Remane GomoryHuTree to GomoryHu (#66)
authorAlpar Juttner <alpar@cs.elte.hu>
Wed, 25 Feb 2009 11:10:57 +0000
changeset 533e72bacfea6b7
parent 532 ccd2d3a3001e
child 534 d6b40ebb2617
Remane GomoryHuTree to GomoryHu (#66)
lemon/Makefile.am
lemon/gomory_hu.h
lemon/gomory_hu_tree.h
test/gomory_hu_test.cc
     1.1 --- a/lemon/Makefile.am	Wed Feb 25 11:10:52 2009 +0000
     1.2 +++ b/lemon/Makefile.am	Wed Feb 25 11:10:57 2009 +0000
     1.3 @@ -68,7 +68,7 @@
     1.4  	lemon/euler.h \
     1.5  	lemon/full_graph.h \
     1.6  	lemon/glpk.h \
     1.7 -	lemon/gomory_hu_tree.h \
     1.8 +	lemon/gomory_hu.h \
     1.9  	lemon/graph_to_eps.h \
    1.10  	lemon/grid_graph.h \
    1.11  	lemon/hypercube_graph.h \
     2.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     2.2 +++ b/lemon/gomory_hu.h	Wed Feb 25 11:10:57 2009 +0000
     2.3 @@ -0,0 +1,554 @@
     2.4 +/* -*- C++ -*-
     2.5 + *
     2.6 + * This file is a part of LEMON, a generic C++ optimization library
     2.7 + *
     2.8 + * Copyright (C) 2003-2008
     2.9 + * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
    2.10 + * (Egervary Research Group on Combinatorial Optimization, EGRES).
    2.11 + *
    2.12 + * Permission to use, modify and distribute this software is granted
    2.13 + * provided that this copyright notice appears in all copies. For
    2.14 + * precise terms see the accompanying LICENSE file.
    2.15 + *
    2.16 + * This software is provided "AS IS" with no warranty of any kind,
    2.17 + * express or implied, and with no claim as to its suitability for any
    2.18 + * purpose.
    2.19 + *
    2.20 + */
    2.21 +
    2.22 +#ifndef LEMON_GOMORY_HU_TREE_H
    2.23 +#define LEMON_GOMORY_HU_TREE_H
    2.24 +
    2.25 +#include <limits>
    2.26 +
    2.27 +#include <lemon/core.h>
    2.28 +#include <lemon/preflow.h>
    2.29 +#include <lemon/concept_check.h>
    2.30 +#include <lemon/concepts/maps.h>
    2.31 +
    2.32 +/// \ingroup min_cut
    2.33 +/// \file 
    2.34 +/// \brief Gomory-Hu cut tree in graphs.
    2.35 +
    2.36 +namespace lemon {
    2.37 +
    2.38 +  /// \ingroup min_cut
    2.39 +  ///
    2.40 +  /// \brief Gomory-Hu cut tree algorithm
    2.41 +  ///
    2.42 +  /// The Gomory-Hu tree is a tree on the node set of the graph, but it
    2.43 +  /// may contain edges which are not in the original digraph. It has the
    2.44 +  /// property that the minimum capacity edge of the path between two nodes 
    2.45 +  /// in this tree has the same weight as the minimum cut in the digraph
    2.46 +  /// between these nodes. Moreover the components obtained by removing
    2.47 +  /// this edge from the tree determine the corresponding minimum cut.
    2.48 +  ///
    2.49 +  /// Therefore once this tree is computed, the minimum cut between any pair
    2.50 +  /// of nodes can easily be obtained.
    2.51 +  /// 
    2.52 +  /// The algorithm calculates \e n-1 distinct minimum cuts (currently with
    2.53 +  /// the \ref Preflow algorithm), therefore the algorithm has
    2.54 +  /// \f$(O(n^3\sqrt{e})\f$ overall time complexity. It calculates a
    2.55 +  /// rooted Gomory-Hu tree, its structure and the weights can be obtained
    2.56 +  /// by \c predNode(), \c predValue() and \c rootDist().
    2.57 +  /// 
    2.58 +  /// The members \c minCutMap() and \c minCutValue() calculate
    2.59 +  /// the minimum cut and the minimum cut value between any two node
    2.60 +  /// in the digraph. You can also list (iterate on) the nodes and the
    2.61 +  /// edges of the cuts using MinCutNodeIt and MinCutEdgeIt.
    2.62 +  ///
    2.63 +  /// \tparam GR The undirected graph data structure the algorithm will run on
    2.64 +  /// \tparam CAP type of the EdgeMap describing the Edge capacities.
    2.65 +  /// it is typename GR::template EdgeMap<int> by default.
    2.66 +  template <typename GR,
    2.67 +	    typename CAP = typename GR::template EdgeMap<int>
    2.68 +            >
    2.69 +  class GomoryHu {
    2.70 +  public:
    2.71 +
    2.72 +    /// The graph type
    2.73 +    typedef GR Graph;
    2.74 +    /// The type if the edge capacity map
    2.75 +    typedef CAP Capacity;
    2.76 +    /// The value type of capacities
    2.77 +    typedef typename Capacity::Value Value;
    2.78 +    
    2.79 +  private:
    2.80 +
    2.81 +    TEMPLATE_GRAPH_TYPEDEFS(Graph);
    2.82 +
    2.83 +    const Graph& _graph;
    2.84 +    const Capacity& _capacity;
    2.85 +
    2.86 +    Node _root;
    2.87 +    typename Graph::template NodeMap<Node>* _pred;
    2.88 +    typename Graph::template NodeMap<Value>* _weight;
    2.89 +    typename Graph::template NodeMap<int>* _order;
    2.90 +
    2.91 +    void createStructures() {
    2.92 +      if (!_pred) {
    2.93 +	_pred = new typename Graph::template NodeMap<Node>(_graph);
    2.94 +      }
    2.95 +      if (!_weight) {
    2.96 +	_weight = new typename Graph::template NodeMap<Value>(_graph);
    2.97 +      }
    2.98 +      if (!_order) {
    2.99 +	_order = new typename Graph::template NodeMap<int>(_graph);
   2.100 +      }
   2.101 +    }
   2.102 +
   2.103 +    void destroyStructures() {
   2.104 +      if (_pred) {
   2.105 +	delete _pred;
   2.106 +      }
   2.107 +      if (_weight) {
   2.108 +	delete _weight;
   2.109 +      }
   2.110 +      if (_order) {
   2.111 +	delete _order;
   2.112 +      }
   2.113 +    }
   2.114 +  
   2.115 +  public:
   2.116 +
   2.117 +    /// \brief Constructor
   2.118 +    ///
   2.119 +    /// Constructor
   2.120 +    /// \param graph The graph the algorithm will run on.
   2.121 +    /// \param capacity The capacity map.
