# HG changeset patch
# User marci
# Date 1083255961 0
# Node ID 8c74de352f80a76d10d83d3b366fce3a2ae4be18
# Parent  02b8ddcb207ae272cb538bd4a17a104e0e03e895
preflow.f -> max_flow.h

diff -r 02b8ddcb207a -r 8c74de352f80 src/work/jacint/max_flow.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/jacint/max_flow.h	Thu Apr 29 16:26:01 2004 +0000
@@ -0,0 +1,1016 @@
+// -*- C++ -*-
+
+/*
+Heuristics: 
+ 2 phase
+ gap
+ list 'level_list' on the nodes on level i implemented by hand
+ stack 'active' on the active nodes on level i
+ runs heuristic 'highest label' for H1*n relabels
+ runs heuristic 'bound decrease' for H0*n relabels, starts with 'highest label'
+ 
+Parameters H0 and H1 are initialized to 20 and 1.
+
+Constructors:
+
+Preflow(Graph, Node, Node, CapMap, FlowMap, bool) : bool must be false if 
+     FlowMap is not constant zero, and should be true if it is
+
+Members:
+
+void run()
+
+Num flowValue() : returns the value of a maximum flow
+
+void minMinCut(CutMap& M) : sets M to the characteristic vector of the 
+     minimum min cut. M should be a map of bools initialized to false. ??Is it OK?
+
+void maxMinCut(CutMap& M) : sets M to the characteristic vector of the 
+     maximum min cut. M should be a map of bools initialized to false.
+
+void minCut(CutMap& M) : sets M to the characteristic vector of 
+     a min cut. M should be a map of bools initialized to false.
+
+*/
+
+#ifndef HUGO_PREFLOW_H
+#define HUGO_PREFLOW_H
+
+#define H0 20
+#define H1 1
+
+#include <vector>
+#include <queue>
+#include <stack>
+
+#include <graph_wrapper.h>
+#include <bfs_iterator.h>
+#include <invalid.h>
+#include <maps.h>
+#include <for_each_macros.h>
+
+
+namespace hugo {
+
+  template <typename Graph, typename Num, 
+	    typename CapMap=typename Graph::template EdgeMap<Num>, 
+            typename FlowMap=typename Graph::template EdgeMap<Num> >
+  class MaxFlow {
+    
+    typedef typename Graph::Node Node;
+    typedef typename Graph::NodeIt NodeIt;
+    typedef typename Graph::OutEdgeIt OutEdgeIt;
+    typedef typename Graph::InEdgeIt InEdgeIt;
+
+    typedef typename std::vector<std::stack<Node> > VecStack;
+    typedef typename Graph::template NodeMap<Node> NNMap;
+    typedef typename std::vector<Node> VecNode;
+
+    const Graph* g;
+    Node s;
+    Node t;
+    const CapMap* capacity;  
+    FlowMap* flow;
+    int n;      //the number of nodes of G
+    typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
+    typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
+    typedef typename ResGW::Edge ResGWEdge;
+    //typedef typename ResGW::template NodeMap<bool> ReachedMap;
+    typedef typename Graph::template NodeMap<int> ReachedMap;
+    ReachedMap level;
+    //level works as a bool map in augmenting path algorithms 
+    //and is used by bfs for storing reached information.
+    //In preflow, it shows levels of nodes.
+    //typename Graph::template NodeMap<int> level;    
+    typename Graph::template NodeMap<Num> excess; 
+
+  public:
+ 
+    enum flowEnum{
+      ZERO_FLOW=0,
+      GEN_FLOW=1,
+      PREFLOW=2
+    };
+
+    MaxFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity, 
+	    FlowMap& _flow) :
+      g(&_G), s(_s), t(_t), capacity(&_capacity), 
+      flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0) {}
+
+    void run() {
+      preflow( ZERO_FLOW );
+    }
+    
+    void preflow( flowEnum fe ) {
+      preflowPhase0(fe);
+      preflowPhase1();
+    }
+
+    void preflowPhase0( flowEnum fe );
+
+    void preflowPhase1();
+
+    bool augmentOnShortestPath();
+
+    template<typename MutableGraph> bool augmentOnBlockingFlow();
+
+    bool augmentOnBlockingFlow2();
+
+    /// Returns the actual flow value.
+    /// More precisely, it returns the negative excess of s, thus 
+    /// this works also for preflows.
+    Num flowValue() { 
+      Num a=0;
+      FOR_EACH_INC_LOC(OutEdgeIt, e, *g, s) a+=(*flow)[e];
+      FOR_EACH_INC_LOC(InEdgeIt, e, *g, s) a-=(*flow)[e];
+      return a;
+    }
+
+    //should be used only between preflowPhase0 and preflowPhase1
+    template<typename _CutMap>
+    void actMinCut(_CutMap& M) {
+      NodeIt v;
+      for(g->first(v); g->valid(v); g->next(v)) 
+      if ( level[v] < n ) {
+	M.set(v,false);
+      } else {
+	M.set(v,true);
+      }
+    }
+
+
+
+    /*
+      Returns the minimum min cut, by a bfs from s in the residual graph.
+    */
+    template<typename _CutMap>
+    void minMinCut(_CutMap& M) {
+    
+      std::queue<Node> queue;
+      
+      M.set(s,true);      
+      queue.push(s);
+
+      while (!queue.empty()) {
+        Node w=queue.front();
+	queue.pop();
+
+	OutEdgeIt e;
+	for(g->first(e,w) ; g->valid(e); g->next(e)) {
+	  Node v=g->head(e);
+	  if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
+	    queue.push(v);
+	    M.set(v, true);
+	  }
+	} 
+
+	InEdgeIt f;
+	for(g->first(f,w) ; g->valid(f); g->next(f)) {
+	  Node v=g->tail(f);
+	  if (!M[v] && (*flow)[f] > 0 ) {
+	    queue.push(v);
+	    M.set(v, true);
+	  }
+	} 
+      }
+    }
+
+
+  
+    /*
+      Returns the maximum min cut, by a reverse bfs 
+      from t in the residual graph.
+    */
+    
+    template<typename _CutMap>
+    void maxMinCut(_CutMap& M) {
+
+      NodeIt v;
+      for(g->first(v) ; g->valid(v); g->next(v)) {
+	M.set(v, true);
+      }
+
+      std::queue<Node> queue;
+      
+      M.set(t,false);        
+      queue.push(t);
+
+      while (!queue.empty()) {
+        Node w=queue.front();
+	queue.pop();
+
+
+	InEdgeIt e;
+	for(g->first(e,w) ; g->valid(e); g->next(e)) {
+	  Node v=g->tail(e);
+	  if (M[v] && (*flow)[e] < (*capacity)[e] ) {
+	    queue.push(v);
+	    M.set(v, false);
+	  }
+	}
+	
+	OutEdgeIt f;
+	for(g->first(f,w) ; g->valid(f); g->next(f)) {
+	  Node v=g->head(f);
+	  if (M[v] && (*flow)[f] > 0 ) {
+	    queue.push(v);
+	    M.set(v, false);
+	  }
+	}
+      }
+    }
+
+
+    template<typename CutMap>
+    void minCut(CutMap& M) {
+      minMinCut(M);
+    }
+
+    void resetTarget(Node _t) {t=_t;}
+    void resetSource(Node _s) {s=_s;}
+   
+    void resetCap(const CapMap& _cap) {
+      capacity=&_cap;
+    }
+    
+    void resetFlow(FlowMap& _flow) {
+      flow=&_flow;
+    }
+
+
+  private:
+
+    int push(Node w, VecStack& active) {
+      
+      int lev=level[w];
+      Num exc=excess[w];
+      int newlevel=n;       //bound on the next level of w
+	  
+      OutEdgeIt e;
+      for(g->first(e,w); g->valid(e); g->next(e)) {
+	    
+	if ( (*flow)[e] >= (*capacity)[e] ) continue; 
+	Node v=g->head(e);            
+	    
+	if( lev > level[v] ) { //Push is allowed now
+	  
+	  if ( excess[v]<=0 && v!=t && v!=s ) {
+	    int lev_v=level[v];
+	    active[lev_v].push(v);
+	  }
+	  
+	  Num cap=(*capacity)[e];
+	  Num flo=(*flow)[e];
+	  Num remcap=cap-flo;
+	  
+	  if ( remcap >= exc ) { //A nonsaturating push.
