src/work/edmonds_karp.h
author marci
Wed, 17 Mar 2004 13:33:13 +0000
changeset 191 efea403c9595
parent 175 ebccffe4d47b
child 193 84c19824322a
permissions -rw-r--r--
.
     1 // -*- c++ -*-
     2 #ifndef EDMONDS_KARP_H
     3 #define EDMONDS_KARP_H
     4 
     5 #include <algorithm>
     6 #include <list>
     7 #include <iterator>
     8 
     9 #include <bfs_iterator.h>
    10 #include <invalid.h>
    11 
    12 namespace hugo {
    13 
    14   template<typename Graph, typename Number, typename FlowMap, typename CapacityMap>
    15   class ResGraph {
    16   public:
    17     typedef typename Graph::Node Node;
    18     typedef typename Graph::NodeIt NodeIt;
    19   private:
    20     typedef typename Graph::SymEdgeIt OldSymEdgeIt;
    21     const Graph& G;
    22     FlowMap& flow;
    23     const CapacityMap& capacity;
    24   public:
    25     ResGraph(const Graph& _G, FlowMap& _flow, 
    26 	     const CapacityMap& _capacity) : 
    27       G(_G), flow(_flow), capacity(_capacity) { }
    28 
    29     class Edge; 
    30     class OutEdgeIt; 
    31     friend class Edge; 
    32     friend class OutEdgeIt; 
    33 
    34     class Edge {
    35       friend class ResGraph<Graph, Number, FlowMap, CapacityMap>;
    36     protected:
    37       const ResGraph<Graph, Number, FlowMap, CapacityMap>* resG;
    38       OldSymEdgeIt sym;
    39     public:
    40       Edge() { } 
    41       //Edge(const Edge& e) : resG(e.resG), sym(e.sym) { }
    42       Number free() const { 
    43 	if (resG->G.aNode(sym)==resG->G.tail(sym)) { 
    44 	  return (resG->capacity.get(sym)-resG->flow.get(sym)); 
    45 	} else { 
    46 	  return (resG->flow.get(sym)); 
    47 	}
    48       }
    49       bool valid() const { return sym.valid(); }
    50       void augment(Number a) const {
    51 	if (resG->G.aNode(sym)==resG->G.tail(sym)) { 
    52 	  resG->flow.set(sym, resG->flow.get(sym)+a);
    53 	  //resG->flow[sym]+=a;
    54 	} else { 
    55 	  resG->flow.set(sym, resG->flow.get(sym)-a);
    56 	  //resG->flow[sym]-=a;
    57 	}
    58       }
    59     };
    60 
    61     class OutEdgeIt : public Edge {
    62       friend class ResGraph<Graph, Number, FlowMap, CapacityMap>;
    63     public:
    64       OutEdgeIt() { }
    65       //OutEdgeIt(const OutEdgeIt& e) { resG=e.resG; sym=e.sym; }
    66     private:
    67       OutEdgeIt(const ResGraph<Graph, Number, FlowMap, CapacityMap>& _resG, Node v) { 
    68       	resG=&_resG;
    69 	sym=resG->G.template first<OldSymEdgeIt>(v);
    70 	while( sym.valid() && !(free()>0) ) { ++sym; }
    71       }
    72     public:
    73       OutEdgeIt& operator++() { 
    74 	++sym; 
    75 	while( sym.valid() && !(free()>0) ) { ++sym; }
    76 	return *this; 
    77       }
    78     };
    79 
    80     void /*getF*/first(OutEdgeIt& e, Node v) const { 
    81       e=OutEdgeIt(*this, v); 
    82     }
    83     void /*getF*/first(NodeIt& v) const { G./*getF*/first(v); }
    84     
    85     template< typename It >
    86     It first() const { 
    87       It e;      
    88       /*getF*/first(e);
    89       return e; 
    90     }
    91 
    92     template< typename It >
    93     It first(Node v) const { 
    94       It e;
    95       /*getF*/first(e, v);
    96       return e; 
    97     }
    98 