   2.122 +    GomoryHu(const Graph& graph, const Capacity& capacity) 
   2.123 +      : _graph(graph), _capacity(capacity),
   2.124 +	_pred(0), _weight(0), _order(0) 
   2.125 +    {
   2.126 +      checkConcept<concepts::ReadMap<Edge, Value>, Capacity>();
   2.127 +    }
   2.128 +
   2.129 +
   2.130 +    /// \brief Destructor
   2.131 +    ///
   2.132 +    /// Destructor
   2.133 +    ~GomoryHu() {
   2.134 +      destroyStructures();
   2.135 +    }
   2.136 +
   2.137 +    // \brief Initialize the internal data structures.
   2.138 +    //
   2.139 +    // This function initializes the internal data structures.
   2.140 +    //
   2.141 +    void init() {
   2.142 +      createStructures();
   2.143 +
   2.144 +      _root = NodeIt(_graph);
   2.145 +      for (NodeIt n(_graph); n != INVALID; ++n) {
   2.146 +	_pred->set(n, _root);
   2.147 +	_order->set(n, -1);
   2.148 +      }
   2.149 +      _pred->set(_root, INVALID);
   2.150 +      _weight->set(_root, std::numeric_limits<Value>::max()); 
   2.151 +    }
   2.152 +
   2.153 +
   2.154 +    // \brief Start the algorithm
   2.155 +    //
   2.156 +    // This function starts the algorithm.
   2.157 +    //
   2.158 +    // \pre \ref init() must be called before using this function.
   2.159 +    //
   2.160 +    void start() {
   2.161 +      Preflow<Graph, Capacity> fa(_graph, _capacity, _root, INVALID);
   2.162 +
   2.163 +      for (NodeIt n(_graph); n != INVALID; ++n) {
   2.164 +	if (n == _root) continue;
   2.165 +
   2.166 +	Node pn = (*_pred)[n];
   2.167 +	fa.source(n);
   2.168 +	fa.target(pn);
   2.169 +
   2.170 +	fa.runMinCut();
   2.171 +
   2.172 +	_weight->set(n, fa.flowValue());
   2.173 +
   2.174 +	for (NodeIt nn(_graph); nn != INVALID; ++nn) {
   2.175 +	  if (nn != n && fa.minCut(nn) && (*_pred)[nn] == pn) {
   2.176 +	    _pred->set(nn, n);
   2.177 +	  }
   2.178 +	}
   2.179 +	if ((*_pred)[pn] != INVALID && fa.minCut((*_pred)[pn])) {
   2.180 +	  _pred->set(n, (*_pred)[pn]);
   2.181 +	  _pred->set(pn, n);
   2.182 +	  _weight->set(n, (*_weight)[pn]);
   2.183 +	  _weight->set(pn, fa.flowValue());	
   2.184 +	}
   2.185 +      }
   2.186 +
   2.187 +      _order->set(_root, 0);
   2.188 +      int index = 1;
   2.189 +
   2.190 +      for (NodeIt n(_graph); n != INVALID; ++n) {
   2.191 +	std::vector<Node> st;
   2.192 +	Node nn = n;
   2.193 +	while ((*_order)[nn] == -1) {
   2.194 +	  st.push_back(nn);
   2.195 +	  nn = (*_pred)[nn];
   2.196 +	}
   2.197 +	while (!st.empty()) {
   2.198 +	  _order->set(st.back(), index++);
   2.199 +	  st.pop_back();
   2.200 +	}
   2.201 +      }
   2.202 +    }
   2.203 +
   2.204 +    ///\name Execution Control
   2.205 + 
   2.206 +    ///@{
   2.207 +
   2.208 +    /// \brief Run the Gomory-Hu algorithm.
   2.209 +    ///
   2.210 +    /// This function runs the Gomory-Hu algorithm.
   2.211 +    void run() {
   2.212 +      init();
   2.213 +      start();
   2.214 +    }
   2.215 +    
   2.216 +    /// @}
   2.217 +
   2.218 +    ///\name Query Functions
   2.219 +    ///The results of the algorithm can be obtained using these
   2.220 +    ///functions.\n
   2.221 +    ///The \ref run() "run()" should be called before using them.\n
   2.222 +    ///See also MinCutNodeIt and MinCutEdgeIt
   2.223 +
   2.224 +    ///@{
   2.225 +
   2.226 +    /// \brief Return the predecessor node in the Gomory-Hu tree.
   2.227 +    ///
   2.228 +    /// This function returns the predecessor node in the Gomory-Hu tree.
   2.229 +    /// If the node is
   2.230 +    /// the root of the Gomory-Hu tree, then it returns \c INVALID.
   2.231 +    Node predNode(const Node& node) {
   2.232 +      return (*_pred)[node];
   2.233 +    }
   2.234 +
   2.235 +    /// \brief Return the distance from the root node in the Gomory-Hu tree.
   2.236 +    ///
   2.237 +    /// This function returns the distance of \c node from the root node
   2.238 +    /// in the Gomory-Hu tree.
   2.239 +    int rootDist(const Node& node) {
   2.240 +      return (*_order)[node];
   2.241 +    }
   2.242 +
   2.243 +    /// \brief Return the weight of the predecessor edge in the
   2.244 +    /// Gomory-Hu tree.
   2.245 +    ///
   2.246 +    /// This function returns the weight of the predecessor edge in the
   2.247 +    /// Gomory-Hu tree.  If the node is the root, the result is undefined.
   2.248 +    Value predValue(const Node& node) {
   2.249 +      return (*_weight)[node];
   2.250 +    }
   2.251 +
   2.252 +    /// \brief Return the minimum cut value between two nodes
   2.253 +    ///
   2.254 +    /// This function returns the minimum cut value between two nodes. The
   2.255 +    /// algorithm finds the nearest common ancestor in the Gomory-Hu
   2.256 +    /// tree and calculates the minimum weight arc on the paths to
   2.257 +    /// the ancestor.
   2.258 +    Value minCutValue(const Node& s, const Node& t) const {
   2.259 +      Node sn = s, tn = t;
   2.260 +      Value value = std::numeric_limits<Value>::max();
   2.261 +      
   2.262 +      while (sn != tn) {
   2.263 +	if ((*_order)[sn] < (*_order)[tn]) {
   2.264 +	  if ((*_weight)[tn] <= value) value = (*_weight)[tn];
   2.265 +	  tn = (*_pred)[tn];
   2.266 +	} else {
   2.267 +	  if ((*_weight)[sn] <= value) value = (*_weight)[sn];
   2.268 +	  sn = (*_pred)[sn];
   2.269 +	}
   2.270 +      }
   2.271 +      return value;
   2.272 +    }
   2.273 +
   2.274 +    /// \brief Return the minimum cut between two nodes
   2.275 +    ///
   2.276 +    /// This function returns the minimum cut between the nodes \c s and \c t
   2.277 +    /// the \r cutMap parameter by setting the nodes in the component of
   2.278 +    /// \c \s to true and the other nodes to false.