+	    
+	    flow->set(e, flo+exc);
+	    excess.set(v, excess[v]+exc);
+	    exc=0;
+	    break; 
+	    
+	  } else { //A saturating push.
+	    flow->set(e, cap);
+	    excess.set(v, excess[v]+remcap);
+	    exc-=remcap;
+	  }
+	} else if ( newlevel > level[v] ) newlevel = level[v];
+      } //for out edges wv 
+      
+      if ( exc > 0 ) {	
+	InEdgeIt e;
+	for(g->first(e,w); g->valid(e); g->next(e)) {
+	  
+	  if( (*flow)[e] <= 0 ) continue; 
+	  Node v=g->tail(e); 
+	  
+	  if( lev > level[v] ) { //Push is allowed now
+	    
+	    if ( excess[v]<=0 && v!=t && v!=s ) {
+	      int lev_v=level[v];
+	      active[lev_v].push(v);
+	    }
+	    
+	    Num flo=(*flow)[e];
+	    
+	    if ( flo >= exc ) { //A nonsaturating push.
+	      
+	      flow->set(e, flo-exc);
+	      excess.set(v, excess[v]+exc);
+	      exc=0;
+	      break; 
+	    } else {  //A saturating push.
+	      
+	      excess.set(v, excess[v]+flo);
+	      exc-=flo;
+	      flow->set(e,0);
+	    }  
+	  } else if ( newlevel > level[v] ) newlevel = level[v];
+	} //for in edges vw
+	
+      } // if w still has excess after the out edge for cycle
+      
+      excess.set(w, exc);
+      
+      return newlevel;
+     }
+
+
+    void preflowPreproc ( flowEnum fe, VecStack& active, 
+			  VecNode& level_list, NNMap& left, NNMap& right ) {
+
+      std::queue<Node> bfs_queue;
+      
+      switch ( fe ) {
+      case ZERO_FLOW: 
+	{
+	  //Reverse_bfs from t, to find the starting level.
+	  level.set(t,0);
+	  bfs_queue.push(t);
+	
+	  while (!bfs_queue.empty()) {
+	    
+	    Node v=bfs_queue.front();	
+	    bfs_queue.pop();
+	    int l=level[v]+1;
+	    
+	    InEdgeIt e;
+	    for(g->first(e,v); g->valid(e); g->next(e)) {
+	      Node w=g->tail(e);
+	      if ( level[w] == n && w != s ) {
+		bfs_queue.push(w);
+		Node first=level_list[l];
+		if ( g->valid(first) ) left.set(first,w);
+		right.set(w,first);
+		level_list[l]=w;
+		level.set(w, l);
+	      }
+	    }
+	  }
+	  
+	  //the starting flow
+	  OutEdgeIt e;
+	  for(g->first(e,s); g->valid(e); g->next(e)) 
+	    {
+	      Num c=(*capacity)[e];
+	      if ( c <= 0 ) continue;
+	      Node w=g->head(e);
+	      if ( level[w] < n ) {	  
+		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
+		flow->set(e, c); 
+		excess.set(w, excess[w]+c);
+	      }
+	    }
+	  break;
+	}
+	
+      case GEN_FLOW:
+      case PREFLOW:
+	{
+	  //Reverse_bfs from t in the residual graph, 
+	  //to find the starting level.
+	  level.set(t,0);
+	  bfs_queue.push(t);
+	  
+	  while (!bfs_queue.empty()) {
+	    
+	    Node v=bfs_queue.front();	
+	    bfs_queue.pop();
+	    int l=level[v]+1;
+	    
+	    InEdgeIt e;
+	    for(g->first(e,v); g->valid(e); g->next(e)) {
+	      if ( (*capacity)[e] <= (*flow)[e] ) continue;
+	      Node w=g->tail(e);
+	      if ( level[w] == n && w != s ) {
+		bfs_queue.push(w);
+		Node first=level_list[l];
+		if ( g->valid(first) ) left.set(first,w);
+		right.set(w,first);
+		level_list[l]=w;
+		level.set(w, l);
+	      }
+	    }
+	    
+	    OutEdgeIt f;
+	    for(g->first(f,v); g->valid(f); g->next(f)) {
+	      if ( 0 >= (*flow)[f] ) continue;
+	      Node w=g->head(f);
+	      if ( level[w] == n && w != s ) {
+		bfs_queue.push(w);
+		Node first=level_list[l];
+		if ( g->valid(first) ) left.set(first,w);
+		right.set(w,first);
+		level_list[l]=w;
+		level.set(w, l);
+	      }
+	    }
+	  }
+	  
+	  
+	  //the starting flow
+	  OutEdgeIt e;
+	  for(g->first(e,s); g->valid(e); g->next(e)) 
+	    {
+	      Num rem=(*capacity)[e]-(*flow)[e];
+	      if ( rem <= 0 ) continue;
+	      Node w=g->head(e);
+	      if ( level[w] < n ) {	  
+		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
+		flow->set(e, (*capacity)[e]); 
+		excess.set(w, excess[w]+rem);
+	      }
+	    }
+	  
+	  InEdgeIt f;
+	  for(g->first(f,s); g->valid(f); g->next(f)) 
+	    {
+	      if ( (*flow)[f] <= 0 ) continue;
+	      Node w=g->tail(f);
+	      if ( level[w] < n ) {	  
+		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
+		excess.set(w, excess[w]+(*flow)[f]);
+		flow->set(f, 0); 
+	      }
+	    }  
+	  break;
+	} //case PREFLOW
+      }
+    } //preflowPreproc
+
+
+
+    void relabel(Node w, int newlevel, VecStack& active,  
+		 VecNode& level_list, NNMap& left, 
+		 NNMap& right, int& b, int& k, bool what_heur ) 
+    {
+
+      Num lev=level[w];	
+      
+      Node right_n=right[w];
+      Node left_n=left[w];
+      
+      //unlacing starts
+      if ( g->valid(right_n) ) {
+	if ( g->valid(left_n) ) {
+	  right.set(left_n, right_n);
+	  left.set(right_n, left_n);
+	} else {
+	  level_list[lev]=right_n;   
+	  left.set(right_n, INVALID);
+	} 
+      } else {
+	if ( g->valid(left_n) ) {
+	  right.set(left_n, INVALID);
+	} else { 
+	  level_list[lev]=INVALID;   
+	} 
+      } 
+      //unlacing ends
+		
+      if ( !g->valid(level_list[lev]) ) {
+	      
+	//gapping starts
+	for (int i=lev; i!=k ; ) {
+	  Node v=level_list[++i];
+	  while ( g->valid(v) ) {
+	    level.set(v,n);
+	    v=right[v];
+	  }
+	  level_list[i]=INVALID;
+	  if ( !what_heur ) {
+	    while ( !active[i].empty() ) {
+	      active[i].pop();    //FIXME: ezt szebben kene
+	    }
+	  }	     
+	}
+	
+	level.set(w,n);
+	b=lev-1;
+	k=b;
+	//gapping ends
+	
+      } else {
+	
+	if ( newlevel == n ) level.set(w,n); 
+	else {
+	  level.set(w,++newlevel);
+	  active[newlevel].push(w);
+	  if ( what_heur ) b=newlevel;
+	  if ( k < newlevel ) ++k;      //now k=newlevel
+	  Node first=level_list[newlevel];
+	  if ( g->valid(first) ) left.set(first,w);
+	  right.set(w,first);
+	  left.set(w,INVALID);
+	  level_list[newlevel]=w;
+	}
+      }
+      
+    } //relabel
+
+
+    template<typename MapGraphWrapper> 
+    class DistanceMap {
+    protected:
+      const MapGraphWrapper* g;
+      typename MapGraphWrapper::template NodeMap<int> dist; 
+    public:
+      DistanceMap(MapGraphWrapper& _g) : g(&_g), dist(*g, g->nodeNum()) { }
+      void set(const typename MapGraphWrapper::Node& n, int a) { 
+	dist.set(n, a); 
+      }
+      int operator[](const typename MapGraphWrapper::Node& n) 
+	{ return dist[n]; }
+//       int get(const typename MapGraphWrapper::Node& n) const { 
+// 	return dist[n]; }
+//       bool get(const typename MapGraphWrapper::Edge& e) const { 
+// 	return (dist.get(g->tail(e))<dist.get(g->head(e))); }
+      bool operator[](const typename MapGraphWrapper::Edge& e) const { 
+	return (dist[g->tail(e)]<dist[g->head(e)]); 
+      }
+    };
+    
+  };
+
+
+  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+  void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase0( flowEnum fe ) 
+  {
+      
+      int heur0=(int)(H0*n);  //time while running 'bound decrease' 
+      int heur1=(int)(H1*n);  //time while running 'highest label'
+      int heur=heur1;         //starting time interval (#of relabels)
+      int numrelabel=0;
+     
+      bool what_heur=1;       
+      //It is 0 in case 'bound decrease' and 1 in case 'highest label'
+
+      bool end=false;     
+      //Needed for 'bound decrease', true means no active nodes are above bound b.