    99     Node tail(Edge e) const { return G.aNode(e.sym); }
   100     Node head(Edge e) const { return G.bNode(e.sym); }
   101 
   102     Node aNode(OutEdgeIt e) const { return G.aNode(e.sym); }
   103     Node bNode(OutEdgeIt e) const { return G.bNode(e.sym); }
   104 
   105     int id(Node v) const { return G.id(v); }
   106 
   107     template <typename S>
   108     class NodeMap {
   109       typename Graph::NodeMap<S> node_map; 
   110     public:
   111       NodeMap(const ResGraph<Graph, Number, FlowMap, CapacityMap>& _G) : node_map(_G.G) { }
   112       NodeMap(const ResGraph<Graph, Number, FlowMap, CapacityMap>& _G, S a) : node_map(_G.G, a) { }
   113       void set(Node nit, S a) { node_map.set(nit, a); }
   114       S get(Node nit) const { return node_map.get(nit); }
   115       S& operator[](Node nit) { return node_map[nit]; } 
   116       const S& operator[](Node nit) const { return node_map[nit]; } 
   117     };
   118 
   119   };
   120 
   121 
   122   template<typename Graph, typename Number, typename FlowMap, typename CapacityMap>
   123   class ResGraph2 {
   124   public:
   125     typedef typename Graph::Node Node;
   126     typedef typename Graph::NodeIt NodeIt;
   127   private:
   128     //typedef typename Graph::SymEdgeIt OldSymEdgeIt;
   129     typedef typename Graph::OutEdgeIt OldOutEdgeIt;
   130     typedef typename Graph::InEdgeIt OldInEdgeIt;
   131     
   132     const Graph& G;
   133     FlowMap& flow;
   134     const CapacityMap& capacity;
   135   public:
   136     ResGraph2(const Graph& _G, FlowMap& _flow, 
   137 	     const CapacityMap& _capacity) : 
   138       G(_G), flow(_flow), capacity(_capacity) { }
   139 
   140     class Edge; 
   141     class OutEdgeIt; 
   142     friend class Edge; 
   143     friend class OutEdgeIt; 
   144 
   145     class Edge {
   146       friend class ResGraph2<Graph, Number, FlowMap, CapacityMap>;
   147     protected:
   148       const ResGraph2<Graph, Number, FlowMap, CapacityMap>* resG;
   149       //OldSymEdgeIt sym;
   150       OldOutEdgeIt out;
   151       OldInEdgeIt in;
   152       bool out_or_in; //true, iff out
   153     public:
   154       Edge() : out_or_in(true) { } 
   155       Number free() const { 
   156 	if (out_or_in) { 
   157 	  return (resG->capacity.get(out)-resG->flow.get(out)); 
   158 	} else { 
   159 	  return (resG->flow.get(in)); 
   160 	}
   161       }
   162       bool valid() const { 
   163 	return out_or_in && out.valid() || in.valid(); }
   164       void augment(Number a) const {
   165 	if (out_or_in) { 
   166 	  resG->flow.set(out, resG->flow.get(out)+a);
   167 	} else { 
   168 	  resG->flow.set(in, resG->flow.get(in)-a);
   169 	}
   170       }
   171     };
   172 
   173     class OutEdgeIt : public Edge {
   174       friend class ResGraph2<Graph, Number, FlowMap, CapacityMap>;
   175     public:
   176       OutEdgeIt() { }
   177     private:
   178       OutEdgeIt(const ResGraph2<Graph, Number, FlowMap, CapacityMap>& _resG, Node v) { 
   179       	resG=&_resG;
   180 	out=resG->G.template first<OldOutEdgeIt>(v);
   181 	while( out.valid() && !(free()>0) ) { ++out; }
   182 	if (!out.valid()) {
   183 	  out_or_in=0;
   184 	  in=resG->G.template first<OldInEdgeIt>(v);
   185 	  while( in.valid() && !(free()>0) ) { ++in; }