   2.279 +    ///
   2.280 +    /// The \c cutMap should be \ref concepts::ReadWriteMap
   2.281 +    /// "ReadWriteMap".
   2.282 +    ///
   2.283 +    /// For higher level interfaces, see MinCutNodeIt and MinCutEdgeIt
   2.284 +    template <typename CutMap>
   2.285 +    Value minCutMap(const Node& s, ///< Base node
   2.286 +                    const Node& t,
   2.287 +                    ///< The node you want to separate from Node s.
   2.288 +                    CutMap& cutMap
   2.289 +                    ///< The cut will be return in this map.
   2.290 +                    /// It must be a \c bool \ref concepts::ReadWriteMap
   2.291 +                    /// "ReadWriteMap" on the graph nodes.
   2.292 +                    ) const {
   2.293 +      Node sn = s, tn = t;
   2.294 +      bool s_root=false;
   2.295 +      Node rn = INVALID;
   2.296 +      Value value = std::numeric_limits<Value>::max();
   2.297 +      
   2.298 +      while (sn != tn) {
   2.299 +	if ((*_order)[sn] < (*_order)[tn]) {
   2.300 +	  if ((*_weight)[tn] <= value) {
   2.301 +	    rn = tn;
   2.302 +            s_root = false;
   2.303 +	    value = (*_weight)[tn];
   2.304 +	  }
   2.305 +	  tn = (*_pred)[tn];
   2.306 +	} else {
   2.307 +	  if ((*_weight)[sn] <= value) {
   2.308 +	    rn = sn;
   2.309 +            s_root = true;
   2.310 +	    value = (*_weight)[sn];
   2.311 +	  }
   2.312 +	  sn = (*_pred)[sn];
   2.313 +	}
   2.314 +      }
   2.315 +
   2.316 +      typename Graph::template NodeMap<bool> reached(_graph, false);
   2.317 +      reached.set(_root, true);
   2.318 +      cutMap.set(_root, !s_root);
   2.319 +      reached.set(rn, true);
   2.320 +      cutMap.set(rn, s_root);
   2.321 +
   2.322 +      std::vector<Node> st;
   2.323 +      for (NodeIt n(_graph); n != INVALID; ++n) {
   2.324 +	st.clear();
   2.325 +        Node nn = n;
   2.326 +	while (!reached[nn]) {
   2.327 +	  st.push_back(nn);
   2.328 +	  nn = (*_pred)[nn];
   2.329 +	}
   2.330 +	while (!st.empty()) {
   2.331 +	  cutMap.set(st.back(), cutMap[nn]);
   2.332 +	  st.pop_back();
   2.333 +	}
   2.334 +      }
   2.335 +      
   2.336 +      return value;
   2.337 +    }
   2.338 +
   2.339 +    ///@}
   2.340 +
   2.341 +    friend class MinCutNodeIt;
   2.342 +
   2.343 +    /// Iterate on the nodes of a minimum cut
   2.344 +    
   2.345 +    /// This iterator class lists the nodes of a minimum cut found by
   2.346 +    /// GomoryHu. Before using it, you must allocate a GomoryHu class,
   2.347 +    /// and call its \ref GomoryHu::run() "run()" method.
   2.348 +    ///
   2.349 +    /// This example counts the nodes in the minimum cut separating \c s from
   2.350 +    /// \c t.
   2.351 +    /// \code
   2.352 +    /// GomoruHu<Graph> gom(g, capacities);
   2.353 +    /// gom.run();
   2.354 +    /// int sum=0;
   2.355 +    /// for(GomoruHu<Graph>::MinCutNodeIt n(gom,s,t);n!=INVALID;++n) ++sum;
   2.356 +    /// \endcode
   2.357 +    class MinCutNodeIt
   2.358 +    {
   2.359 +      bool _side;
   2.360 +      typename Graph::NodeIt _node_it;
   2.361 +      typename Graph::template NodeMap<bool> _cut;
   2.362 +    public:
   2.363 +      /// Constructor
   2.364 +
   2.365 +      /// Constructor
   2.366 +      ///
   2.367 +      MinCutNodeIt(GomoryHu const &gomory,
   2.368 +                   ///< The GomoryHu class. You must call its
   2.369 +                   ///  run() method
   2.370 +                   ///  before initializing this iterator
   2.371 +                   const Node& s, ///< Base node
   2.372 +                   const Node& t,
   2.373 +                   ///< The node you want to separate from Node s.
   2.374 +                   bool side=true
   2.375 +                   ///< If it is \c true (default) then the iterator lists
   2.376 +                   ///  the nodes of the component containing \c s,
   2.377 +                   ///  otherwise it lists the other component.
   2.378 +                   /// \note As the minimum cut is not always unique,
   2.379 +                   /// \code
   2.380 +                   /// MinCutNodeIt(gomory, s, t, true);
   2.381 +                   /// \endcode
   2.382 +                   /// and
   2.383 +                   /// \code
   2.384 +                   /// MinCutNodeIt(gomory, t, s, false);
   2.385 +                   /// \endcode
   2.386 +                   /// does not necessarily give the same set of nodes.
   2.387 +                   /// However it is ensured that
   2.388 +                   /// \code
   2.389 +                   /// MinCutNodeIt(gomory, s, t, true);
   2.390 +                   /// \endcode
   2.391 +                   /// and
   2.392 +                   /// \code
   2.393 +                   /// MinCutNodeIt(gomory, s, t, false);
   2.394 +                   /// \endcode
   2.395 +                   /// together list each node exactly once.
   2.396 +                   )
   2.397 +        : _side(side), _cut(gomory._graph)
   2.398 +      {
   2.399 +        gomory.minCutMap(s,t,_cut);
   2.400 +        for(_node_it=typename Graph::NodeIt(gomory._graph);
   2.401 +            _node_it!=INVALID && _cut[_node_it]!=_side;
   2.402 +            ++_node_it) {}
   2.403 +      }
   2.404 +      /// Conversion to Node
   2.405 +
   2.406 +      /// Conversion to Node
   2.407 +      ///
   2.408 +      operator typename Graph::Node() const
   2.409 +      {
   2.410 +        return _node_it;
   2.411 +      }
   2.412 +      bool operator==(Invalid) { return _node_it==INVALID; }
   2.413 +      bool operator!=(Invalid) { return _node_it!=INVALID; }
   2.414 +      /// Next node
   2.415 +
   2.416 +      /// Next node
   2.417 +      ///
   2.418 +      MinCutNodeIt &operator++()
   2.419 +      {
   2.420 +        for(++_node_it;_node_it!=INVALID&&_cut[_node_it]!=_side;++_node_it) {}
   2.421 +        return *this;
   2.422 +      }
   2.423 +      /// Postfix incrementation
   2.424 +
   2.425 +      /// Postfix incrementation
   2.426 +      ///
   2.427 +      /// \warning This incrementation
   2.428 +      /// returns a \c Node, not a \ref MinCutNodeIt, as one may
   2.429 +      /// expect.