+
+      int k=n-2;  //bound on the highest level under n containing a node
+      int b=k;    //bound on the highest level under n of an active node
+      
+      VecStack active(n);
+      
+      NNMap left(*g, INVALID);
+      NNMap right(*g, INVALID);
+      VecNode level_list(n,INVALID);
+      //List of the nodes in level i<n, set to n.
+
+      NodeIt v;
+      for(g->first(v); g->valid(v); g->next(v)) level.set(v,n);
+      //setting each node to level n
+      
+      switch ( fe ) {
+      case PREFLOW:
+	{
+	  //counting the excess
+	  NodeIt v;
+	  for(g->first(v); g->valid(v); g->next(v)) {
+	    Num exc=0;
+	  
+	    InEdgeIt e;
+	    for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e];
+	    OutEdgeIt f;
+	    for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f];
+	    
+	    excess.set(v,exc);	  
+	    
+	    //putting the active nodes into the stack
+	    int lev=level[v];
+	    if ( exc > 0 && lev < n && v != t ) active[lev].push(v);
+	  }
+	  break;
+	}
+      case GEN_FLOW:
+	{
+	  //Counting the excess of t
+	  Num exc=0;
+	  
+	  InEdgeIt e;
+	  for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e];
+	  OutEdgeIt f;
+	  for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f];
+	  
+	  excess.set(t,exc);	
+	  
+	  break;
+	}
+      default:
+	break;
+      }
+      
+      preflowPreproc( fe, active, level_list, left, right );
+      //End of preprocessing 
+      
+      
+      //Push/relabel on the highest level active nodes.
+      while ( true ) {
+	if ( b == 0 ) {
+	  if ( !what_heur && !end && k > 0 ) {
+	    b=k;
+	    end=true;
+	  } else break;
+	}
+	
+	if ( active[b].empty() ) --b; 
+	else {
+	  end=false;  
+	  Node w=active[b].top();
+	  active[b].pop();
+	  int newlevel=push(w,active);
+	  if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list, 
+				       left, right, b, k, what_heur);
+	  
+	  ++numrelabel; 
+	  if ( numrelabel >= heur ) {
+	    numrelabel=0;
+	    if ( what_heur ) {
+	      what_heur=0;
+	      heur=heur0;
+	      end=false;
+	    } else {
+	      what_heur=1;
+	      heur=heur1;
+	      b=k; 
+	    }
+	  }
+	} 
+      } 
+    }
+
+
+
+  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+  void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase1() 
+  {
+      
+      int k=n-2;  //bound on the highest level under n containing a node
+      int b=k;    //bound on the highest level under n of an active node
+      
+      VecStack active(n);
+      level.set(s,0);
+      std::queue<Node> bfs_queue;
+      bfs_queue.push(s);
+	    
+      while (!bfs_queue.empty()) {
+	
+	Node v=bfs_queue.front();	
+	bfs_queue.pop();
+	int l=level[v]+1;
+	      
+	InEdgeIt e;
+	for(g->first(e,v); g->valid(e); g->next(e)) {
+	  if ( (*capacity)[e] <= (*flow)[e] ) continue;
+	  Node u=g->tail(e);
+	  if ( level[u] >= n ) { 
+	    bfs_queue.push(u);
+	    level.set(u, l);
+	    if ( excess[u] > 0 ) active[l].push(u);
+	  }
+	}
+	
+	OutEdgeIt f;
+	for(g->first(f,v); g->valid(f); g->next(f)) {
+	  if ( 0 >= (*flow)[f] ) continue;
+	  Node u=g->head(f);
+	  if ( level[u] >= n ) { 
+	    bfs_queue.push(u);
+	    level.set(u, l);
+	    if ( excess[u] > 0 ) active[l].push(u);
+	  }
+	}
+      }
+      b=n-2;
+
+      while ( true ) {
+	
+	if ( b == 0 ) break;
+
+	if ( active[b].empty() ) --b; 
+	else {
+	  Node w=active[b].top();
+	  active[b].pop();
+	  int newlevel=push(w,active);	  
+
+	  //relabel
+	  if ( excess[w] > 0 ) {
+	    level.set(w,++newlevel);
+	    active[newlevel].push(w);
+	    b=newlevel;
+	  }
+	}  // if stack[b] is nonempty
+      } // while(true)
+    }
+
+
+
+  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+  bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath() 
+  {
+      ResGW res_graph(*g, *capacity, *flow);
+      bool _augment=false;
+      
+      //ReachedMap level(res_graph);
+      FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
+      BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
+      bfs.pushAndSetReached(s);
+	
+      typename ResGW::template NodeMap<ResGWEdge> pred(res_graph); 
+      pred.set(s, INVALID);
+      
+      typename ResGW::template NodeMap<Num> free(res_graph);
+	
+      //searching for augmenting path
+      while ( !bfs.finished() ) { 
+	ResGWOutEdgeIt e=bfs;
+	if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
+	  Node v=res_graph.tail(e);
+	  Node w=res_graph.head(e);
+	  pred.set(w, e);
+	  if (res_graph.valid(pred[v])) {
+	    free.set(w, std::min(free[v], res_graph.resCap(e)));
+	  } else {
+	    free.set(w, res_graph.resCap(e)); 
+	  }
+	  if (res_graph.head(e)==t) { _augment=true; break; }
+	}
+	
+	++bfs;
+      } //end of searching augmenting path
+
+      if (_augment) {
+	Node n=t;
+	Num augment_value=free[t];
+	while (res_graph.valid(pred[n])) { 
+	  ResGWEdge e=pred[n];
+	  res_graph.augment(e, augment_value); 
+	  n=res_graph.tail(e);
+	}
+      }
+
+      return _augment;
+    }
+
+
+
+
+
+
+
+
+
+  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+  template<typename MutableGraph> 
+  bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow() 
+  {      
+      typedef MutableGraph MG;
+      bool _augment=false;
+
+      ResGW res_graph(*g, *capacity, *flow);
+
+      //bfs for distances on the residual graph
+      //ReachedMap level(res_graph);
+      FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
+      BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
+      bfs.pushAndSetReached(s);
+      typename ResGW::template NodeMap<int> 
+	dist(res_graph); //filled up with 0's
+
+      //F will contain the physical copy of the residual graph
+      //with the set of edges which are on shortest paths
+      MG F;
+      typename ResGW::template NodeMap<typename MG::Node> 
+	res_graph_to_F(res_graph);
+      {
+	typename ResGW::NodeIt n;
+	for(res_graph.first(n); res_graph.valid(n); res_graph.next(n)) {
+	  res_graph_to_F.set(n, F.addNode());
+	}
+      }
+
+      typename MG::Node sF=res_graph_to_F[s];
+      typename MG::Node tF=res_graph_to_F[t];
+      typename MG::template EdgeMap<ResGWEdge> original_edge(F);
+      typename MG::template EdgeMap<Num> residual_capacity(F);
+
+      while ( !bfs.finished() ) { 
+	ResGWOutEdgeIt e=bfs;
+	if (res_graph.valid(e)) {
+	  if (bfs.isBNodeNewlyReached()) {
+	    dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
+	    typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)], res_graph_to_F[res_graph.head(e)]);
+	    original_edge.update();
+	    original_edge.set(f, e);
