diff -r 571003783202 -r 9aca797b87e8 src/work/jacint/preflow_jgraph.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/jacint/preflow_jgraph.h	Thu Feb 26 11:38:51 2004 +0000
@@ -0,0 +1,536 @@
+// -*- C++ -*-
+/*
+preflow.h with 'j_graph interface'
+by jacint. 
+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 implemented by hand
+ 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 10.
+
+The best preflow I could ever write.
+
+The constructor runs the algorithm.
+
+Members:
+
+T maxFlow() : returns the value of a maximum flow
+
+T flowOnEdge(EdgeIt e) : for a fixed maximum flow x it returns x(e) 
+
+FlowMap Flow() : returns the fixed maximum flow x
+
+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.
+
+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 PREFLOW_H
+#define PREFLOW_H
+
+#define H0 20
+#define H1 1
+
+#include <vector>
+#include <queue>
+
+#include<iostream>
+
+#include <time_measure.h>
+
+namespace hugo {
+
+  template <typename Graph, typename T, 
+    typename FlowMap=typename Graph::EdgeMap<T>,
+    typename CapMap=typename Graph::EdgeMap<T> >
+  class preflow {
+    
+    typedef typename Graph::TrivNodeIt NodeIt;
+    typedef typename Graph::TrivEdgeIt EdgeIt;
+    typedef typename Graph::NodeIt EachNodeIt;
+    typedef typename Graph::OutEdgeIt OutEdgeIt;
+    typedef typename Graph::InEdgeIt InEdgeIt;
+    
+    Graph& G;
+    NodeIt s;
+    NodeIt t;
+    FlowMap flow;
+    CapMap& capacity;  
+    T value;
+
+  public:
+    double time;
+    preflow(Graph& _G, NodeIt _s, NodeIt _t, CapMap& _capacity ) :
+      G(_G), s(_s), t(_t), flow(_G, 0), capacity(_capacity)
+    {
+
+      bool phase=0;        //phase 0 is the 1st phase, phase 1 is the 2nd
+      int n=G.numNodes(); 
+      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)
+      bool what_heur=1;       
+      /*
+	what_heur 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 relabel=0;
+      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
+      
+      typename Graph::NodeMap<int> level(G,n);      
+      typename Graph::NodeMap<T> excess(G); 
+
+      std::vector<NodeIt> active(n);
+      typename Graph::NodeMap<NodeIt> next(G);
+      //Stack of the active nodes in level i < n.
+      //We use it in both phases.
+
+      typename Graph::NodeMap<NodeIt> left(G);
+      typename Graph::NodeMap<NodeIt> right(G);
+      std::vector<NodeIt> level_list(n);
+      /*
+	List of the nodes in level i<n.
+      */
+
+      /*Reverse_bfs from t, to find the starting level.*/
+      level.set(t,0);
+      std::queue<NodeIt> bfs_queue;
+      bfs_queue.push(t);
+
+      while (!bfs_queue.empty()) {
+
+	NodeIt v=bfs_queue.front();	
+	bfs_queue.pop();
+	int l=level.get(v)+1;
+
+	for(InEdgeIt e=G.firstIn(v); e; G.next(e)) {
+	  NodeIt w=G.tail(e);
+	  if ( level.get(w) == n && w != s ) {
+	    bfs_queue.push(w);
+	    NodeIt first=level_list[l];
+	    if ( first ) left.set(first,w);
+	    right.set(w,first);
+	    level_list[l]=w;
+	    level.set(w, l);
+	  }
+	}
+      }
+      
+      level.set(s,n);
+      
+
+      /* Starting flow. It is everywhere 0 at the moment. */     
+      for(OutEdgeIt e=G.firstOut(s); e; G.next(e)) 
+	{
+	  T c=capacity.get(e);
+	  if ( c == 0 ) continue;
+	  NodeIt w=G.head(e);
+	  if ( level.get(w) < n ) {	  
+	    if ( excess.get(w) == 0 && w!=t ) {
+	      next.set(w,active[level.get(w)]);
+	      active[level.get(w)]=w;
+	    }
+	    flow.set(e, c); 
+	    excess.set(w, excess.get(w)+c);
+	  }
+	}
+
+      /* 
+	 End of preprocessing 
+      */
+
+
+
+      /*
+	Push/relabel on the highest level active nodes.
