the minimun spanning tree for only one component.
+ ///
+ ///See \ref run() if you want to compute the minimal spanning forest.
+ void run(Node s){
+ init();
+ addSource(s);
+ start();
+ }
+
+ ///@}
+
+ ///\name Query Functions
+ ///The result of the %Prim algorithm can be obtained using these
+ ///functions.\n
+ ///Before the use of these functions,
+ ///either run() or start() must be called.
+
+ ///@{
+
+ ///\brief Returns the 'previous edge' of the minimum spanning tree.
+
+ ///For a node \c v it returns the 'previous edge' of the minimum spanning tree,
+ ///i.e. it returns the edge from where \c v was reached. For a source node
+ ///or an unreachable node it is \ref INVALID.
+ ///The minimum spanning tree used here is equal to the minimum spanning tree used
+ ///in \ref predNode(). \pre \ref run() or \ref start() must be called before
+ ///using this function.
+ UEdge predEdge(Node v) const { return (*_pred)[v]; }
+
+ ///\brief Returns the 'previous node' of the minimum spanning tree.
+
+ ///For a node \c v it returns the 'previous node' of the minimum spanning tree,
+ ///i.e. it returns the node from where \c v was reached. For a source node
+ ///or an unreachable node it is \ref INVALID.
+ //The minimum spanning tree used here is equal to the minimum spanning
+ ///tree used in \ref predEdge(). \pre \ref run() or \ref start() 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 the edges of the minimum spanning tree.
+
+ ///Returns a reference to the NodeMap of the edges of the
+ ///minimum spanning tree.
+ ///\pre \ref run() or \ref start() must be called before using this function.
+ const PredMap &predMap() const { return *_pred;}
+
+ ///\brief Returns a reference to the tree edges map.
+
+ ///Returns a reference to the TreeEdgeMap of the edges of the
+ ///minimum spanning tree. The value of the map is \c true only if the edge is in
+ ///the minimum spanning tree.
+ ///\warning By default, the TreeEdgeMap is a NullMap.
+ ///
+ ///If it is not set before the execution of the algorithm, use the \ref
+ ///treeMap(TreeMap&) function (after the execution) to set an UEdgeMap with the
+ ///edges of the minimum spanning tree in O(n) time where n is the number of
+ ///nodes in the graph.
+ ///\pre \ref run() or \ref start() must be called before using this function.
+ const TreeMap &treeMap() const { return *_tree;}
+
+ ///\brief Sets the tree edges map.
+
+ ///Sets the TreeMap of the edges of the minimum spanning tree.
+ ///The map values belonging to the edges of the minimum
+ ///spanning tree are set to \param tree_edge_value or \c true by default,
+ ///the other map values remain untouched.
+ ///
+ ///\pre \ref run() or \ref start() must be called before using this function.
+
+ template<class TreeMap>
+ void quickTreeEdges(
+ TreeMap& tree,
+ const typename TreeMap::Value& tree_edge_value=true) const {
+ for(NodeIt i(*graph);i!=INVALID;++i){
+ if((*_pred)[i]!=INVALID) tree.set((*_pred)[i],tree_edge_value);
+ }
+ }
+
+ ///\brief Sets the tree edges map.
+
+ ///Sets the TreeMap of the edges of the minimum spanning tree.
+ ///The map values belonging to the edges of the minimum
+ ///spanning tree are set to \param tree_edge_value or \c true by default while
+ ///the edge values not belonging to the minimum spanning tree are set to
+ ///\param tree_default_value or \c false by default.
+ ///
+ ///\pre \ref run() or \ref start() must be called before using this function.
+
+ template<class TreeMap>
+ void treeEdges(
+ TreeMap& tree,
+ const typename TreeMap::Value& tree_edge_value=true,
+ const typename TreeMap::Value& tree_default_value=false) const {
+ for(typename ItemSetTraits<UGraph,UEdge>::ItemIt i(*graph);i!=INVALID;++i)
+ tree.set(i,tree_default_value);
+ for(NodeIt i(*graph);i!=INVALID;++i){
+ if((*_pred)[i]!=INVALID) tree.set((*_pred)[i],tree_edge_value);
+ }
+ }
+
+ ///\brief Checks if a node is reachable from the starting node.
+
+ ///Returns \c true if \c v is reachable from the starting node.
+ ///\warning The source nodes are inditated as unreached.
+ ///\pre \ref run() or \ref start() must be called before using this function.
+ ///
+ bool reached(Node v) { return (*_heap_cross_ref)[v] != Heap::PRE_HEAP; }
+
+ ///\brief Checks if a node is processed.
+
+ ///Returns \c true if \c v is processed, i.e. \c v is already connencted to the
+ ///minimum spanning tree.
+ ///\pre \ref run() or \ref start() must be called before using this function.
+ ///
+ bool processed(Node v) { return (*_heap_cross_ref)[v] == Heap::POST_HEAP; }
+
+
+ ///\brief Checks if an edge is in the spanning tree or not.
+
+ ///Checks if an edge is in the spanning tree or not.
+ ///\param e is the edge that will be checked
+ ///\return \c true if e is in the spanning tree, \c false otherwise
+ bool tree(UEdge e){
+ return (*_pred)[*graph.source(e)]==e || (*_pred)[*graph.target(e)]==e;
+ }
+ ///@}
+ };
+
+
+ /// \ingroup spantree
+ ///
+ /// \brief Function type interface for Prim algorithm.
+ ///
+ /// Function type interface for Prim algorithm.
+ /// \param graph the UGraph that the algorithm runs on
+ /// \param cost the CostMap of the edges
+ /// \retval tree the EdgeMap that contains whether an edge is in
+ /// the spanning tree or not
+ ///
+ ///\sa Prim
+ template<class Graph,class CostMap,class TreeMap>
+ void prim(const Graph& graph, const CostMap& cost,TreeMap& tree){
+ typename Prim<Graph,CostMap>::template DefTreeMap<TreeMap>::
+ Create prm(graph,cost);
+ prm.treeMap(tree);
+ prm.run();
+ };
+
+} //END OF NAMESPACE LEMON
+
+#endif
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