+	    residual_capacity.update();
+	    residual_capacity.set(f, res_graph.resCap(e));
+	  } else {
+	    if (dist[res_graph.head(e)]==(dist[res_graph.tail(e)]+1)) {
+	      typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)], res_graph_to_F[res_graph.head(e)]);
+	      original_edge.update();
+	      original_edge.set(f, e);
+	      residual_capacity.update();
+	      residual_capacity.set(f, res_graph.resCap(e));
+	    }
+	  }
+	}
+	++bfs;
+      } //computing distances from s in the residual graph
+
+      bool __augment=true;
+
+      while (__augment) {
+	__augment=false;
+	//computing blocking flow with dfs
+	DfsIterator< MG, typename MG::template NodeMap<bool> > dfs(F);
+	typename MG::template NodeMap<typename MG::Edge> pred(F);
+	pred.set(sF, INVALID);
+	//invalid iterators for sources
+
+	typename MG::template NodeMap<Num> free(F);
+
+	dfs.pushAndSetReached(sF);      
+	while (!dfs.finished()) {
+	  ++dfs;
+	  if (F.valid(/*typename MG::OutEdgeIt*/(dfs))) {
+	    if (dfs.isBNodeNewlyReached()) {
+	      typename MG::Node v=F.aNode(dfs);
+	      typename MG::Node w=F.bNode(dfs);
+	      pred.set(w, dfs);
+	      if (F.valid(pred[v])) {
+		free.set(w, std::min(free[v], residual_capacity[dfs]));
+	      } else {
+		free.set(w, residual_capacity[dfs]); 
+	      }
+	      if (w==tF) { 
+		__augment=true; 
+		_augment=true;
+		break; 
+	      }
+	      
+	    } else {
+	      F.erase(/*typename MG::OutEdgeIt*/(dfs));
+	    }
+	  } 
+	}
+
+	if (__augment) {
+	  typename MG::Node n=tF;
+	  Num augment_value=free[tF];
+	  while (F.valid(pred[n])) { 
+	    typename MG::Edge e=pred[n];
+	    res_graph.augment(original_edge[e], augment_value); 
+	    n=F.tail(e);
+	    if (residual_capacity[e]==augment_value) 
+	      F.erase(e); 
+	    else 
+	      residual_capacity.set(e, residual_capacity[e]-augment_value);
+	  }
+	}
+	
+      }
+            
+      return _augment;
+    }
+
+
+
+
+
+
+  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
+  bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow2() 
+  {
+      bool _augment=false;
+
+      ResGW res_graph(*g, *capacity, *flow);
+      
+      //ReachedMap level(res_graph);
+      FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
+      BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
+
+      bfs.pushAndSetReached(s);
+      DistanceMap<ResGW> dist(res_graph);
+      while ( !bfs.finished() ) { 
+ 	ResGWOutEdgeIt e=bfs;
+ 	if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
+ 	  dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
+ 	}
+	++bfs;
+      } //computing distances from s in the residual graph
+
+      //Subgraph containing the edges on some shortest paths
+      ConstMap<typename ResGW::Node, bool> true_map(true);
+      typedef SubGraphWrapper<ResGW, ConstMap<typename ResGW::Node, bool>, 
+	DistanceMap<ResGW> > FilterResGW;
+      FilterResGW filter_res_graph(res_graph, true_map, dist);
+
+      //Subgraph, which is able to delete edges which are already 
+      //met by the dfs
+      typename FilterResGW::template NodeMap<typename FilterResGW::OutEdgeIt> 
+ 	first_out_edges(filter_res_graph);
+      typename FilterResGW::NodeIt v;
+      for(filter_res_graph.first(v); filter_res_graph.valid(v); 
+ 	  filter_res_graph.next(v)) 
+      {
+ 	typename FilterResGW::OutEdgeIt e;
+ 	filter_res_graph.first(e, v);
+ 	first_out_edges.set(v, e);
+      }
+      typedef ErasingFirstGraphWrapper<FilterResGW, typename FilterResGW::
+	template NodeMap<typename FilterResGW::OutEdgeIt> > ErasingResGW;
+      ErasingResGW erasing_res_graph(filter_res_graph, first_out_edges);
+
+      bool __augment=true;
+
+      while (__augment) {
+
+ 	__augment=false;
+  	//computing blocking flow with dfs
+  	DfsIterator< ErasingResGW, 
+	  typename ErasingResGW::template NodeMap<bool> > 
+  	  dfs(erasing_res_graph);
+ 	typename ErasingResGW::
+	  template NodeMap<typename ErasingResGW::OutEdgeIt> 
+	  pred(erasing_res_graph); 
+ 	pred.set(s, INVALID);
+  	//invalid iterators for sources
+
+  	typename ErasingResGW::template NodeMap<Num> 
+	  free1(erasing_res_graph);
+
+ 	dfs.pushAndSetReached(
+	  typename ErasingResGW::Node(
+	    typename FilterResGW::Node(
+	      typename ResGW::Node(s)
+	      )
+	    )
+	  );
+ 	while (!dfs.finished()) {
+ 	  ++dfs;
+ 	  if (erasing_res_graph.valid(
+ 		typename ErasingResGW::OutEdgeIt(dfs))) 
+ 	  { 
+  	    if (dfs.isBNodeNewlyReached()) {
+	  
+ 	      typename ErasingResGW::Node v=erasing_res_graph.aNode(dfs);
+ 	      typename ErasingResGW::Node w=erasing_res_graph.bNode(dfs);
+
+ 	      pred.set(w, /*typename ErasingResGW::OutEdgeIt*/(dfs));
+ 	      if (erasing_res_graph.valid(pred[v])) {
+ 		free1.set(w, std::min(free1[v], res_graph.resCap(
+				       typename ErasingResGW::OutEdgeIt(dfs))));
+ 	      } else {
+ 		free1.set(w, res_graph.resCap(
+			   typename ErasingResGW::OutEdgeIt(dfs))); 
+ 	      }
+	      
+ 	      if (w==t) { 
+ 		__augment=true; 
+ 		_augment=true;
+ 		break; 
+ 	      }
+ 	    } else {
+ 	      erasing_res_graph.erase(dfs);
+	    }
+	  }
+	}	
+
+  	if (__augment) {
+   	  typename ErasingResGW::Node n=typename FilterResGW::Node(typename ResGW::Node(t));
+// 	  typename ResGW::NodeMap<Num> a(res_graph);
+// 	  typename ResGW::Node b;
+// 	  Num j=a[b];
+// 	  typename FilterResGW::NodeMap<Num> a1(filter_res_graph);
+// 	  typename FilterResGW::Node b1;
+// 	  Num j1=a1[b1];
+// 	  typename ErasingResGW::NodeMap<Num> a2(erasing_res_graph);
+// 	  typename ErasingResGW::Node b2;
+// 	  Num j2=a2[b2];
+ 	  Num augment_value=free1[n];
+ 	  while (erasing_res_graph.valid(pred[n])) { 
+ 	    typename ErasingResGW::OutEdgeIt e=pred[n];
+ 	    res_graph.augment(e, augment_value);
+ 	    n=erasing_res_graph.tail(e);
+ 	    if (res_graph.resCap(e)==0)
+ 	      erasing_res_graph.erase(e);
+	}
+      }
+      
+      } //while (__augment) 
+            
+      return _augment;
+    }
+
+
+
+
+} //namespace hugo
+
+#endif //HUGO_PREFLOW_H
+
+
+
+
diff -r 02b8ddcb207a -r 8c74de352f80 src/work/jacint/preflow.h
--- a/src/work/jacint/preflow.h	Thu Apr 29 16:26:01 2004 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1016 +0,0 @@
-// -*- C++ -*-
-
-/*
-Heuristics: 
- 2 phase
- gap
- list 'level_list' on the nodes on level i implemented by hand
- stack 'active' on the active nodes on level i
- runs heuristic 'highest label' for H1*n relabels
- runs heuristic 'bound decrease' for H0*n relabels, starts with 'highest label'
- 
-Parameters H0 and H1 are initialized to 20 and 1.