   2.430 +      typename Graph::Node operator++(int)
   2.431 +      {
   2.432 +        typename Graph::Node n=*this;
   2.433 +        ++(*this);
   2.434 +        return n;
   2.435 +      }
   2.436 +    };
   2.437 +    
   2.438 +    friend class MinCutEdgeIt;
   2.439 +    
   2.440 +    /// Iterate on the edges of a minimum cut
   2.441 +    
   2.442 +    /// This iterator class lists the edges of a minimum cut found by
   2.443 +    /// GomoryHu. Before using it, you must allocate a GomoryHu class,
   2.444 +    /// and call its \ref GomoryHu::run() "run()" method.
   2.445 +    ///
   2.446 +    /// This example computes the value of the minimum cut separating \c s from
   2.447 +    /// \c t.
   2.448 +    /// \code
   2.449 +    /// GomoruHu<Graph> gom(g, capacities);
   2.450 +    /// gom.run();
   2.451 +    /// int value=0;
   2.452 +    /// for(GomoruHu<Graph>::MinCutEdgeIt e(gom,s,t);e!=INVALID;++e)
   2.453 +    ///   value+=capacities[e];
   2.454 +    /// \endcode
   2.455 +    /// the result will be the same as it is returned by
   2.456 +    /// \ref GomoryHu::minCostValue() "gom.minCostValue(s,t)"
   2.457 +    class MinCutEdgeIt
   2.458 +    {
   2.459 +      bool _side;
   2.460 +      const Graph &_graph;
   2.461 +      typename Graph::NodeIt _node_it;
   2.462 +      typename Graph::OutArcIt _arc_it;
   2.463 +      typename Graph::template NodeMap<bool> _cut;
   2.464 +      void step()
   2.465 +      {
   2.466 +        ++_arc_it;
   2.467 +        while(_node_it!=INVALID && _arc_it==INVALID)
   2.468 +          {
   2.469 +            for(++_node_it;_node_it!=INVALID&&!_cut[_node_it];++_node_it) {}
   2.470 +            if(_node_it!=INVALID)
   2.471 +              _arc_it=typename Graph::OutArcIt(_graph,_node_it);
   2.472 +          }
   2.473 +      }
   2.474 +      
   2.475 +    public:
   2.476 +      MinCutEdgeIt(GomoryHu const &gomory,
   2.477 +                   ///< The GomoryHu class. You must call its
   2.478 +                   ///  run() method
   2.479 +                   ///  before initializing this iterator
   2.480 +                   const Node& s,  ///< Base node
   2.481 +                   const Node& t,
   2.482 +                   ///< The node you want to separate from Node s.
   2.483 +                   bool side=true
   2.484 +                   ///< If it is \c true (default) then the listed arcs
   2.485 +                   ///  will be oriented from the
   2.486 +                   ///  the nodes of the component containing \c s,
   2.487 +                   ///  otherwise they will be oriented in the opposite
   2.488 +                   ///  direction.
   2.489 +                   )
   2.490 +        : _graph(gomory._graph), _cut(_graph)
   2.491 +      {
   2.492 +        gomory.minCutMap(s,t,_cut);
   2.493 +        if(!side)
   2.494 +          for(typename Graph::NodeIt n(_graph);n!=INVALID;++n)
   2.495 +            _cut[n]=!_cut[n];
   2.496 +
   2.497 +        for(_node_it=typename Graph::NodeIt(_graph);
   2.498 +            _node_it!=INVALID && !_cut[_node_it];
   2.499 +            ++_node_it) {}
   2.500 +        _arc_it = _node_it!=INVALID ?
   2.501 +          typename Graph::OutArcIt(_graph,_node_it) : INVALID;
   2.502 +        while(_node_it!=INVALID && _arc_it == INVALID)
   2.503 +          {
   2.504 +            for(++_node_it; _node_it!=INVALID&&!_cut[_node_it]; ++_node_it) {}
   2.505 +            if(_node_it!=INVALID)
   2.506 +              _arc_it= typename Graph::OutArcIt(_graph,_node_it);
   2.507 +          }
   2.508 +        while(_arc_it!=INVALID && _cut[_graph.target(_arc_it)]) step();
   2.509 +      }
   2.510 +      /// Conversion to Arc
   2.511 +
   2.512 +      /// Conversion to Arc
   2.513 +      ///
   2.514 +      operator typename Graph::Arc() const
   2.515 +      {
   2.516 +        return _arc_it;
   2.517 +      }
   2.518 +      /// Conversion to Edge
   2.519 +
   2.520 +      /// Conversion to Edge
   2.521 +      ///
   2.522 +      operator typename Graph::Edge() const
   2.523 +      {
   2.524 +        return _arc_it;
   2.525 +      }
   2.526 +      bool operator==(Invalid) { return _node_it==INVALID; }
   2.527 +      bool operator!=(Invalid) { return _node_it!=INVALID; }
   2.528 +      /// Next edge
   2.529 +
   2.530 +      /// Next edge
   2.531 +      ///
   2.532 +      MinCutEdgeIt &operator++()
   2.533 +      {
   2.534 +        step();
   2.535 +        while(_arc_it!=INVALID && _cut[_graph.target(_arc_it)]) step();
   2.536 +        return *this;
   2.537 +      }
   2.538 +      /// Postfix incrementation
   2.539 +      
   2.540 +      /// Postfix incrementation
   2.541 +      ///
   2.542 +      /// \warning This incrementation
   2.543 +      /// returns a \c Arc, not a \ref MinCutEdgeIt, as one may
   2.544 +      /// expect.
   2.545 +      typename Graph::Arc operator++(int)
   2.546 +      {
   2.547 +        typename Graph::Arc e=*this;
   2.548 +        ++(*this);
   2.549 +        return e;
   2.550 +      }
   2.551 +    };
   2.552 +
   2.553 +  };
   2.554 +
   2.555 +}
   2.556 +
   2.557 +#endif
     3.1 --- a/lemon/gomory_hu_tree.h	Wed Feb 25 11:10:52 2009 +0000
     3.2 +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
     3.3 @@ -1,554 +0,0 @@
     3.4 -/* -*- C++ -*-
     3.5 - *
     3.6 - * This file is a part of LEMON, a generic C++ optimization library
     3.7 - *
     3.8 - * Copyright (C) 2003-2008
     3.9 - * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
    3.10 - * (Egervary Research Group on Combinatorial Optimization, EGRES).
    3.11 - *
    3.12 - * Permission to use, modify and distribute this software is granted
    3.13 - * provided that this copyright notice appears in all copies. For
    3.14 - * precise terms see the accompanying LICENSE file.
