# HG changeset patch
# User jacint
# Date 1082641885 0
# Node ID 5eceadf9316c5eaef4ca003b910e9209bc5db9f4
# Parent  dc9c19f4ca9ad301230031f3a3ebb4cd3745a857


diff -r dc9c19f4ca9a -r 5eceadf9316c src/work/jacint/preflowproba.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/jacint/preflowproba.h	Thu Apr 22 13:51:25 2004 +0000
@@ -0,0 +1,685 @@
+// -*- C++ -*-
+
+//run gyorsan tudna adni a minmincutot a 2 fazis elejen , ne vegyuk be konstruktorba egy cutmapet?
+//constzero jo igy?
+
+//majd marci megmondja betegyem-e bfs-t meg resgraphot
+
+/*
+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.
+
+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()
+
+T 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.
+
+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.
+
+FIXME reset
+
+*/
+
+#ifndef HUGO_PREFLOW_H
+#define HUGO_PREFLOW_H
+
+#define H0 20
+#define H1 1
+
+#include <vector>
+#include <queue>
+#include<graph_wrapper.h>
+
+namespace hugo {
+
+  template <typename Graph, typename T, 
+	    typename CapMap=typename Graph::EdgeMap<T>, 
+            typename FlowMap=typename Graph::EdgeMap<T> >
+  class Preflow {
+    
+    typedef typename Graph::Node Node;
+    typedef typename Graph::Edge Edge;
+    typedef typename Graph::NodeIt NodeIt;
+    typedef typename Graph::OutEdgeIt OutEdgeIt;
+    typedef typename Graph::InEdgeIt InEdgeIt;
+    
+    const Graph& G;
+    Node s;
+    Node t;
+    const CapMap& capacity;  
+    FlowMap& flow;
+    T value;
+    bool constzero;
+
+    typedef ResGraphWrapper<const Graph, T, CapMap, FlowMap> ResGW;
+    typedef typename ResGW::OutEdgeIt ResOutEdgeIt;
+    typedef typename ResGW::InEdgeIt ResInEdgeIt;
+    typedef typename ResGW::Edge ResEdge;
+ 
+  public:
+    Preflow(Graph& _G, Node _s, Node _t, CapMap& _capacity, 
+	    FlowMap& _flow, bool _constzero ) :
+      G(_G), s(_s), t(_t), capacity(_capacity), flow(_flow), constzero(_constzero) {}
+    
+    
+    void run() {
+
+      ResGW res_graph(G, capacity, flow);
+
+      value=0;                //for the subsequent runs
+
+      bool phase=0;        //phase 0 is the 1st phase, phase 1 is the 2nd
+      int n=G.nodeNum(); 
+      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<Node> active(n-1,INVALID);
+      typename Graph::NodeMap<Node> next(G,INVALID);
+      //Stack of the active nodes in level i < n.
+      //We use it in both phases.
+
+      typename Graph::NodeMap<Node> left(G,INVALID);
+      typename Graph::NodeMap<Node> right(G,INVALID);
+      std::vector<Node> level_list(n,INVALID);
+      /*
+	List of the nodes in level i<n.
+      */
+
+
+      if ( constzero ) {
+     
+	/*Reverse_bfs from t, to find the starting level.*/
+	level.set(t,0);
+	std::queue<Node> bfs_queue;
+	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)) 
+	{
+	  T c=capacity[e];
+	  if ( c == 0 ) continue;
+	  Node w=G.head(e);
+	  if ( level[w] < n ) {	  
+	    if ( excess[w] == 0 && w!=t ) {
+	      next.set(w,active[level[w]]);
+	      active[level[w]]=w;
+	    }
+	    flow.set(e, c); 
+	    excess.set(w, excess[w]+c);
+	  }
+	}
+      }
+      else 
+      {
+	
+	/*
+	  Reverse_bfs from t in the residual graph, 
+	  to find the starting level.