-
-Constructors:
-
-Preflow(Graph, Node, Node, CapMap, FlowMap, bool) : bool must be false if 
-     FlowMap is not constant zero, and should be true if it is
-
-Members:
-
-void run()
-
-Num flowValue() : returns the value of a maximum flow
-
-void minMinCut(CutMap& M) : sets M to the characteristic vector of the 
-     minimum min cut. M should be a map of bools initialized to false. ??Is it OK?
-
-void maxMinCut(CutMap& M) : sets M to the characteristic vector of the 
-     maximum min cut. M should be a map of bools initialized to false.
-
-void minCut(CutMap& M) : sets M to the characteristic vector of 
-     a min cut. M should be a map of bools initialized to false.
-
-*/
-
-#ifndef HUGO_PREFLOW_H
-#define HUGO_PREFLOW_H
-
-#define H0 20
-#define H1 1
-
-#include <vector>
-#include <queue>
-#include <stack>
-
-#include <graph_wrapper.h>
-#include <bfs_iterator.h>
-#include <invalid.h>
-#include <maps.h>
-#include <for_each_macros.h>
-
-
-namespace hugo {
-
-  template <typename Graph, typename Num, 
-	    typename CapMap=typename Graph::template EdgeMap<Num>, 
-            typename FlowMap=typename Graph::template EdgeMap<Num> >
-  class MaxFlow {
-    
-    typedef typename Graph::Node Node;
-    typedef typename Graph::NodeIt NodeIt;
-    typedef typename Graph::OutEdgeIt OutEdgeIt;
-    typedef typename Graph::InEdgeIt InEdgeIt;
-
-    typedef typename std::vector<std::stack<Node> > VecStack;
-    typedef typename Graph::template NodeMap<Node> NNMap;
-    typedef typename std::vector<Node> VecNode;
-
-    const Graph* g;
-    Node s;
-    Node t;
-    const CapMap* capacity;  
-    FlowMap* flow;
-    int n;      //the number of nodes of G
-    typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
-    typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
-    typedef typename ResGW::Edge ResGWEdge;
-    //typedef typename ResGW::template NodeMap<bool> ReachedMap;
-    typedef typename Graph::template NodeMap<int> ReachedMap;
-    ReachedMap level;
-    //level works as a bool map in augmenting path algorithms 
-    //and is used by bfs for storing reached information.
-    //In preflow, it shows levels of nodes.
-    //typename Graph::template NodeMap<int> level;    
-    typename Graph::template NodeMap<Num> excess; 
-
-  public:
- 
-    enum flowEnum{
-      ZERO_FLOW=0,
-      GEN_FLOW=1,
-      PREFLOW=2
-    };
-
-    MaxFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity, 
-	    FlowMap& _flow) :
-      g(&_G), s(_s), t(_t), capacity(&_capacity), 
-      flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0) {}
-
-    void run() {
-      preflow( ZERO_FLOW );
-    }
-    
-    void preflow( flowEnum fe ) {
-      preflowPhase0(fe);
-      preflowPhase1();
-    }
-
-    void preflowPhase0( flowEnum fe );
-
-    void preflowPhase1();
-
-    bool augmentOnShortestPath();
-
-    template<typename MutableGraph> bool augmentOnBlockingFlow();
-
-    bool augmentOnBlockingFlow2();
-
-    /// Returns the actual flow value.
-    /// More precisely, it returns the negative excess of s, thus 
-    /// this works also for preflows.
-    Num flowValue() { 
-      Num a=0;
-      FOR_EACH_INC_LOC(OutEdgeIt, e, *g, s) a+=(*flow)[e];
-      FOR_EACH_INC_LOC(InEdgeIt, e, *g, s) a-=(*flow)[e];
-      return a;
-    }
-
-    //should be used only between preflowPhase0 and preflowPhase1
-    template<typename _CutMap>
-    void actMinCut(_CutMap& M) {
-      NodeIt v;
-      for(g->first(v); g->valid(v); g->next(v)) 
-      if ( level[v] < n ) {
-	M.set(v,false);
-      } else {
-	M.set(v,true);
-      }
-    }
-
-
-
-    /*
-      Returns the minimum min cut, by a bfs from s in the residual graph.
-    */
-    template<typename _CutMap>
-    void minMinCut(_CutMap& M) {
-    
-      std::queue<Node> queue;
-      
-      M.set(s,true);      
-      queue.push(s);
-
-      while (!queue.empty()) {
-        Node w=queue.front();
-	queue.pop();
-
-	OutEdgeIt e;
-	for(g->first(e,w) ; g->valid(e); g->next(e)) {
-	  Node v=g->head(e);
-	  if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
-	    queue.push(v);
-	    M.set(v, true);
-	  }
-	} 
-
-	InEdgeIt f;
-	for(g->first(f,w) ; g->valid(f); g->next(f)) {
-	  Node v=g->tail(f);
-	  if (!M[v] && (*flow)[f] > 0 ) {
-	    queue.push(v);
-	    M.set(v, true);
-	  }
-	} 
-      }
-    }
-
-
-  
-    /*
-      Returns the maximum min cut, by a reverse bfs 
-      from t in the residual graph.
-    */
-    
-    template<typename _CutMap>
-    void maxMinCut(_CutMap& M) {
-
-      NodeIt v;
-      for(g->first(v) ; g->valid(v); g->next(v)) {
-	M.set(v, true);
-      }
-
-      std::queue<Node> queue;
-      
-      M.set(t,false);        
-      queue.push(t);
-
-      while (!queue.empty()) {
-        Node w=queue.front();
-	queue.pop();
-
-
-	InEdgeIt e;
-	for(g->first(e,w) ; g->valid(e); g->next(e)) {
-	  Node v=g->tail(e);
-	  if (M[v] && (*flow)[e] < (*capacity)[e] ) {
-	    queue.push(v);
-	    M.set(v, false);
-	  }
-	}
-	
-	OutEdgeIt f;
-	for(g->first(f,w) ; g->valid(f); g->next(f)) {
-	  Node v=g->head(f);
-	  if (M[v] && (*flow)[f] > 0 ) {
-	    queue.push(v);
-	    M.set(v, false);
-	  }
-	}
-      }
-    }
-
-
-    template<typename CutMap>
-    void minCut(CutMap& M) {
-      minMinCut(M);
-    }
-
-    void resetTarget(Node _t) {t=_t;}
-    void resetSource(Node _s) {s=_s;}
-   
-    void resetCap(const CapMap& _cap) {
-      capacity=&_cap;
-    }
-    
-    void resetFlow(FlowMap& _flow) {
-      flow=&_flow;
-    }
-
-
-  private:
-
-    int push(Node w, VecStack& active) {
-      
-      int lev=level[w];
-      Num exc=excess[w];
-      int newlevel=n;       //bound on the next level of w
-	  
-      OutEdgeIt e;
-      for(g->first(e,w); g->valid(e); g->next(e)) {
-	    
-	if ( (*flow)[e] >= (*capacity)[e] ) continue; 
-	Node v=g->head(e);            
-	    
-	if( lev > level[v] ) { //Push is allowed now
-	  
-	  if ( excess[v]<=0 && v!=t && v!=s ) {
-	    int lev_v=level[v];
-	    active[lev_v].push(v);
-	  }
-	  
-	  Num cap=(*capacity)[e];
-	  Num flo=(*flow)[e];
-	  Num remcap=cap-flo;
-	  
-	  if ( remcap >= exc ) { //A nonsaturating push.
