#include <vector>

 #include <vector>

 #include <queue>

 #include <queue>

 #include <lemon/error.h>

 #include <lemon/error.h>

 #include <lemon/invalid.h>

 #include <lemon/invalid.h>

 #include <lemon/maps.h>

 #include <lemon/maps.h>

 #include <lemon/graph_utils.h>

 #include <lemon/graph_utils.h>

 /// \file

 /// \file

 /// \ingroup flowalgs

 /// \ingroup flowalgs

   ///

   ///

   ///\author Jacint Szabo 

   ///\author Jacint Szabo 

   ///\todo Second template parameter is superfluous

   ///\todo Second template parameter is superfluous

   template <typename Graph, typename Num,

   template <typename Graph, typename Num,

 	    typename CapacityMap=typename Graph::template EdgeMap<Num>,

 	    typename CapacityMap=typename Graph::template EdgeMap<Num>,

   class Preflow {

   class Preflow {

   protected:

   protected:

     typedef typename Graph::Node Node;

     typedef typename Graph::Node Node;

     typedef typename Graph::NodeIt NodeIt;

     typedef typename Graph::NodeIt NodeIt;

     typedef typename Graph::EdgeIt EdgeIt;

     typedef typename Graph::EdgeIt EdgeIt;

     const Graph* _g;

     const Graph* _g;

     Node _source;

     Node _source;

     Node _target;

     Node _target;

     const CapacityMap* _capacity;

     const CapacityMap* _capacity;

     FlowMap* _flow;

     FlowMap* _flow;

     int _node_num;      //the number of nodes of G

     int _node_num;      //the number of nodes of G

     typename Graph::template NodeMap<int> level;  

     typename Graph::template NodeMap<int> level;  

     typename Graph::template NodeMap<Num> excess;

     typename Graph::template NodeMap<Num> excess;

     ///\param _f The flow of the edges. 

     ///\param _f The flow of the edges. 

     ///Except the graph, all of these parameters can be reset by

     ///Except the graph, all of these parameters can be reset by

     ///calling \ref source, \ref target, \ref capacityMap and \ref

     ///calling \ref source, \ref target, \ref capacityMap and \ref

     ///flowMap, resp.

     ///flowMap, resp.

       Preflow(const Graph& _gr, Node _s, Node _t, 

       Preflow(const Graph& _gr, Node _s, Node _t, 

 	_g(&_gr), _source(_s), _target(_t), _capacity(&_cap),

 	_g(&_gr), _source(_s), _target(_t), _capacity(&_cap),

 	flow_prop(NO_FLOW), status(AFTER_NOTHING) { 

 	flow_prop(NO_FLOW), status(AFTER_NOTHING) { 

 	if ( _source==_target )

 	if ( _source==_target )

 	  throw InvalidArgument();

 	  throw InvalidArgument();

       }

       }