   186 	}
   187       }
   188     public:
   189       OutEdgeIt& operator++() { 
   190 	if (out_or_in) {
   191 	  Node v=resG->G.aNode(out);
   192 	  ++out;
   193 	  while( out.valid() && !(free()>0) ) { ++out; }
   194 	  if (!out.valid()) {
   195 	    out_or_in=0;
   196 	    in=resG->G.template first<OldInEdgeIt>(v);
   197 	    while( in.valid() && !(free()>0) ) { ++in; }
   198 	  }
   199 	} else {
   200 	  ++in;
   201 	  while( in.valid() && !(free()>0) ) { ++in; } 
   202 	}
   203 	return *this; 
   204       }
   205     };
   206 
   207     void /*getF*/first(OutEdgeIt& e, Node v) const { 
   208       e=OutEdgeIt(*this, v); 
   209     }
   210     void /*getF*/first(NodeIt& v) const { G./*getF*/first(v); }
   211     
   212     template< typename It >
   213     It first() const { 
   214       It e;
   215       /*getF*/first(e);
   216       return e; 
   217     }
   218 
   219     template< typename It >
   220     It first(Node v) const { 
   221       It e;
   222       /*getF*/first(e, v);
   223       return e; 
   224     }
   225 
   226     Node tail(Edge e) const { 
   227       return ((e.out_or_in) ? G.aNode(e.out) : G.aNode(e.in)); }
   228     Node head(Edge e) const { 
   229       return ((e.out_or_in) ? G.bNode(e.out) : G.bNode(e.in)); }
   230 
   231     Node aNode(OutEdgeIt e) const { 
   232       return ((e.out_or_in) ? G.aNode(e.out) : G.aNode(e.in)); }
   233     Node bNode(OutEdgeIt e) const { 
   234       return ((e.out_or_in) ? G.bNode(e.out) : G.bNode(e.in)); }
   235 
   236     int id(Node v) const { return G.id(v); }
   237 
   238     template <typename S>
   239     class NodeMap {
   240       typename Graph::NodeMap<S> node_map; 
   241     public:
   242       NodeMap(const ResGraph2<Graph, Number, FlowMap, CapacityMap>& _G) : node_map(_G.G) { }
   243       NodeMap(const ResGraph2<Graph, Number, FlowMap, CapacityMap>& _G, S a) : node_map(_G.G, a) { }
   244       void set(Node nit, S a) { node_map.set(nit, a); }
   245       S get(Node nit) const { return node_map.get(nit); }
   246     };
   247   };
   248 
   249 
   250   template <typename Graph, typename Number, typename FlowMap, typename CapacityMap>
   251   class MaxFlow {
   252   public:
   253     typedef typename Graph::Node Node;
   254     typedef typename Graph::Edge Edge;
   255     typedef typename Graph::EdgeIt EdgeIt;
   256     typedef typename Graph::OutEdgeIt OutEdgeIt;
   257     typedef typename Graph::InEdgeIt InEdgeIt;
   258 
   259   private:
   260     const Graph* G;
   261     Node s;
   262     Node t;
   263     FlowMap* flow;
   264     const CapacityMap* capacity;
   265     typedef ResGraphWrapper<Graph, Number, FlowMap, CapacityMap > AugGraph;
   266     typedef typename AugGraph::OutEdgeIt AugOutEdgeIt;
   267     typedef typename AugGraph::Edge AugEdge;
   268 
   269   public:
   270     MaxFlow(const Graph& _G, Node _s, Node _t, FlowMap& _flow, const CapacityMap& _capacity) : 
   271       G(&_G), s(_s), t(_t), flow(&_flow), capacity(&_capacity) { }
   272     bool augmentOnShortestPath() {
   273       AugGraph res_graph(*G, *flow, *capacity);
   274       bool _augment=false;
   275       
   276       typedef typename AugGraph::NodeMap<bool> ReachedMap;
   277       BfsIterator5< AugGraph, /*AugOutEdgeIt,*/ ReachedMap > res_bfs(res_graph);