+      */	
+      while ( true ) {
+	
+	if ( b == 0 ) {
+	  if ( phase ) break;
+	  
+	  if ( !what_heur && !end && k > 0 ) {
+	    b=k;
+	    end=true;
+	  } else {
+	    phase=1;
+	    time=currTime();
+	    level.set(s,0);
+	    std::queue<NodeIt> bfs_queue;
+	    bfs_queue.push(s);
+	    
+	    while (!bfs_queue.empty()) {
+	      
+	      NodeIt v=bfs_queue.front();	
+	      bfs_queue.pop();
+	      int l=level.get(v)+1;
+	      
+	      for(InEdgeIt e=G.firstIn(v); e; G.next(e)) {
+		if ( capacity.get(e) == flow.get(e) ) continue;
+		NodeIt u=G.tail(e);
+		if ( level.get(u) >= n ) { 
+		  bfs_queue.push(u);
+		  level.set(u, l);
+		  if ( excess.get(u) > 0 ) {
+		    next.set(u,active[l]);
+		    active[l]=u;
+		  }
+		}
+	      }
+	    
+	      for(OutEdgeIt e=G.firstOut(v); e; G.next(e)) {
+		if ( 0 == flow.get(e) ) continue;
+		NodeIt u=G.head(e);
+		if ( level.get(u) >= n ) { 
+		  bfs_queue.push(u);
+		  level.set(u, l);
+		  if ( excess.get(u) > 0 ) {
+		    next.set(u,active[l]);
+		    active[l]=u;
+		  }
+		}
+	      }
+	    }
+	    b=n-2;
+	    }
+	    
+	}
+	  
+	  
+	if ( !active[b]  ) --b; 
+	else {
+	  end=false;  
+
+	  NodeIt w=active[b];
+	  active[b]=next.get(w);
+	  int lev=level.get(w);
+	  T exc=excess.get(w);
+	  int newlevel=n;       //bound on the next level of w
+	  
+	  for(OutEdgeIt e=G.firstOut(w); e; G.next(e)) {
+	    
+	    if ( flow.get(e) == capacity.get(e) ) continue; 
+	    NodeIt v=G.head(e);            
+	    //e=wv	    
+	    
+	    if( lev > level.get(v) ) {      
+	      /*Push is allowed now*/
+	      
+	      if ( excess.get(v)==0 && v!=t && v!=s ) {
+		int lev_v=level.get(v);
+		next.set(v,active[lev_v]);
+		active[lev_v]=v;
+	      }
+	      
+	      T cap=capacity.get(e);
+	      T flo=flow.get(e);
+	      T remcap=cap-flo;
+	      
+	      if ( remcap >= exc ) {       
+		/*A nonsaturating push.*/
+		
+		flow.set(e, flo+exc);
+		excess.set(v, excess.get(v)+exc);
+		exc=0;
+		break; 
+		
+	      } else { 
+		/*A saturating push.*/
+		
+		flow.set(e, cap);
+		excess.set(v, excess.get(v)+remcap);
+		exc-=remcap;
+	      }
+	    } else if ( newlevel > level.get(v) ){
+	      newlevel = level.get(v);
+	    }	    
+	    
+	  } //for out edges wv 
+	
+	
+	if ( exc > 0 ) {	
+	  for( InEdgeIt e=G.firstIn(w); e; G.next(e)) {
+	    
+	    if( flow.get(e) == 0 ) continue; 
+	    NodeIt v=G.tail(e);  
+	    //e=vw
+	    
+	    if( lev > level.get(v) ) {  
+	      /*Push is allowed now*/
+	      
+	      if ( excess.get(v)==0 && v!=t && v!=s ) {
+		int lev_v=level.get(v);
+		next.set(v,active[lev_v]);
+		active[lev_v]=v;
+	      }
+	      
+	      T flo=flow.get(e);
+	      
+	      if ( flo >= exc ) { 
+		/*A nonsaturating push.*/
+		
+		flow.set(e, flo-exc);
+		excess.set(v, excess.get(v)+exc);
+		exc=0;
+		break; 
+	      } else {                                               
+/*A saturating push.*/
+		
+		excess.set(v, excess.get(v)+flo);
+		exc-=flo;
+		flow.set(e,0);
+	      }  
+	    } else if ( newlevel > level.get(v) ) {
+	      newlevel = level.get(v);
+	    }	    
+	  } //for in edges vw
+	  
+	} // if w still has excess after the out edge for cycle
+	
+	excess.set(w, exc);
+	 
+	/*
+	  Relabel
+	*/
+	
+
+	if ( exc > 0 ) {
+	  //now 'lev' is the old level of w
+	
+	  if ( phase ) {
+	    level.set(w,++newlevel);
+	    next.set(w,active[newlevel]);
+	    active[newlevel]=w;
+	    b=newlevel;
+	  } else {
+	    //unlacing starts
+	    NodeIt right_n=right.get(w);
+	    NodeIt left_n=left.get(w);
+
+	    if ( right_n ) {
