src/work/marci/augmenting_flow.h
author marci
Tue, 14 Sep 2004 10:09:24 +0000
changeset 849 cc3867a7d380
parent 775 e46a1f0623a0
child 854 baf0b6e40211
permissions -rw-r--r--
(none)
     1 // -*- C++ -*-
     2 #ifndef HUGO_AUGMENTING_FLOW_H
     3 #define HUGO_AUGMENTING_FLOW_H
     4 
     5 #include <vector>
     6 #include <queue>
     7 #include <stack>
     8 #include <iostream>
     9 
    10 #include <hugo/graph_wrapper.h>
    11 #include <bfs_dfs.h>
    12 #include <hugo/invalid.h>
    13 #include <hugo/maps.h>
    14 //#include <for_each_macros.h>
    15 
    16 /// \file
    17 /// \brief Maximum flow algorithms.
    18 /// \ingroup galgs
    19 
    20 namespace hugo {
    21 
    22   /// \addtogroup galgs
    23   /// @{                                                                                                                                        
    24   ///Maximum flow algorithms class.
    25 
    26   ///This class provides various algorithms for finding a flow of
    27   ///maximum value in a directed graph. The \e source node, the \e
    28   ///target node, the \e capacity of the edges and the \e starting \e
    29   ///flow value of the edges should be passed to the algorithm through the
    30   ///constructor. It is possible to change these quantities using the
    31   ///functions \ref resetSource, \ref resetTarget, \ref resetCap and
    32   ///\ref resetFlow. Before any subsequent runs of any algorithm of
    33   ///the class \ref resetFlow should be called. 
    34 
    35   ///After running an algorithm of the class, the actual flow value 
    36   ///can be obtained by calling \ref flowValue(). The minimum
    37   ///value cut can be written into a \c node map of \c bools by
    38   ///calling \ref minCut. (\ref minMinCut and \ref maxMinCut writes
    39   ///the inclusionwise minimum and maximum of the minimum value
    40   ///cuts, resp.)                                                                                                                               
    41   ///\param Graph The directed graph type the algorithm runs on.
    42   ///\param Num The number type of the capacities and the flow values.
    43   ///\param CapMap The capacity map type.
    44   ///\param FlowMap The flow map type.                                                                                                           
    45   ///\author Marton Makai, Jacint Szabo 
    46 //   template <typename Graph, typename Num,
    47 // 	    typename CapMap=typename Graph::template EdgeMap<Num>,
    48 //             typename FlowMap=typename Graph::template EdgeMap<Num> >
    49 //   class MaxFlow {
    50 //   protected:
    51 //     typedef typename Graph::Node Node;
    52 //     typedef typename Graph::NodeIt NodeIt;
    53 //     typedef typename Graph::EdgeIt EdgeIt;
    54 //     typedef typename Graph::OutEdgeIt OutEdgeIt;
    55 //     typedef typename Graph::InEdgeIt InEdgeIt;
    56 
    57 //     typedef typename std::vector<std::stack<Node> > VecStack;
    58 //     typedef typename Graph::template NodeMap<Node> NNMap;
    59 //     typedef typename std::vector<Node> VecNode;
    60 
    61 //     const Graph* g;
    62 //     Node s;
    63 //     Node t;
    64 //     const CapMap* capacity;
    65 //     FlowMap* flow;
    66 //     int n;      //the number of nodes of G
    67 //     typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;   
    68 //     //typedef ExpResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
    69 //     typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
    70 //     typedef typename ResGW::Edge ResGWEdge;
    71 //     //typedef typename ResGW::template NodeMap<bool> ReachedMap;
    72 //     typedef typename Graph::template NodeMap<int> ReachedMap;
    73 
    74 
    75 //     //level works as a bool map in augmenting path algorithms and is
    76 //     //used by bfs for storing reached information.  In preflow, it
    77 //     //shows the levels of nodes.     
    78 //     ReachedMap level;
    79 
    80 //     //excess is needed only in preflow
    81 //     typename Graph::template NodeMap<Num> excess;
    82 
    83 //     //fixme    
    84 // //   protected:
    85 //     //     MaxFlow() { }
    86 //     //     void set(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
    87 //     // 	     FlowMap& _flow)
    88 //     //       {
    89 //     // 	g=&_G;
    90 //     // 	s=_s;
    91 //     // 	t=_t;
    92 //     // 	capacity=&_capacity;
    93 //     // 	flow=&_flow;
    94 //     // 	n=_G.nodeNum;
    95 //     // 	level.set (_G); //kellene vmi ilyesmi fv
    96 //     // 	excess(_G,0); //itt is
    97 //     //       }
    98 
    99 //     // constants used for heuristics
   100 //     static const int H0=20;
   101 //     static const int H1=1;
   102 
   103 //   public:
   104 
   105 //     ///Indicates the property of the starting flow.