   278       res_bfs.pushAndSetReached(s);
   279 	
   280       typename AugGraph::NodeMap<AugEdge> pred(res_graph); 
   281       pred.set(s, AugEdge(INVALID));
   282       
   283       typename AugGraph::NodeMap<Number> free(res_graph);
   284 	
   285       //searching for augmenting path
   286       while ( !res_bfs.finished() ) { 
   287 	AugOutEdgeIt e=res_bfs;
   288 	if (res_graph.valid(e) && res_bfs.isBNodeNewlyReached()) {
   289 	  Node v=res_graph.tail(e);
   290 	  Node w=res_graph.head(e);
   291 	  pred.set(w, e);
   292 	  if (res_graph.valid(pred.get(v))) {
   293 	    free.set(w, std::min(free.get(v), res_graph.free(e)));
   294 	  } else {
   295 	    free.set(w, res_graph.free(e)); 
   296 	  }
   297 	  if (res_graph.head(e)==t) { _augment=true; break; }
   298 	}
   299 	
   300 	++res_bfs;
   301       } //end of searching augmenting path
   302 
   303       if (_augment) {
   304 	Node n=t;
   305 	Number augment_value=free.get(t);
   306 	while (res_graph.valid(pred.get(n))) { 
   307 	  AugEdge e=pred.get(n);
   308 	  res_graph.augment(e, augment_value); 
   309 	  n=res_graph.tail(e);
   310 	}
   311       }
   312 
   313       return _augment;
   314     }
   315 
   316     template<typename MutableGraph> bool augmentOnBlockingFlow() {      
   317       bool _augment=false;
   318 
   319       AugGraph res_graph(*G, *flow, *capacity);
   320 
   321       typedef typename AugGraph::NodeMap<bool> ReachedMap;
   322       BfsIterator4< AugGraph, AugOutEdgeIt, ReachedMap > bfs(res_graph);
   323 
   324       bfs.pushAndSetReached(s);
   325       typename AugGraph::NodeMap<int> dist(res_graph); //filled up with 0's
   326       while ( !bfs.finished() ) { 
   327 	AugOutEdgeIt e=bfs;
   328 	if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
   329 	  dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1);
   330 	}
   331 	
   332 	++bfs;
   333       } //computing distances from s in the residual graph
   334 
   335       MutableGraph F;
   336       typename AugGraph::NodeMap<typename MutableGraph::Node> 
   337 	res_graph_to_F(res_graph);
   338       for(typename AugGraph::NodeIt n=res_graph.template first<typename AugGraph::NodeIt>(); res_graph.valid(n); res_graph.next(n)) {
   339 	res_graph_to_F.set(n, F.addNode());
   340       }
   341       
   342       typename MutableGraph::Node sF=res_graph_to_F.get(s);
   343       typename MutableGraph::Node tF=res_graph_to_F.get(t);
   344 
   345       typename MutableGraph::EdgeMap<AugEdge> original_edge(F);
   346       typename MutableGraph::EdgeMap<Number> residual_capacity(F);
   347 
   348       //Making F to the graph containing the edges of the residual graph 
   349       //which are in some shortest paths
   350       for(typename AugGraph::EdgeIt e=res_graph.template first<typename AugGraph::EdgeIt>(); res_graph.valid(e); res_graph.next(e)) {
   351 	if (dist.get(res_graph.head(e))==dist.get(res_graph.tail(e))+1) {
   352 	  typename MutableGraph::Edge f=F.addEdge(res_graph_to_F.get(res_graph.tail(e)), res_graph_to_F.get(res_graph.head(e)));
   353 	  original_edge.update();
   354 	  original_edge.set(f, e);
   355 	  residual_capacity.update();
   356 	  residual_capacity.set(f, res_graph.free(e));
   357 	} 
   358       }
   359 