    3.15 - *
    3.16 - * This software is provided "AS IS" with no warranty of any kind,
    3.17 - * express or implied, and with no claim as to its suitability for any
    3.18 - * purpose.
    3.19 - *
    3.20 - */
    3.21 -
    3.22 -#ifndef LEMON_GOMORY_HU_TREE_H
    3.23 -#define LEMON_GOMORY_HU_TREE_H
    3.24 -
    3.25 -#include <limits>
    3.26 -
    3.27 -#include <lemon/core.h>
    3.28 -#include <lemon/preflow.h>
    3.29 -#include <lemon/concept_check.h>
    3.30 -#include <lemon/concepts/maps.h>
    3.31 -
    3.32 -/// \ingroup min_cut
    3.33 -/// \file 
    3.34 -/// \brief Gomory-Hu cut tree in graphs.
    3.35 -
    3.36 -namespace lemon {
    3.37 -
    3.38 -  /// \ingroup min_cut
    3.39 -  ///
    3.40 -  /// \brief Gomory-Hu cut tree algorithm
    3.41 -  ///
    3.42 -  /// The Gomory-Hu tree is a tree on the node set of the graph, but it
    3.43 -  /// may contain edges which are not in the original digraph. It has the
    3.44 -  /// property that the minimum capacity edge of the path between two nodes 
    3.45 -  /// in this tree has the same weight as the minimum cut in the digraph
    3.46 -  /// between these nodes. Moreover the components obtained by removing
    3.47 -  /// this edge from the tree determine the corresponding minimum cut.
    3.48 -  ///
    3.49 -  /// Therefore once this tree is computed, the minimum cut between any pair
    3.50 -  /// of nodes can easily be obtained.
    3.51 -  /// 
    3.52 -  /// The algorithm calculates \e n-1 distinct minimum cuts (currently with
    3.53 -  /// the \ref Preflow algorithm), therefore the algorithm has
    3.54 -  /// \f$(O(n^3\sqrt{e})\f$ overall time complexity. It calculates a
    3.55 -  /// rooted Gomory-Hu tree, its structure and the weights can be obtained
    3.56 -  /// by \c predNode(), \c predValue() and \c rootDist().
    3.57 -  /// 
    3.58 -  /// The members \c minCutMap() and \c minCutValue() calculate
    3.59 -  /// the minimum cut and the minimum cut value between any two node
    3.60 -  /// in the digraph. You can also list (iterate on) the nodes and the
    3.61 -  /// edges of the cuts using MinCutNodeIt and MinCutEdgeIt.
    3.62 -  ///
    3.63 -  /// \tparam GR The undirected graph data structure the algorithm will run on
    3.64 -  /// \tparam CAP type of the EdgeMap describing the Edge capacities.
    3.65 -  /// it is typename GR::template EdgeMap<int> by default.
    3.66 -  template <typename GR,
    3.67 -	    typename CAP = typename GR::template EdgeMap<int>
    3.68 -            >
    3.69 -  class GomoryHuTree {
    3.70 -  public:
    3.71 -
    3.72 -    /// The graph type
    3.73 -    typedef GR Graph;
    3.74 -    /// The type if the edge capacity map
    3.75 -    typedef CAP Capacity;
    3.76 -    /// The value type of capacities
    3.77 -    typedef typename Capacity::Value Value;
    3.78 -    
    3.79 -  private:
    3.80 -
    3.81 -    TEMPLATE_GRAPH_TYPEDEFS(Graph);
    3.82 -
    3.83 -    const Graph& _graph;
    3.84 -    const Capacity& _capacity;
    3.85 -
    3.86 -    Node _root;
    3.87 -    typename Graph::template NodeMap<Node>* _pred;
    3.88 -    typename Graph::template NodeMap<Value>* _weight;
    3.89 -    typename Graph::template NodeMap<int>* _order;
    3.90 -
    3.91 -    void createStructures() {
    3.92 -      if (!_pred) {
    3.93 -	_pred = new typename Graph::template NodeMap<Node>(_graph);
    3.94 -      }
    3.95 -      if (!_weight) {
    3.96 -	_weight = new typename Graph::template NodeMap<Value>(_graph);
    3.97 -      }
    3.98 -      if (!_order) {
    3.99 -	_order = new typename Graph::template NodeMap<int>(_graph);
   3.100 -      }
   3.101 -    }
   3.102 -
   3.103 -    void destroyStructures() {
   3.104 -      if (_pred) {
   3.105 -	delete _pred;
   3.106 -      }
   3.107 -      if (_weight) {
   3.108 -	delete _weight;
   3.109 -      }
   3.110 -      if (_order) {
   3.111 -	delete _order;
   3.112 -      }
   3.113 -    }
   3.114 -  
   3.115 -  public:
   3.116 -
   3.117 -    /// \brief Constructor
   3.118 -    ///
   3.119 -    /// Constructor
   3.120 -    /// \param graph The graph the algorithm will run on.
   3.121 -    /// \param capacity The capacity map.
   3.122 -    GomoryHuTree(const Graph& graph, const Capacity& capacity) 
   3.123 -      : _graph(graph), _capacity(capacity),
   3.124 -	_pred(0), _weight(0), _order(0) 
   3.125 -    {
   3.126 -      checkConcept<concepts::ReadMap<Edge, Value>, Capacity>();
   3.127 -    }
   3.128 -
   3.129 -
   3.130 -    /// \brief Destructor
   3.131 -    ///
   3.132 -    /// Destructor
   3.133 -    ~GomoryHuTree() {
   3.134 -      destroyStructures();
   3.135 -    }
   3.136 -
   3.137 -    // \brief Initialize the internal data structures.
   3.138 -    //
   3.139 -    // This function initializes the internal data structures.
   3.140 -    //
   3.141 -    void init() {
   3.142 -      createStructures();
   3.143 -
   3.144 -      _root = NodeIt(_graph);
   3.145 -      for (NodeIt n(_graph); n != INVALID; ++n) {
   3.146 -	_pred->set(n, _root);
   3.147 -	_order->set(n, -1);
   3.148 -      }
   3.149 -      _pred->set(_root, INVALID);
   3.150 -      _weight->set(_root, std::numeric_limits<Value>::max()); 
   3.151 -    }
   3.152 -
   3.153 -
   3.154 -    // \brief Start the algorithm
   3.155 -    //
   3.156 -    // This function starts the algorithm.
   3.157 -    //
   3.158 -    // \pre \ref init() must be called before using this function.