-	    
-	    flow->set(e, flo+exc);
-	    excess.set(v, excess[v]+exc);
-	    exc=0;
-	    break; 
-	    
-	  } else { //A saturating push.
-	    flow->set(e, cap);
-	    excess.set(v, excess[v]+remcap);
-	    exc-=remcap;
-	  }
-	} else if ( newlevel > level[v] ) newlevel = level[v];
-      } //for out edges wv 
-      
-      if ( exc > 0 ) {	
-	InEdgeIt e;
-	for(g->first(e,w); g->valid(e); g->next(e)) {
-	  
-	  if( (*flow)[e] <= 0 ) continue; 
-	  Node v=g->tail(e); 
-	  
-	  if( lev > level[v] ) { //Push is allowed now
-	    
-	    if ( excess[v]<=0 && v!=t && v!=s ) {
-	      int lev_v=level[v];
-	      active[lev_v].push(v);
-	    }
-	    
-	    Num flo=(*flow)[e];
-	    
-	    if ( flo >= exc ) { //A nonsaturating push.
-	      
-	      flow->set(e, flo-exc);
-	      excess.set(v, excess[v]+exc);
-	      exc=0;
-	      break; 
-	    } else {  //A saturating push.
-	      
-	      excess.set(v, excess[v]+flo);
-	      exc-=flo;
-	      flow->set(e,0);
-	    }  
-	  } else if ( newlevel > level[v] ) newlevel = level[v];
-	} //for in edges vw
-	
-      } // if w still has excess after the out edge for cycle
-      
-      excess.set(w, exc);
-      
-      return newlevel;
-     }
-
-
-    void preflowPreproc ( flowEnum fe, VecStack& active, 
-			  VecNode& level_list, NNMap& left, NNMap& right ) {
-
-      std::queue<Node> bfs_queue;
-      
-      switch ( fe ) {
-      case ZERO_FLOW: 
-	{
-	  //Reverse_bfs from t, to find the starting level.
-	  level.set(t,0);
-	  bfs_queue.push(t);
-	
-	  while (!bfs_queue.empty()) {
-	    
-	    Node v=bfs_queue.front();	
-	    bfs_queue.pop();
-	    int l=level[v]+1;
-	    
-	    InEdgeIt e;
-	    for(g->first(e,v); g->valid(e); g->next(e)) {
-	      Node w=g->tail(e);
-	      if ( level[w] == n && w != s ) {
-		bfs_queue.push(w);
-		Node first=level_list[l];
-		if ( g->valid(first) ) left.set(first,w);
-		right.set(w,first);
-		level_list[l]=w;
-		level.set(w, l);
-	      }
-	    }
-	  }
-	  
-	  //the starting flow
-	  OutEdgeIt e;
-	  for(g->first(e,s); g->valid(e); g->next(e)) 
-	    {
-	      Num c=(*capacity)[e];
-	      if ( c <= 0 ) continue;
-	      Node w=g->head(e);
-	      if ( level[w] < n ) {	  
-		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
-		flow->set(e, c); 
-		excess.set(w, excess[w]+c);
-	      }
-	    }
-	  break;
-	}
-	
-      case GEN_FLOW:
-      case PREFLOW:
-	{
-	  //Reverse_bfs from t in the residual graph, 
-	  //to find the starting level.
-	  level.set(t,0);
-	  bfs_queue.push(t);
-	  
-	  while (!bfs_queue.empty()) {
-	    
-	    Node v=bfs_queue.front();	
-	    bfs_queue.pop();
-	    int l=level[v]+1;
-	    
-	    InEdgeIt e;
-	    for(g->first(e,v); g->valid(e); g->next(e)) {
-	      if ( (*capacity)[e] <= (*flow)[e] ) continue;
-	      Node w=g->tail(e);
-	      if ( level[w] == n && w != s ) {
-		bfs_queue.push(w);
-		Node first=level_list[l];
-		if ( g->valid(first) ) left.set(first,w);
-		right.set(w,first);
-		level_list[l]=w;
-		level.set(w, l);
-	      }
-	    }
-	    
-	    OutEdgeIt f;
-	    for(g->first(f,v); g->valid(f); g->next(f)) {
-	      if ( 0 >= (*flow)[f] ) continue;
-	      Node w=g->head(f);
-	      if ( level[w] == n && w != s ) {
-		bfs_queue.push(w);
-		Node first=level_list[l];
-		if ( g->valid(first) ) left.set(first,w);
-		right.set(w,first);
-		level_list[l]=w;
-		level.set(w, l);
-	      }
-	    }
-	  }
-	  
-	  
-	  //the starting flow
-	  OutEdgeIt e;
-	  for(g->first(e,s); g->valid(e); g->next(e)) 
-	    {
-	      Num rem=(*capacity)[e]-(*flow)[e];
-	      if ( rem <= 0 ) continue;
-	      Node w=g->head(e);
-	      if ( level[w] < n ) {	  
-		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
-		flow->set(e, (*capacity)[e]); 
-		excess.set(w, excess[w]+rem);
-	      }
-	    }
-	  
-	  InEdgeIt f;
-	  for(g->first(f,s); g->valid(f); g->next(f)) 
-	    {
-	      if ( (*flow)[f] <= 0 ) continue;
-	      Node w=g->tail(f);
-	      if ( level[w] < n ) {	  
-		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
-		excess.set(w, excess[w]+(*flow)[f]);
-		flow->set(f, 0); 
-	      }
-	    }  
-	  break;
-	} //case PREFLOW
-      }
-    } //preflowPreproc
-
-
-
-    void relabel(Node w, int newlevel, VecStack& active,  
-		 VecNode& level_list, NNMap& left, 
-		 NNMap& right, int& b, int& k, bool what_heur ) 
-    {
-
-      Num lev=level[w];	
-      
-      Node right_n=right[w];
-      Node left_n=left[w];
-      
-      //unlacing starts
-      if ( g->valid(right_n) ) {
-	if ( g->valid(left_n) ) {
-	  right.set(left_n, right_n);
-	  left.set(right_n, left_n);
-	} else {
-	  level_list[lev]=right_n;   
-	  left.set(right_n, INVALID);
-	} 
-      } else {
-	if ( g->valid(left_n) ) {
-	  right.set(left_n, INVALID);
-	} else { 
-	  level_list[lev]=INVALID;   
-	} 
-      } 
-      //unlacing ends
-		
-      if ( !g->valid(level_list[lev]) ) {
-	      
-	//gapping starts
-	for (int i=lev; i!=k ; ) {
-	  Node v=level_list[++i];
-	  while ( g->valid(v) ) {
-	    level.set(v,n);
-	    v=right[v];
-	  }
-	  level_list[i]=INVALID;
-	  if ( !what_heur ) {
-	    while ( !active[i].empty() ) {
-	      active[i].pop();    //FIXME: ezt szebben kene
-	    }
-	  }	     
-	}
-	
-	level.set(w,n);
-	b=lev-1;
-	k=b;
-	//gapping ends
-	
-      } else {
-	
-	if ( newlevel == n ) level.set(w,n); 
-	else {
-	  level.set(w,++newlevel);
-	  active[newlevel].push(w);
-	  if ( what_heur ) b=newlevel;
-	  if ( k < newlevel ) ++k;      //now k=newlevel
-	  Node first=level_list[newlevel];
-	  if ( g->valid(first) ) left.set(first,w);
-	  right.set(w,first);
-	  left.set(w,INVALID);
-	  level_list[newlevel]=w;
-	}
-      }
-      
-    } //relabel
-
-
-    template<typename MapGraphWrapper> 
-    class DistanceMap {
-    protected:
-      const MapGraphWrapper* g;
-      typename MapGraphWrapper::template NodeMap<int> dist; 
-    public:
-      DistanceMap(MapGraphWrapper& _g) : g(&_g), dist(*g, g->nodeNum()) { }
-      void set(const typename MapGraphWrapper::Node& n, int a) { 
-	dist.set(n, a); 
-      }
-      int operator[](const typename MapGraphWrapper::Node& n) 
-	{ return dist[n]; }
-//       int get(const typename MapGraphWrapper::Node& n) const { 
-// 	return dist[n]; }
-//       bool get(const typename MapGraphWrapper::Edge& e) const { 
-// 	return (dist.get(g->tail(e))<dist.get(g->head(e))); }
-      bool operator[](const typename MapGraphWrapper::Edge& e) const { 
-	return (dist[g->tail(e)]<dist[g->head(e)]); 
-      }
-    };
-    
-  };
-
-
-  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
-  void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase0( flowEnum fe ) 
-  {
-      
-      int heur0=(int)(H0*n);  //time while running 'bound decrease' 
-      int heur1=(int)(H1*n);  //time while running 'highest label'
-      int heur=heur1;         //starting time interval (#of relabels)
-      int numrelabel=0;
-     
-      bool what_heur=1;       
-      //It is 0 in case 'bound decrease' and 1 in case 'highest label'
-
-      bool end=false;     
-      //Needed for 'bound decrease', true means no active nodes are above bound b.