   360       bool __augment=true;
   361 
   362       while (__augment) {
   363 	__augment=false;
   364 	//computing blocking flow with dfs
   365 	typedef typename MutableGraph::NodeMap<bool> BlockingReachedMap;
   366 	DfsIterator4< MutableGraph, typename MutableGraph::OutEdgeIt, BlockingReachedMap > dfs(F);
   367 	typename MutableGraph::NodeMap<typename MutableGraph::Edge> pred(F);
   368 	pred.set(sF, typename MutableGraph::Edge(INVALID));
   369 	//invalid iterators for sources
   370 
   371 	typename MutableGraph::NodeMap<Number> free(F);
   372 
   373 	dfs.pushAndSetReached(sF);      
   374 	while (!dfs.finished()) {
   375 	  ++dfs;
   376 	  if (F.valid(typename MutableGraph::OutEdgeIt(dfs))) {
   377 	    if (dfs.isBNodeNewlyReached()) {
   378 	      typename MutableGraph::Node v=F.aNode(dfs);
   379 	      typename MutableGraph::Node w=F.bNode(dfs);
   380 	      pred.set(w, dfs);
   381 	      if (F.valid(pred.get(v))) {
   382 		free.set(w, std::min(free.get(v), residual_capacity.get(dfs)));
   383 	      } else {
   384 		free.set(w, residual_capacity.get(dfs)); 
   385 	      }
   386 	      if (w==tF) { 
   387 		__augment=true; 
   388 		_augment=true;
   389 		break; 
   390 	      }
   391 	      
   392 	    } else {
   393 	      F.erase(typename MutableGraph::OutEdgeIt(dfs));
   394 	    }
   395 	  } 
   396 	}
   397 
   398 	if (__augment) {
   399 	  typename MutableGraph::Node n=tF;
   400 	  Number augment_value=free.get(tF);
   401 	  while (F.valid(pred.get(n))) { 
   402 	    typename MutableGraph::Edge e=pred.get(n);
   403 	    res_graph.augment(original_edge.get(e), augment_value); 
   404 	    n=F.tail(e);
   405 	    if (residual_capacity.get(e)==augment_value) 
   406 	      F.erase(e); 
   407 	    else 
   408 	      residual_capacity.set(e, residual_capacity.get(e)-augment_value);
   409 	  }
   410 	}
   411 	
   412       }
   413             
   414       return _augment;
   415     }
   416     bool augmentOnBlockingFlow2() {
   417       bool _augment=false;
   418 
   419       //typedef ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap> EAugGraph;
   420       typedef FilterGraphWrapper< ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap> > EAugGraph;
   421       typedef typename EAugGraph::OutEdgeIt EAugOutEdgeIt;
   422       typedef typename EAugGraph::Edge EAugEdge;
   423 
   424       EAugGraph res_graph(*G, *flow, *capacity);
   425 
   426       //typedef typename EAugGraph::NodeMap<bool> ReachedMap;
   427       BfsIterator4< 
   428 	ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>, 
   429 	typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::OutEdgeIt, 
   430 	ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::NodeMap<bool> > bfs(res_graph);
   431       
   432       bfs.pushAndSetReached(s);
   433 
   434       typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::
   435 	NodeMap<int>& dist=res_graph.dist;
   436 
   437       while ( !bfs.finished() ) {
   438 	typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::OutEdgeIt e=bfs;
   439 	if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
   440 	  dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1);
   441 	}
   442 	++bfs;	
   443       } //computing distances from s in the residual graph
   444 
   445       bool __augment=true;