   106 
   107 //     ///Indicates the property of the starting flow. The meanings are as follows:
   108 //     ///- \c ZERO_FLOW: constant zero flow
   109 //     ///- \c GEN_FLOW: any flow, i.e. the sum of the in-flows equals to
   110 //     ///the sum of the out-flows in every node except the \e source and
   111 //     ///the \e target.
   112 //     ///- \c PRE_FLOW: any preflow, i.e. the sum of the in-flows is at 
   113 //     ///least the sum of the out-flows in every node except the \e source.
   114 //     ///- \c NO_FLOW: indicates an unspecified edge map. \ref flow will be 
   115 //     ///set to the constant zero flow in the beginning of the algorithm in this case.
   116 //     enum FlowEnum{
   117 //       ZERO_FLOW,
   118 //       GEN_FLOW,
   119 //       PRE_FLOW,
   120 //       NO_FLOW
   121 //     };
   122 
   123 //     enum StatusEnum {
   124 //       AFTER_NOTHING,
   125 //       AFTER_AUGMENTING,
   126 //       AFTER_FAST_AUGMENTING, 
   127 //       AFTER_PRE_FLOW_PHASE_1,      
   128 //       AFTER_PRE_FLOW_PHASE_2
   129 //     };
   130 
   131 //     /// Don not needle this flag only if necessary.
   132 //     StatusEnum status;
   133 // //     int number_of_augmentations;
   134 
   135 
   136 // //     template<typename IntMap>
   137 // //     class TrickyReachedMap {
   138 // //     protected:
   139 // //       IntMap* map;
   140 // //       int* number_of_augmentations;
   141 // //     public:
   142 // //       TrickyReachedMap(IntMap& _map, int& _number_of_augmentations) : 
   143 // // 	map(&_map), number_of_augmentations(&_number_of_augmentations) { }
   144 // //       void set(const Node& n, bool b) {
   145 // // 	if (b)
   146 // // 	  map->set(n, *number_of_augmentations);
   147 // // 	else 
   148 // // 	  map->set(n, *number_of_augmentations-1);
   149 // //       }
   150 // //       bool operator[](const Node& n) const { 
   151 // // 	return (*map)[n]==*number_of_augmentations; 
   152 // //       }
   153 // //     };
   154     
   155 //     MaxFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
   156 // 	    FlowMap& _flow) :
   157 //       g(&_G), s(_s), t(_t), capacity(&_capacity),
   158 //       flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0), 
   159 //       status(AFTER_NOTHING) { }
   160 
   161 //     ///Runs a maximum flow algorithm.
   162 
   163 //     ///Runs a preflow algorithm, which is the fastest maximum flow
   164 //     ///algorithm up-to-date. The default for \c fe is ZERO_FLOW.
   165 //     ///\pre The starting flow must be
   166 //     /// - a constant zero flow if \c fe is \c ZERO_FLOW,
   167 //     /// - an arbitary flow if \c fe is \c GEN_FLOW,
   168 //     /// - an arbitary preflow if \c fe is \c PRE_FLOW,
   169 //     /// - any map if \c fe is NO_FLOW.
   170 //     void run(FlowEnum fe=ZERO_FLOW) {
   171 //       preflow(fe);
   172 //     }
   173 
   174                                                                               
   175 //     ///Runs a preflow algorithm.  
   176 
   177 //     ///Runs a preflow algorithm. The preflow algorithms provide the
   178 //     ///fastest way to compute a maximum flow in a directed graph.
   179 //     ///\pre The starting flow must be
   180 //     /// - a constant zero flow if \c fe is \c ZERO_FLOW,
   181 //     /// - an arbitary flow if \c fe is \c GEN_FLOW,
   182 //     /// - an arbitary preflow if \c fe is \c PRE_FLOW,
   183 //     /// - any map if \c fe is NO_FLOW.
   184 //     void preflow(FlowEnum fe) {
   185 //       preflowPhase1(fe);
   186 //       preflowPhase2();
   187 //     }
   188 //     // Heuristics:
   189 //     //   2 phase
   190 //     //   gap
   191 //     //   list 'level_list' on the nodes on level i implemented by hand
   192 //     //   stack 'active' on the active nodes on level i                                                                                    
   193 //     //   runs heuristic 'highest label' for H1*n relabels
   194 //     //   runs heuristic 'bound decrease' for H0*n relabels, starts with 'highest label'
   195 //     //   Parameters H0 and H1 are initialized to 20 and 1.
   196 
   197 //     ///Runs the first phase of the preflow algorithm.
   198 
   199 //     ///The preflow algorithm consists of two phases, this method runs the
   200 //     ///first phase. After the first phase the maximum flow value and a
   201 //     ///minimum value cut can already be computed, though a maximum flow
   202 //     ///is net yet obtained. So after calling this method \ref flowValue
   203 //     ///and \ref actMinCut gives proper results.