-
-      int k=n-2;  //bound on the highest level under n containing a node
-      int b=k;    //bound on the highest level under n of an active node
-      
-      VecStack active(n);
-      
-      NNMap left(*g, INVALID);
-      NNMap right(*g, INVALID);
-      VecNode level_list(n,INVALID);
-      //List of the nodes in level i<n, set to n.
-
-      NodeIt v;
-      for(g->first(v); g->valid(v); g->next(v)) level.set(v,n);
-      //setting each node to level n
-      
-      switch ( fe ) {
-      case PREFLOW:
-	{
-	  //counting the excess
-	  NodeIt v;
-	  for(g->first(v); g->valid(v); g->next(v)) {
-	    Num exc=0;
-	  
-	    InEdgeIt e;
-	    for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e];
-	    OutEdgeIt f;
-	    for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f];
-	    
-	    excess.set(v,exc);	  
-	    
-	    //putting the active nodes into the stack
-	    int lev=level[v];
-	    if ( exc > 0 && lev < n && v != t ) active[lev].push(v);
-	  }
-	  break;
-	}
-      case GEN_FLOW:
-	{
-	  //Counting the excess of t
-	  Num exc=0;
-	  
-	  InEdgeIt e;
-	  for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e];
-	  OutEdgeIt f;
-	  for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f];
-	  
-	  excess.set(t,exc);	
-	  
-	  break;
-	}
-      default:
-	break;
-      }
-      
-      preflowPreproc( fe, active, level_list, left, right );
-      //End of preprocessing 
-      
-      
-      //Push/relabel on the highest level active nodes.
-      while ( true ) {
-	if ( b == 0 ) {
-	  if ( !what_heur && !end && k > 0 ) {
-	    b=k;
-	    end=true;
-	  } else break;
-	}
-	
-	if ( active[b].empty() ) --b; 
-	else {
-	  end=false;  
-	  Node w=active[b].top();
-	  active[b].pop();
-	  int newlevel=push(w,active);
-	  if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list, 
-				       left, right, b, k, what_heur);
-	  
-	  ++numrelabel; 
-	  if ( numrelabel >= heur ) {
-	    numrelabel=0;
-	    if ( what_heur ) {
-	      what_heur=0;
-	      heur=heur0;
-	      end=false;
-	    } else {
-	      what_heur=1;
-	      heur=heur1;
-	      b=k; 
-	    }
-	  }
-	} 
-      } 
-    }
-
-
-
-  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
-  void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase1() 
-  {
-      
-      int k=n-2;  //bound on the highest level under n containing a node
-      int b=k;    //bound on the highest level under n of an active node
-      
-      VecStack active(n);
-      level.set(s,0);
-      std::queue<Node> bfs_queue;
-      bfs_queue.push(s);
-	    
-      while (!bfs_queue.empty()) {
-	
-	Node v=bfs_queue.front();	
-	bfs_queue.pop();
-	int l=level[v]+1;
-	      
-	InEdgeIt e;
-	for(g->first(e,v); g->valid(e); g->next(e)) {
-	  if ( (*capacity)[e] <= (*flow)[e] ) continue;
-	  Node u=g->tail(e);
-	  if ( level[u] >= n ) { 
-	    bfs_queue.push(u);
-	    level.set(u, l);
-	    if ( excess[u] > 0 ) active[l].push(u);
-	  }
-	}
-	
-	OutEdgeIt f;
-	for(g->first(f,v); g->valid(f); g->next(f)) {
-	  if ( 0 >= (*flow)[f] ) continue;
-	  Node u=g->head(f);
-	  if ( level[u] >= n ) { 
-	    bfs_queue.push(u);
-	    level.set(u, l);
-	    if ( excess[u] > 0 ) active[l].push(u);
-	  }
-	}
-      }
-      b=n-2;
-
-      while ( true ) {
-	
-	if ( b == 0 ) break;
-
-	if ( active[b].empty() ) --b; 
-	else {
-	  Node w=active[b].top();
-	  active[b].pop();
-	  int newlevel=push(w,active);	  
-
-	  //relabel
-	  if ( excess[w] > 0 ) {
-	    level.set(w,++newlevel);
-	    active[newlevel].push(w);
-	    b=newlevel;
-	  }
-	}  // if stack[b] is nonempty
-      } // while(true)
-    }
-
-
-
-  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
-  bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath() 
-  {
-      ResGW res_graph(*g, *capacity, *flow);
-      bool _augment=false;
-      
-      //ReachedMap level(res_graph);
-      FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
-      BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
-      bfs.pushAndSetReached(s);
-	
-      typename ResGW::template NodeMap<ResGWEdge> pred(res_graph); 
-      pred.set(s, INVALID);
-      
-      typename ResGW::template NodeMap<Num> free(res_graph);
-	
-      //searching for augmenting path
-      while ( !bfs.finished() ) { 
-	ResGWOutEdgeIt e=bfs;
-	if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
-	  Node v=res_graph.tail(e);
-	  Node w=res_graph.head(e);
-	  pred.set(w, e);
-	  if (res_graph.valid(pred[v])) {
-	    free.set(w, std::min(free[v], res_graph.resCap(e)));
-	  } else {
-	    free.set(w, res_graph.resCap(e)); 
-	  }
-	  if (res_graph.head(e)==t) { _augment=true; break; }
-	}
-	
-	++bfs;
-      } //end of searching augmenting path
-
-      if (_augment) {
-	Node n=t;
-	Num augment_value=free[t];
-	while (res_graph.valid(pred[n])) { 
-	  ResGWEdge e=pred[n];
-	  res_graph.augment(e, augment_value); 
-	  n=res_graph.tail(e);
-	}
-      }
-
-      return _augment;
-    }
-
-
-
-
-
-
-
-
-
-  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
-  template<typename MutableGraph> 
-  bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow() 
-  {      
-      typedef MutableGraph MG;
-      bool _augment=false;
-
-      ResGW res_graph(*g, *capacity, *flow);
-
-      //bfs for distances on the residual graph
-      //ReachedMap level(res_graph);
-      FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
-      BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
-      bfs.pushAndSetReached(s);
-      typename ResGW::template NodeMap<int> 
-	dist(res_graph); //filled up with 0's
-
-      //F will contain the physical copy of the residual graph
-      //with the set of edges which are on shortest paths
-      MG F;
-      typename ResGW::template NodeMap<typename MG::Node> 
-	res_graph_to_F(res_graph);
-      {
-	typename ResGW::NodeIt n;
-	for(res_graph.first(n); res_graph.valid(n); res_graph.next(n)) {
-	  res_graph_to_F.set(n, F.addNode());
-	}
-      }
-
-      typename MG::Node sF=res_graph_to_F[s];
-      typename MG::Node tF=res_graph_to_F[t];
-      typename MG::template EdgeMap<ResGWEdge> original_edge(F);
-      typename MG::template EdgeMap<Num> residual_capacity(F);
-
-      while ( !bfs.finished() ) { 
-	ResGWOutEdgeIt e=bfs;
-	if (res_graph.valid(e)) {