   446 
   447       while (__augment) {
   448 
   449 	__augment=false;
   450 	//computing blocking flow with dfs
   451 	typedef typename EAugGraph::NodeMap<bool> BlockingReachedMap;
   452 	DfsIterator4< EAugGraph, EAugOutEdgeIt, BlockingReachedMap > 
   453 	  dfs(res_graph);
   454 	typename EAugGraph::NodeMap<EAugEdge> pred(res_graph); 
   455 	pred.set(s, EAugEdge(INVALID));
   456 	//invalid iterators for sources
   457 
   458 	typename EAugGraph::NodeMap<Number> free(res_graph);
   459 
   460 	dfs.pushAndSetReached(s);
   461 	while (!dfs.finished()) {
   462 	  ++dfs;
   463 	  if (res_graph.valid(EAugOutEdgeIt(dfs))) { 
   464 	    if (dfs.isBNodeNewlyReached()) {
   465 	  
   466 	      typename EAugGraph::Node v=res_graph.aNode(dfs);
   467 	      typename EAugGraph::Node w=res_graph.bNode(dfs);
   468 
   469 	      pred.set(w, EAugOutEdgeIt(dfs));
   470 	      if (res_graph.valid(pred.get(v))) {
   471 		free.set(w, std::min(free.get(v), res_graph.free(dfs)));
   472 	      } else {
   473 		free.set(w, res_graph.free(dfs)); 
   474 	      }
   475 	      
   476 	      if (w==t) { 
   477 		__augment=true; 
   478 		_augment=true;
   479 		break; 
   480 	      }
   481 	    } else {
   482 	      res_graph.erase(dfs);
   483 	    }
   484 	  } 
   485 
   486 	}
   487 
   488 	if (__augment) {
   489 	  typename EAugGraph::Node n=t;
   490 	  Number augment_value=free.get(t);
   491 	  while (res_graph.valid(pred.get(n))) { 
   492 	    EAugEdge e=pred.get(n);
   493 	    res_graph.augment(e, augment_value);
   494 	    n=res_graph.tail(e);
   495 	    if (res_graph.free(e)==0)
   496 	      res_graph.erase(e);
   497 	  }
   498 	}
   499       
   500       }
   501             
   502       return _augment;
   503     }
   504     void run() {
   505       //int num_of_augmentations=0;
   506       while (augmentOnShortestPath()) { 
   507 	//while (augmentOnBlockingFlow<MutableGraph>()) { 
   508 	//std::cout << ++num_of_augmentations << " ";
   509 	//std::cout<<std::endl;
   510       } 
   511     }
   512     template<typename MutableGraph> void run() {
   513       //int num_of_augmentations=0;
   514       //while (augmentOnShortestPath()) { 
   515 	while (augmentOnBlockingFlow<MutableGraph>()) { 
   516 	//std::cout << ++num_of_augmentations << " ";
   517 	//std::cout<<std::endl;
   518       } 
   519     }
   520     Number flowValue() { 
   521       Number a=0;
   522       OutEdgeIt e;
   523       for(G->/*getF*/first(e, s); G->valid(e); G->next(e)) {
   524 	a+=flow->get(e);
   525       }
   526       return a;
   527     }
   528   };
   529 
   530   
   531 //   template <typename Graph, typename Number, typename FlowMap, typename CapacityMap>
   532 //   class MaxFlow2 {
   533 //   public:
   534 //     typedef typename Graph::Node Node;
   535 //     typedef typename Graph::Edge Edge;
   536 //     typedef typename Graph::EdgeIt EdgeIt;
   537 //     typedef typename Graph::OutEdgeIt OutEdgeIt;
   538 //     typedef typename Graph::InEdgeIt InEdgeIt;
   539 //   private:
   540 //     const Graph& G;
   541 //     std::list<Node>& S;
   542 //     std::list<Node>& T;
   543 //     FlowMap& flow;
   544 //     const CapacityMap& capacity;
   545 //     typedef ResGraphWrapper<Graph, Number, FlowMap, CapacityMap > AugGraph;