+	*/
+	level.set(t,0);
+	std::queue<Node> bfs_queue;
+	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);
+	    }
+	    }
+	}
+      
+	
+	/*
+	  Counting the excess
+	*/
+	NodeIt v;
+	for(G.first(v); G.valid(v); G.next(v)) {
+	  T 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[e];
+
+	  excess.set(v,exc);	  
+
+	  //putting the active nodes into the stack
+	  int lev=level[v];
+	  if ( exc > 0 && lev < n ) {
+	    next.set(v,active[lev]);
+	    active[lev]=v;
+	  }
+	}
+
+
+	//the starting flow
+	OutEdgeIt e;
+	for(G.first(e,s); G.valid(e); G.next(e)) 
+	{
+	  T rem=capacity[e]-flow[e];
+	  if ( rem == 0 ) continue;
+	  Node w=G.head(e);
+	  if ( level[w] < n ) {	  
+	    if ( excess[w] == 0 && w!=t ) {
+	      next.set(w,active[level[w]]);
+	      active[level[w]]=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.head(f);
+	  if ( level[w] < n ) {	  
+	    if ( excess[w] == 0 && w!=t ) {
+	      next.set(w,active[level[w]]);
+	      active[level[w]]=w;
+	    }
+	    excess.set(w, excess[w]+flow[f]);
+	    flow.set(f, 0); 
+	  }
+	}
+      }
+
+
+
+
+      /* 
+	 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;
+	    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;
+	      
+	      ResInEdgeIt e;
+	      for(res_graph.first(e,s); res_graph.valid(e); 
+		  res_graph.next(e)) {
+		Node u=res_graph.tail(e);
+		if ( level[u] >= n ) { 
+		  bfs_queue.push(u);
+		  level.set(u, l);
+		  if ( excess[u] > 0 ) {
+		    next.set(u,active[l]);
+		    active[l]=u;
+		  }
+		}
+	      }
+	      /*	      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 ) {
+		    next.set(u,active[l]);
+		    active[l]=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 ) {
+		    next.set(u,active[l]);
+		    active[l]=u;
+		  }
+		}
+		}*/
+	    }
+	    b=n-2;
+	    }
+	    
+	}
+	  
+	  
+	if ( !G.valid(active[b]) ) --b; 
+	else {
+	  end=false;  
+
+	  Node w=active[b];
+	  active[b]=next[w];
+	  int lev=level[w];
+	  T 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);            
+	    //e=wv	    
+	    
+	    if( lev > level[v] ) {      
+	      /*Push is allowed now*/
+	      
+	      if ( excess[v]==0 && v!=t && v!=s ) {
+		int lev_v=level[v];
+		next.set(v,active[lev_v]);
+		active[lev_v]=v;
+	      }
+	      
+	      T cap=capacity[e];
+	      T flo=flow[e];
+	      T 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);  
+	    //e=vw
+	    
+	    if( lev > level[v] ) {  
+	      /*Push is allowed now*/
+	      
+	      if ( excess[v]==0 && v!=t && v!=s ) {
+		int lev_v=level[v];
+		next.set(v,active[lev_v]);
+		active[lev_v]=v;
+	      }
+	      
+	      T 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);
+	 
+	/*
+	  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
+	    Node right_n=right[w];
+	    Node left_n=left[w];
+
+	    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 ) active[i]=INVALID;
+	      }	     
+
+	      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;      //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; 
+	    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[t];
+      /*Max flow value.*/
+     
+    } //void run()
+
+
+
+
+
+    /*
+      Returns the maximum value of a flow.
+     */
+
+    T flowValue() {
+      return value;
+    }
+
+
+    FlowMap Flow() {
+      return flow;
+      }
+
+
+    
+    void Flow(FlowMap& _flow ) {
+      NodeIt v;
+      for(G.first(v) ; G.valid(v); G.next(v))
+	_flow.set(v,flow[v]);
+    }
+
+
+
+    /*
+      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) {
+    
+      std::queue<Node> queue;
+      
+      M.set(t,true);        
+      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, true);
+	  }
+	}
+	
+	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, true);
+	  }
+	}
+      }
+
+      NodeIt v;
+      for(G.first(v) ; G.valid(v); G.next(v)) {
+	M.set(v, !M[v]);
+      }
+
+    }
+
+
+
+    template<typename CutMap>
+    void minCut(CutMap& M) {
+      minMinCut(M);
+    }
+
+    
+    void reset_target (Node _t) {t=_t;}
+    void reset_source (Node _s) {s=_s;}
+   
+    template<typename _CapMap>   
+    void reset_cap (_CapMap _cap) {capacity=_cap;}
+
+    template<typename _FlowMap>   
+    void reset_cap (_FlowMap _flow, bool _constzero) {
+      flow=_flow;
+      constzero=_constzero;
+    }
+
+
+
+  };
+
+} //namespace hugo
+
+#endif //PREFLOW_H
+
+
+
+