   3.159 -    //
   3.160 -    void start() {
   3.161 -      Preflow<Graph, Capacity> fa(_graph, _capacity, _root, INVALID);
   3.162 -
   3.163 -      for (NodeIt n(_graph); n != INVALID; ++n) {
   3.164 -	if (n == _root) continue;
   3.165 -
   3.166 -	Node pn = (*_pred)[n];
   3.167 -	fa.source(n);
   3.168 -	fa.target(pn);
   3.169 -
   3.170 -	fa.runMinCut();
   3.171 -
   3.172 -	_weight->set(n, fa.flowValue());
   3.173 -
   3.174 -	for (NodeIt nn(_graph); nn != INVALID; ++nn) {
   3.175 -	  if (nn != n && fa.minCut(nn) && (*_pred)[nn] == pn) {
   3.176 -	    _pred->set(nn, n);
   3.177 -	  }
   3.178 -	}
   3.179 -	if ((*_pred)[pn] != INVALID && fa.minCut((*_pred)[pn])) {
   3.180 -	  _pred->set(n, (*_pred)[pn]);
   3.181 -	  _pred->set(pn, n);
   3.182 -	  _weight->set(n, (*_weight)[pn]);
   3.183 -	  _weight->set(pn, fa.flowValue());	
   3.184 -	}
   3.185 -      }
   3.186 -
   3.187 -      _order->set(_root, 0);
   3.188 -      int index = 1;
   3.189 -
   3.190 -      for (NodeIt n(_graph); n != INVALID; ++n) {
   3.191 -	std::vector<Node> st;
   3.192 -	Node nn = n;
   3.193 -	while ((*_order)[nn] == -1) {
   3.194 -	  st.push_back(nn);
   3.195 -	  nn = (*_pred)[nn];
   3.196 -	}
   3.197 -	while (!st.empty()) {
   3.198 -	  _order->set(st.back(), index++);
   3.199 -	  st.pop_back();
   3.200 -	}
   3.201 -      }
   3.202 -    }
   3.203 -
   3.204 -    ///\name Execution Control
   3.205 - 
   3.206 -    ///@{
   3.207 -
   3.208 -    /// \brief Run the Gomory-Hu algorithm.
   3.209 -    ///
   3.210 -    /// This function runs the Gomory-Hu algorithm.
   3.211 -    void run() {
   3.212 -      init();
   3.213 -      start();
   3.214 -    }
   3.215 -    
   3.216 -    /// @}
   3.217 -
   3.218 -    ///\name Query Functions
   3.219 -    ///The results of the algorithm can be obtained using these
   3.220 -    ///functions.\n
   3.221 -    ///The \ref run() "run()" should be called before using them.\n
   3.222 -    ///See also MinCutNodeIt and MinCutEdgeIt
   3.223 -
   3.224 -    ///@{
   3.225 -
   3.226 -    /// \brief Return the predecessor node in the Gomory-Hu tree.
   3.227 -    ///
   3.228 -    /// This function returns the predecessor node in the Gomory-Hu tree.
   3.229 -    /// If the node is
   3.230 -    /// the root of the Gomory-Hu tree, then it returns \c INVALID.
   3.231 -    Node predNode(const Node& node) {
   3.232 -      return (*_pred)[node];
   3.233 -    }
   3.234 -
   3.235 -    /// \brief Return the distance from the root node in the Gomory-Hu tree.
   3.236 -    ///
   3.237 -    /// This function returns the distance of \c node from the root node
   3.238 -    /// in the Gomory-Hu tree.
   3.239 -    int rootDist(const Node& node) {
   3.240 -      return (*_order)[node];
   3.241 -    }
   3.242 -
   3.243 -    /// \brief Return the weight of the predecessor edge in the
   3.244 -    /// Gomory-Hu tree.
   3.245 -    ///
   3.246 -    /// This function returns the weight of the predecessor edge in the
   3.247 -    /// Gomory-Hu tree.  If the node is the root, the result is undefined.
   3.248 -    Value predValue(const Node& node) {
   3.249 -      return (*_weight)[node];
   3.250 -    }
   3.251 -
   3.252 -    /// \brief Return the minimum cut value between two nodes
   3.253 -    ///
   3.254 -    /// This function returns the minimum cut value between two nodes. The
   3.255 -    /// algorithm finds the nearest common ancestor in the Gomory-Hu
   3.256 -    /// tree and calculates the minimum weight arc on the paths to
   3.257 -    /// the ancestor.
   3.258 -    Value minCutValue(const Node& s, const Node& t) const {
   3.259 -      Node sn = s, tn = t;
   3.260 -      Value value = std::numeric_limits<Value>::max();
   3.261 -      
   3.262 -      while (sn != tn) {
   3.263 -	if ((*_order)[sn] < (*_order)[tn]) {
   3.264 -	  if ((*_weight)[tn] <= value) value = (*_weight)[tn];
   3.265 -	  tn = (*_pred)[tn];
   3.266 -	} else {
   3.267 -	  if ((*_weight)[sn] <= value) value = (*_weight)[sn];
   3.268 -	  sn = (*_pred)[sn];
   3.269 -	}
   3.270 -      }
   3.271 -      return value;
   3.272 -    }
   3.273 -
   3.274 -    /// \brief Return the minimum cut between two nodes
   3.275 -    ///
   3.276 -    /// This function returns the minimum cut between the nodes \c s and \c t
   3.277 -    /// the \r cutMap parameter by setting the nodes in the component of
   3.278 -    /// \c \s to true and the other nodes to false.
   3.279 -    ///
   3.280 -    /// The \c cutMap should be \ref concepts::ReadWriteMap
   3.281 -    /// "ReadWriteMap".
   3.282 -    ///
   3.283 -    /// For higher level interfaces, see MinCutNodeIt and MinCutEdgeIt
   3.284 -    template <typename CutMap>
   3.285 -    Value minCutMap(const Node& s, ///< Base node
   3.286 -                    const Node& t,
   3.287 -                    ///< The node you want to separate from Node s.
   3.288 -                    CutMap& cutMap
   3.289 -                    ///< The cut will be return in this map.
   3.290 -                    /// It must be a \c bool \ref concepts::ReadWriteMap
   3.291 -                    /// "ReadWriteMap" on the graph nodes.