+	      if ( left_n ) {
+		right.set(left_n, right_n);
+		left.set(right_n, left_n);
+	      } else {
+		level_list[lev]=right_n;   
+		left.set(right_n, NodeIt());
+	      } 
+	    } else {
+	      if ( left_n ) {
+		right.set(left_n, NodeIt());
+	      } else { 
+		level_list[lev]=NodeIt();   
+
+	      } 
+	    } 
+	    //unlacing ends
+		
+	    //gapping starts
+	    if ( !level_list[lev] ) {
+	      
+	      for (int i=lev; i!=k ; ) {
+		NodeIt v=level_list[++i];
+		while ( v ) {
+		  level.set(v,n);
+		  v=right.get(v);
+		}
+		level_list[i]=NodeIt();
+		if ( !what_heur ) active[i]=NodeIt();
+	      }	     
+
+	      level.set(w,n);
+	      b=lev-1;
+	      k=b;
+	      //gapping ends
+	    } else {
+	      
+	      if ( newlevel == n ) level.set(w,n); 
+	      else {
+		level.set(w,++newlevel);
+		next.set(w,active[newlevel]);
+		active[newlevel]=w;
+		if ( what_heur ) b=newlevel;
+		if ( k < newlevel ) ++k;
+		NodeIt first=level_list[newlevel];
+		if ( first ) left.set(first,w);
+		right.set(w,first);
+		left.set(w,NodeIt());
+		level_list[newlevel]=w;
+	      }
+	    }
+
+
+	    ++relabel; 
+	    if ( relabel >= heur ) {
+	      relabel=0;
+	      if ( what_heur ) {
+		what_heur=0;
+		heur=heur0;
+		end=false;
+	      } else {
+		what_heur=1;
+		heur=heur1;
+		b=k; 
+	      }
+	    }
+	  } //phase 0
+	  
+	  
+	} // if ( exc > 0 )
+	  
+	
+	}  // if stack[b] is nonempty
+	
+      } // while(true)
+
+
+      value = excess.get(t);
+      /*Max flow value.*/
+     
+    } //void run()
+
+
+
+
+
+    /*
+      Returns the maximum value of a flow.
+     */
+
+    T maxFlow() {
+      return value;
+    }
+
+
+
+    /*
+      For the maximum flow x found by the algorithm, 
+      it returns the flow value on edge e, i.e. x(e). 
+    */
+   
+    T flowOnEdge(EdgeIt e) {
+      return flow.get(e);
+    }
+
+
+
+    FlowMap Flow() {
+      return flow;
+      }
+
+
+    
+    void Flow(FlowMap& _flow ) {
+      for(EachNodeIt v=G.firstNode() ; v; G.next(v))
+	_flow.set(v,flow.get(v));
+      }
+    
+
+
+    /*
+      Returns the minimum min cut, by a bfs from s in the residual graph.
+    */
+   
+    template<typename _CutMap>
+    void minMinCut(_CutMap& M) {
+    
+      std::queue<NodeIt> queue;
+      
+      M.set(s,true);      
+      queue.push(s);
+
+      while (!queue.empty()) {
+        NodeIt w=queue.front();
+	queue.pop();
+
+	for(OutEdgeIt e=G.firstOut(w) ; e; G.next(e)) {
+	  NodeIt v=G.head(e);
+	  if (!M.get(v) && flow.get(e) < capacity.get(e) ) {
+	    queue.push(v);
+	    M.set(v, true);
+	  }
+	} 
+
+	for(InEdgeIt e=G.firstIn(w) ; e; G.next(e)) {
+	  NodeIt v=G.tail(e);
+	  if (!M.get(v) && flow.get(e) > 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) {
+    
+      std::queue<NodeIt> queue;
+      
+      M.set(t,true);        
+      queue.push(t);
+
+      while (!queue.empty()) {
+        NodeIt w=queue.front();
+	queue.pop();
+
+	for(InEdgeIt e=G.firstIn(w) ; e; G.next(e)) {
+	  NodeIt v=G.tail(e);
+	  if (!M.get(v) && flow.get(e) < capacity.get(e) ) {
+	    queue.push(v);
+	    M.set(v, true);
+	  }
+	}
+
+	for(OutEdgeIt e=G.firstOut(w) ; e; G.next(e)) {
+	  NodeIt v=G.head(e);
+	  if (!M.get(v) && flow.get(e) > 0 ) {
+	    queue.push(v);
+	    M.set(v, true);
+	  }
+	}
+      }
+
+      for(EachNodeIt v=G.firstNode() ; v; G.next(v)) {
+	M.set(v, !M.get(v));
+      }
+
+    }
+
+
+
+    template<typename CutMap>
+    void minCut(CutMap& M) {
+      minMinCut(M);
+    }
+
+
+  };
+}//namespace marci
+#endif 
+
+
+
+