-	  if (bfs.isBNodeNewlyReached()) {
-	    dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
-	    typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)], res_graph_to_F[res_graph.head(e)]);
-	    original_edge.update();
-	    original_edge.set(f, e);
-	    residual_capacity.update();
-	    residual_capacity.set(f, res_graph.resCap(e));
-	  } else {
-	    if (dist[res_graph.head(e)]==(dist[res_graph.tail(e)]+1)) {
-	      typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)], res_graph_to_F[res_graph.head(e)]);
-	      original_edge.update();
-	      original_edge.set(f, e);
-	      residual_capacity.update();
-	      residual_capacity.set(f, res_graph.resCap(e));
-	    }
-	  }
-	}
-	++bfs;
-      } //computing distances from s in the residual graph
-
-      bool __augment=true;
-
-      while (__augment) {
-	__augment=false;
-	//computing blocking flow with dfs
-	DfsIterator< MG, typename MG::template NodeMap<bool> > dfs(F);
-	typename MG::template NodeMap<typename MG::Edge> pred(F);
-	pred.set(sF, INVALID);
-	//invalid iterators for sources
-
-	typename MG::template NodeMap<Num> free(F);
-
-	dfs.pushAndSetReached(sF);      
-	while (!dfs.finished()) {
-	  ++dfs;
-	  if (F.valid(/*typename MG::OutEdgeIt*/(dfs))) {
-	    if (dfs.isBNodeNewlyReached()) {
-	      typename MG::Node v=F.aNode(dfs);
-	      typename MG::Node w=F.bNode(dfs);
-	      pred.set(w, dfs);
-	      if (F.valid(pred[v])) {
-		free.set(w, std::min(free[v], residual_capacity[dfs]));
-	      } else {
-		free.set(w, residual_capacity[dfs]); 
-	      }
-	      if (w==tF) { 
-		__augment=true; 
-		_augment=true;
-		break; 
-	      }
-	      
-	    } else {
-	      F.erase(/*typename MG::OutEdgeIt*/(dfs));
-	    }
-	  } 
-	}
-
-	if (__augment) {
-	  typename MG::Node n=tF;
-	  Num augment_value=free[tF];
-	  while (F.valid(pred[n])) { 
-	    typename MG::Edge e=pred[n];
-	    res_graph.augment(original_edge[e], augment_value); 
-	    n=F.tail(e);
-	    if (residual_capacity[e]==augment_value) 
-	      F.erase(e); 
-	    else 
-	      residual_capacity.set(e, residual_capacity[e]-augment_value);
-	  }
-	}
-	
-      }
-            
-      return _augment;
-    }
-
-
-
-
-
-
-  template <typename Graph, typename Num, typename CapMap, typename FlowMap>
-  bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow2() 
-  {
-      bool _augment=false;
-
-      ResGW res_graph(*g, *capacity, *flow);
-      
-      //ReachedMap level(res_graph);
-      FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
-      BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
-
-      bfs.pushAndSetReached(s);
-      DistanceMap<ResGW> dist(res_graph);
-      while ( !bfs.finished() ) { 
- 	ResGWOutEdgeIt e=bfs;
- 	if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
- 	  dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
- 	}
-	++bfs;
-      } //computing distances from s in the residual graph
-
-      //Subgraph containing the edges on some shortest paths
-      ConstMap<typename ResGW::Node, bool> true_map(true);
-      typedef SubGraphWrapper<ResGW, ConstMap<typename ResGW::Node, bool>, 
-	DistanceMap<ResGW> > FilterResGW;
-      FilterResGW filter_res_graph(res_graph, true_map, dist);
-
-      //Subgraph, which is able to delete edges which are already 
-      //met by the dfs
-      typename FilterResGW::template NodeMap<typename FilterResGW::OutEdgeIt> 
- 	first_out_edges(filter_res_graph);
-      typename FilterResGW::NodeIt v;
-      for(filter_res_graph.first(v); filter_res_graph.valid(v); 
- 	  filter_res_graph.next(v)) 
-      {
- 	typename FilterResGW::OutEdgeIt e;
- 	filter_res_graph.first(e, v);
- 	first_out_edges.set(v, e);
-      }
-      typedef ErasingFirstGraphWrapper<FilterResGW, typename FilterResGW::
-	template NodeMap<typename FilterResGW::OutEdgeIt> > ErasingResGW;
-      ErasingResGW erasing_res_graph(filter_res_graph, first_out_edges);
-
-      bool __augment=true;
-
-      while (__augment) {
-
- 	__augment=false;
-  	//computing blocking flow with dfs
-  	DfsIterator< ErasingResGW, 
-	  typename ErasingResGW::template NodeMap<bool> > 
-  	  dfs(erasing_res_graph);
- 	typename ErasingResGW::
-	  template NodeMap<typename ErasingResGW::OutEdgeIt> 
-	  pred(erasing_res_graph); 
- 	pred.set(s, INVALID);
-  	//invalid iterators for sources
-
-  	typename ErasingResGW::template NodeMap<Num> 
-	  free1(erasing_res_graph);
-
- 	dfs.pushAndSetReached(
-	  typename ErasingResGW::Node(
-	    typename FilterResGW::Node(
-	      typename ResGW::Node(s)
-	      )
-	    )
-	  );
- 	while (!dfs.finished()) {
- 	  ++dfs;
- 	  if (erasing_res_graph.valid(
- 		typename ErasingResGW::OutEdgeIt(dfs))) 
- 	  { 
-  	    if (dfs.isBNodeNewlyReached()) {
-	  
- 	      typename ErasingResGW::Node v=erasing_res_graph.aNode(dfs);
- 	      typename ErasingResGW::Node w=erasing_res_graph.bNode(dfs);
-
- 	      pred.set(w, /*typename ErasingResGW::OutEdgeIt*/(dfs));
- 	      if (erasing_res_graph.valid(pred[v])) {
- 		free1.set(w, std::min(free1[v], res_graph.resCap(
-				       typename ErasingResGW::OutEdgeIt(dfs))));
- 	      } else {
- 		free1.set(w, res_graph.resCap(
-			   typename ErasingResGW::OutEdgeIt(dfs))); 
- 	      }
-	      
- 	      if (w==t) { 
- 		__augment=true; 
- 		_augment=true;
- 		break; 
- 	      }
- 	    } else {
- 	      erasing_res_graph.erase(dfs);
-	    }
-	  }
-	}	
-
-  	if (__augment) {
-   	  typename ErasingResGW::Node n=typename FilterResGW::Node(typename ResGW::Node(t));
-// 	  typename ResGW::NodeMap<Num> a(res_graph);
-// 	  typename ResGW::Node b;
-// 	  Num j=a[b];
-// 	  typename FilterResGW::NodeMap<Num> a1(filter_res_graph);
-// 	  typename FilterResGW::Node b1;
-// 	  Num j1=a1[b1];
-// 	  typename ErasingResGW::NodeMap<Num> a2(erasing_res_graph);
-// 	  typename ErasingResGW::Node b2;
-// 	  Num j2=a2[b2];
- 	  Num augment_value=free1[n];
- 	  while (erasing_res_graph.valid(pred[n])) { 
- 	    typename ErasingResGW::OutEdgeIt e=pred[n];
- 	    res_graph.augment(e, augment_value);
- 	    n=erasing_res_graph.tail(e);
- 	    if (res_graph.resCap(e)==0)
- 	      erasing_res_graph.erase(e);
-	}
-      }
-      
-      } //while (__augment) 
-            
-      return _augment;
-    }
-
-
-
-
-} //namespace hugo
-
-#endif //HUGO_PREFLOW_H
-
-
-
-