   3.292 -                    ) const {
   3.293 -      Node sn = s, tn = t;
   3.294 -      bool s_root=false;
   3.295 -      Node rn = INVALID;
   3.296 -      Value value = std::numeric_limits<Value>::max();
   3.297 -      
   3.298 -      while (sn != tn) {
   3.299 -	if ((*_order)[sn] < (*_order)[tn]) {
   3.300 -	  if ((*_weight)[tn] <= value) {
   3.301 -	    rn = tn;
   3.302 -            s_root = false;
   3.303 -	    value = (*_weight)[tn];
   3.304 -	  }
   3.305 -	  tn = (*_pred)[tn];
   3.306 -	} else {
   3.307 -	  if ((*_weight)[sn] <= value) {
   3.308 -	    rn = sn;
   3.309 -            s_root = true;
   3.310 -	    value = (*_weight)[sn];
   3.311 -	  }
   3.312 -	  sn = (*_pred)[sn];
   3.313 -	}
   3.314 -      }
   3.315 -
   3.316 -      typename Graph::template NodeMap<bool> reached(_graph, false);
   3.317 -      reached.set(_root, true);
   3.318 -      cutMap.set(_root, !s_root);
   3.319 -      reached.set(rn, true);
   3.320 -      cutMap.set(rn, s_root);
   3.321 -
   3.322 -      std::vector<Node> st;
   3.323 -      for (NodeIt n(_graph); n != INVALID; ++n) {
   3.324 -	st.clear();
   3.325 -        Node nn = n;
   3.326 -	while (!reached[nn]) {
   3.327 -	  st.push_back(nn);
   3.328 -	  nn = (*_pred)[nn];
   3.329 -	}
   3.330 -	while (!st.empty()) {
   3.331 -	  cutMap.set(st.back(), cutMap[nn]);
   3.332 -	  st.pop_back();
   3.333 -	}
   3.334 -      }
   3.335 -      
   3.336 -      return value;
   3.337 -    }
   3.338 -
   3.339 -    ///@}
   3.340 -
   3.341 -    friend class MinCutNodeIt;
   3.342 -
   3.343 -    /// Iterate on the nodes of a minimum cut
   3.344 -    
   3.345 -    /// This iterator class lists the nodes of a minimum cut found by
   3.346 -    /// GomoryHuTree. Before using it, you must allocate a GomoryHuTree class,
   3.347 -    /// and call its \ref GomoryHuTree::run() "run()" method.
   3.348 -    ///
   3.349 -    /// This example counts the nodes in the minimum cut separating \c s from
   3.350 -    /// \c t.
   3.351 -    /// \code
   3.352 -    /// GomoruHuTree<Graph> gom(g, capacities);
   3.353 -    /// gom.run();
   3.354 -    /// int sum=0;
   3.355 -    /// for(GomoruHuTree<Graph>::MinCutNodeIt n(gom,s,t);n!=INVALID;++n) ++sum;
   3.356 -    /// \endcode
   3.357 -    class MinCutNodeIt
   3.358 -    {
   3.359 -      bool _side;
   3.360 -      typename Graph::NodeIt _node_it;
   3.361 -      typename Graph::template NodeMap<bool> _cut;
   3.362 -    public:
   3.363 -      /// Constructor
   3.364 -
   3.365 -      /// Constructor
   3.366 -      ///
   3.367 -      MinCutNodeIt(GomoryHuTree const &gomory,
   3.368 -                   ///< The GomoryHuTree class. You must call its
   3.369 -                   ///  run() method
   3.370 -                   ///  before initializing this iterator
   3.371 -                   const Node& s, ///< Base node
   3.372 -                   const Node& t,
   3.373 -                   ///< The node you want to separate from Node s.
   3.374 -                   bool side=true
   3.375 -                   ///< If it is \c true (default) then the iterator lists
   3.376 -                   ///  the nodes of the component containing \c s,
   3.377 -                   ///  otherwise it lists the other component.
   3.378 -                   /// \note As the minimum cut is not always unique,
   3.379 -                   /// \code
   3.380 -                   /// MinCutNodeIt(gomory, s, t, true);
   3.381 -                   /// \endcode
   3.382 -                   /// and
   3.383 -                   /// \code
   3.384 -                   /// MinCutNodeIt(gomory, t, s, false);
   3.385 -                   /// \endcode
   3.386 -                   /// does not necessarily give the same set of nodes.
   3.387 -                   /// However it is ensured that
   3.388 -                   /// \code
   3.389 -                   /// MinCutNodeIt(gomory, s, t, true);
   3.390 -                   /// \endcode
   3.391 -                   /// and
   3.392 -                   /// \code
   3.393 -                   /// MinCutNodeIt(gomory, s, t, false);
   3.394 -                   /// \endcode
   3.395 -                   /// together list each node exactly once.
   3.396 -                   )
   3.397 -        : _side(side), _cut(gomory._graph)
   3.398 -      {
   3.399 -        gomory.minCutMap(s,t,_cut);
   3.400 -        for(_node_it=typename Graph::NodeIt(gomory._graph);
   3.401 -            _node_it!=INVALID && _cut[_node_it]!=_side;
   3.402 -            ++_node_it) {}
   3.403 -      }
   3.404 -      /// Conversion to Node
   3.405 -
   3.406 -      /// Conversion to Node
   3.407 -      ///
   3.408 -      operator typename Graph::Node() const
   3.409 -      {
   3.410 -        return _node_it;
   3.411 -      }
   3.412 -      bool operator==(Invalid) { return _node_it==INVALID; }
   3.413 -      bool operator!=(Invalid) { return _node_it!=INVALID; }
   3.414 -      /// Next node
   3.415 -
   3.416 -      /// Next node
   3.417 -      ///
   3.418 -      MinCutNodeIt &operator++()
   3.419 -      {
   3.420 -        for(++_node_it;_node_it!=INVALID&&_cut[_node_it]!=_side;++_node_it) {}
   3.421 -        return *this;
   3.422 -      }
   3.423 -      /// Postfix incrementation
   3.424 -
   3.425 -      /// Postfix incrementation
   3.426 -      ///
   3.427 -      /// \warning This incrementation
   3.428 -      /// returns a \c Node, not a \ref MinCutNodeIt, as one may
   3.429 -      /// expect.
   3.430 -      typename Graph::Node operator++(int)
   3.431 -      {
   3.432 -        typename Graph::Node n=*this;
   3.433 -        ++(*this);
   3.434 -        return n;
   3.435 -      }
   3.436 -    };
   3.437 -    
   3.438 -    friend class MinCutEdgeIt;
   3.439 -    
   3.440 -    /// Iterate on the edges of a minimum cut
   3.441 -    
   3.442 -    /// This iterator class lists the edges of a minimum cut found by
   3.443 -    /// GomoryHuTree. Before using it, you must allocate a GomoryHuTree class,
   3.444 -    /// and call its \ref GomoryHuTree::run() "run()" method.
   3.445 -    ///
   3.446 -    /// This example computes the value of the minimum cut separating \c s from
   3.447 -    /// \c t.