   546 //     typedef typename AugGraph::OutEdgeIt AugOutEdgeIt;
   547 //     typedef typename AugGraph::Edge AugEdge;
   548 //     typename Graph::NodeMap<bool> SMap;
   549 //     typename Graph::NodeMap<bool> TMap;
   550 //   public:
   551 //     MaxFlow2(const Graph& _G, std::list<Node>& _S, std::list<Node>& _T, FlowMap& _flow, const CapacityMap& _capacity) : G(_G), S(_S), T(_T), flow(_flow), capacity(_capacity), SMap(_G), TMap(_G) { 
   552 //       for(typename std::list<Node>::const_iterator i=S.begin(); 
   553 // 	  i!=S.end(); ++i) { 
   554 // 	SMap.set(*i, true); 
   555 //       }
   556 //       for (typename std::list<Node>::const_iterator i=T.begin(); 
   557 // 	   i!=T.end(); ++i) { 
   558 // 	TMap.set(*i, true); 
   559 //       }
   560 //     }
   561 //     bool augment() {
   562 //       AugGraph res_graph(G, flow, capacity);
   563 //       bool _augment=false;
   564 //       Node reached_t_node;
   565       
   566 //       typedef typename AugGraph::NodeMap<bool> ReachedMap;
   567 //       BfsIterator4< AugGraph, AugOutEdgeIt, ReachedMap > res_bfs(res_graph);
   568 //       for(typename std::list<Node>::const_iterator i=S.begin(); 
   569 // 	  i!=S.end(); ++i) {
   570 // 	res_bfs.pushAndSetReached(*i);
   571 //       }
   572 //       //res_bfs.pushAndSetReached(s);
   573 	
   574 //       typename AugGraph::NodeMap<AugEdge> pred(res_graph); 
   575 //       //filled up with invalid iterators
   576       
   577 //       typename AugGraph::NodeMap<Number> free(res_graph);
   578 	
   579 //       //searching for augmenting path
   580 //       while ( !res_bfs.finished() ) { 
   581 // 	AugOutEdgeIt e=/*AugOutEdgeIt*/(res_bfs);
   582 // 	if (e.valid() && res_bfs.isBNodeNewlyReached()) {
   583 // 	  Node v=res_graph.tail(e);
   584 // 	  Node w=res_graph.head(e);
   585 // 	  pred.set(w, e);
   586 // 	  if (pred.get(v).valid()) {
   587 // 	    free.set(w, std::min(free.get(v), e.free()));
   588 // 	  } else {
   589 // 	    free.set(w, e.free()); 
   590 // 	  }
   591 // 	  if (TMap.get(res_graph.head(e))) { 
   592 // 	    _augment=true; 
   593 // 	    reached_t_node=res_graph.head(e);
   594 // 	    break; 
   595 // 	  }
   596 // 	}
   597 	
   598 // 	++res_bfs;
   599 //       } //end of searching augmenting path
   600 
   601 //       if (_augment) {
   602 // 	Node n=reached_t_node;
   603 // 	Number augment_value=free.get(reached_t_node);
   604 // 	while (pred.get(n).valid()) { 
   605 // 	  AugEdge e=pred.get(n);
   606 // 	  e.augment(augment_value); 
   607 // 	  n=res_graph.tail(e);
   608 // 	}
   609 //       }
   610 
   611 //       return _augment;
   612 //     }
   613 //     void run() {
   614 //       while (augment()) { } 
   615 //     }
   616 //     Number flowValue() { 
   617 //       Number a=0;
   618 //       for(typename std::list<Node>::const_iterator i=S.begin(); 
   619 // 	  i!=S.end(); ++i) { 
   620 // 	for(OutEdgeIt e=G.template first<OutEdgeIt>(*i); e.valid(); ++e) {
   621 // 	  a+=flow.get(e);
   622 // 	}
   623 // 	for(InEdgeIt e=G.template first<InEdgeIt>(*i); e.valid(); ++e) {
   624 // 	  a-=flow.get(e);
   625 // 	}
   626 //       }
   627 //       return a;
   628 //     }
   629 //   };
   630 
   631 
   632 
   633 } // namespace hugo
   634 
   635 #endif //EDMONDS_KARP_H