   3.448 -    /// \code
   3.449 -    /// GomoruHuTree<Graph> gom(g, capacities);
   3.450 -    /// gom.run();
   3.451 -    /// int value=0;
   3.452 -    /// for(GomoruHuTree<Graph>::MinCutEdgeIt e(gom,s,t);e!=INVALID;++e)
   3.453 -    ///   value+=capacities[e];
   3.454 -    /// \endcode
   3.455 -    /// the result will be the same as it is returned by
   3.456 -    /// \ref GomoryHuTree::minCostValue() "gom.minCostValue(s,t)"
   3.457 -    class MinCutEdgeIt
   3.458 -    {
   3.459 -      bool _side;
   3.460 -      const Graph &_graph;
   3.461 -      typename Graph::NodeIt _node_it;
   3.462 -      typename Graph::OutArcIt _arc_it;
   3.463 -      typename Graph::template NodeMap<bool> _cut;
   3.464 -      void step()
   3.465 -      {
   3.466 -        ++_arc_it;
   3.467 -        while(_node_it!=INVALID && _arc_it==INVALID)
   3.468 -          {
   3.469 -            for(++_node_it;_node_it!=INVALID&&!_cut[_node_it];++_node_it) {}
   3.470 -            if(_node_it!=INVALID)
   3.471 -              _arc_it=typename Graph::OutArcIt(_graph,_node_it);
   3.472 -          }
   3.473 -      }
   3.474 -      
   3.475 -    public:
   3.476 -      MinCutEdgeIt(GomoryHuTree const &gomory,
   3.477 -                   ///< The GomoryHuTree class. You must call its
   3.478 -                   ///  run() method
   3.479 -                   ///  before initializing this iterator
   3.480 -                   const Node& s,  ///< Base node
   3.481 -                   const Node& t,
   3.482 -                   ///< The node you want to separate from Node s.
   3.483 -                   bool side=true
   3.484 -                   ///< If it is \c true (default) then the listed arcs
   3.485 -                   ///  will be oriented from the
   3.486 -                   ///  the nodes of the component containing \c s,
   3.487 -                   ///  otherwise they will be oriented in the opposite
   3.488 -                   ///  direction.
   3.489 -                   )
   3.490 -        : _graph(gomory._graph), _cut(_graph)
   3.491 -      {
   3.492 -        gomory.minCutMap(s,t,_cut);
   3.493 -        if(!side)
   3.494 -          for(typename Graph::NodeIt n(_graph);n!=INVALID;++n)
   3.495 -            _cut[n]=!_cut[n];
   3.496 -
   3.497 -        for(_node_it=typename Graph::NodeIt(_graph);
   3.498 -            _node_it!=INVALID && !_cut[_node_it];
   3.499 -            ++_node_it) {}
   3.500 -        _arc_it = _node_it!=INVALID ?
   3.501 -          typename Graph::OutArcIt(_graph,_node_it) : INVALID;
   3.502 -        while(_node_it!=INVALID && _arc_it == INVALID)
   3.503 -          {
   3.504 -            for(++_node_it; _node_it!=INVALID&&!_cut[_node_it]; ++_node_it) {}
   3.505 -            if(_node_it!=INVALID)
   3.506 -              _arc_it= typename Graph::OutArcIt(_graph,_node_it);
   3.507 -          }
   3.508 -        while(_arc_it!=INVALID && _cut[_graph.target(_arc_it)]) step();
   3.509 -      }
   3.510 -      /// Conversion to Arc
   3.511 -
   3.512 -      /// Conversion to Arc
   3.513 -      ///
   3.514 -      operator typename Graph::Arc() const
   3.515 -      {
   3.516 -        return _arc_it;
   3.517 -      }
   3.518 -      /// Conversion to Edge
   3.519 -
   3.520 -      /// Conversion to Edge
   3.521 -      ///
   3.522 -      operator typename Graph::Edge() const
   3.523 -      {
   3.524 -        return _arc_it;
   3.525 -      }
   3.526 -      bool operator==(Invalid) { return _node_it==INVALID; }
   3.527 -      bool operator!=(Invalid) { return _node_it!=INVALID; }
   3.528 -      /// Next edge
   3.529 -
   3.530 -      /// Next edge
   3.531 -      ///
   3.532 -      MinCutEdgeIt &operator++()
   3.533 -      {
   3.534 -        step();
   3.535 -        while(_arc_it!=INVALID && _cut[_graph.target(_arc_it)]) step();
   3.536 -        return *this;
   3.537 -      }
   3.538 -      /// Postfix incrementation
   3.539 -      
   3.540 -      /// Postfix incrementation
   3.541 -      ///
   3.542 -      /// \warning This incrementation
   3.543 -      /// returns a \c Arc, not a \ref MinCutEdgeIt, as one may
   3.544 -      /// expect.
   3.545 -      typename Graph::Arc operator++(int)
   3.546 -      {
   3.547 -        typename Graph::Arc e=*this;
   3.548 -        ++(*this);
   3.549 -        return e;
   3.550 -      }
   3.551 -    };
   3.552 -
   3.553 -  };
   3.554 -
   3.555 -}
   3.556 -
   3.557 -#endif
     4.1 --- a/test/gomory_hu_test.cc	Wed Feb 25 11:10:52 2009 +0000
     4.2 +++ b/test/gomory_hu_test.cc	Wed Feb 25 11:10:57 2009 +0000
     4.3 @@ -3,7 +3,7 @@
     4.4  #include "test_tools.h"
     4.5  #include <lemon/smart_graph.h>
     4.6  #include <lemon/lgf_reader.h>
     4.7 -#include <lemon/gomory_hu_tree.h>
     4.8 +#include <lemon/gomory_hu.h>
     4.9  #include <cstdlib>
    4.10  
    4.11  using namespace std;
    4.12 @@ -60,7 +60,7 @@
    4.13    GraphReader<Graph>(graph, input).
    4.14      edgeMap("capacity", capacity).run();
    4.15  
    4.16 -  GomoryHuTree<Graph> ght(graph, capacity);
    4.17 +  GomoryHu<Graph> ght(graph, capacity);
    4.18    ght.init();
    4.19    ght.run();
    4.20  
    4.21 @@ -75,14 +75,14 @@
    4.22        check(pf.flowValue() == cutValue(graph, cm, capacity), "Wrong cut 2");
    4.23  
    4.24        int sum=0;
    4.25 -      for(GomoryHuTree<Graph>::MinCutEdgeIt a(ght, u, v);a!=INVALID;++a)
    4.26 +      for(GomoryHu<Graph>::MinCutEdgeIt a(ght, u, v);a!=INVALID;++a)
    4.27          sum+=capacity[a]; 
    4.28        check(sum == ght.minCutValue(u, v), "Problem with MinCutEdgeIt");
    4.29  
    4.30        sum=0;
    4.31 -      for(GomoryHuTree<Graph>::MinCutNodeIt n(ght, u, v,true);n!=INVALID;++n)
    4.32 +      for(GomoryHu<Graph>::MinCutNodeIt n(ght, u, v,true);n!=INVALID;++n)
    4.33          sum++;
    4.34 -      for(GomoryHuTree<Graph>::MinCutNodeIt n(ght, u, v,false);n!=INVALID;++n)
    4.35 +      for(GomoryHu<Graph>::MinCutNodeIt n(ght, u, v,false);n!=INVALID;++n)
    4.36          sum++;
    4.37        check(sum == countNodes(graph), "Problem with MinCutNodeIt");
    4.38