   204 //     ///\warning: \ref minCut, \ref minMinCut and \ref maxMinCut do not
   205 //     ///give minimum value cuts unless calling \ref preflowPhase2.
   206 //     ///\pre The starting flow must be
   207 //     /// - a constant zero flow if \c fe is \c ZERO_FLOW,
   208 //     /// - an arbitary flow if \c fe is \c GEN_FLOW,
   209 //     /// - an arbitary preflow if \c fe is \c PRE_FLOW,
   210 //     /// - any map if \c fe is NO_FLOW.
   211 //     void preflowPhase1(FlowEnum fe);
   212 
   213 //     ///Runs the second phase of the preflow algorithm.
   214 
   215 //     ///The preflow algorithm consists of two phases, this method runs
   216 //     ///the second phase. After calling \ref preflowPhase1 and then
   217 //     ///\ref preflowPhase2 the methods \ref flowValue, \ref minCut,
   218 //     ///\ref minMinCut and \ref maxMinCut give proper results.
   219 //     ///\pre \ref preflowPhase1 must be called before.
   220 //     void preflowPhase2();
   221 
   222 //     /// Returns the maximum value of a flow.
   223 
   224 //     /// Returns the maximum value of a flow, by counting the 
   225 //     /// over-flow of the target node \ref t.
   226 //     /// It can be called already after running \ref preflowPhase1.
   227 //     Num flowValue() const {
   228 //       Num a=0;
   229 //       FOR_EACH_INC_LOC(InEdgeIt, e, *g, t) a+=(*flow)[e];
   230 //       FOR_EACH_INC_LOC(OutEdgeIt, e, *g, t) a-=(*flow)[e];
   231 //       return a;
   232 //       //marci figyu: excess[t] epp ezt adja preflow 1. fazisa utan   
   233 //     }
   234 
   235 //     ///Returns a minimum value cut after calling \ref preflowPhase1.
   236 
   237 //     ///After the first phase of the preflow algorithm the maximum flow
   238 //     ///value and a minimum value cut can already be computed. This
   239 //     ///method can be called after running \ref preflowPhase1 for
   240 //     ///obtaining a minimum value cut.
   241 //     /// \warning Gives proper result only right after calling \ref
   242 //     /// preflowPhase1.
   243 //     /// \todo We have to make some status variable which shows the
   244 //     /// actual state
   245 //     /// of the class. This enables us to determine which methods are valid
   246 //     /// for MinCut computation
   247 //     template<typename _CutMap>
   248 //     void actMinCut(_CutMap& M) const {
   249 //       NodeIt v;
   250 //       switch (status) {
   251 //       case AFTER_PRE_FLOW_PHASE_1:
   252 // 	for(g->first(v); g->valid(v); g->next(v)) {
   253 // 	  if (level[v] < n) {
   254 // 	    M.set(v, false);
   255 // 	  } else {
   256 // 	    M.set(v, true);
   257 // 	  }
   258 // 	}
   259 // 	break;
   260 //       case AFTER_PRE_FLOW_PHASE_2:
   261 //       case AFTER_NOTHING:
   262 //       case AFTER_AUGMENTING:
   263 //       case AFTER_FAST_AUGMENTING:
   264 // 	minMinCut(M);
   265 // 	break;
   266 // //       case AFTER_AUGMENTING:
   267 // // 	for(g->first(v); g->valid(v); g->next(v)) {
   268 // // 	  if (level[v]) {
   269 // // 	    M.set(v, true);
   270 // // 	  } else {
   271 // // 	    M.set(v, false);
   272 // // 	  }
   273 // // 	}
   274 // // 	break;
   275 // //       case AFTER_FAST_AUGMENTING:
   276 // // 	for(g->first(v); g->valid(v); g->next(v)) {
   277 // // 	  if (level[v]==number_of_augmentations) {
   278 // // 	    M.set(v, true);
   279 // // 	  } else {
   280 // // 	    M.set(v, false);
   281 // // 	  }
   282 // // 	}
   283 // // 	break;
   284 //       }
   285 //     }
   286 
   287 //     ///Returns the inclusionwise minimum of the minimum value cuts.
   288 
   289 //     ///Sets \c M to the characteristic vector of the minimum value cut
   290 //     ///which is inclusionwise minimum. It is computed by processing
   291 //     ///a bfs from the source node \c s in the residual graph.
   292 //     ///\pre M should be a node map of bools initialized to false.
   293 //     ///\pre \c flow must be a maximum flow.
   294 //     template<typename _CutMap>
   295 //     void minMinCut(_CutMap& M) const {
   296 //       std::queue<Node> queue;
   297 
   298 //       M.set(s,true);
   299 //       queue.push(s);
   300 
   301 //       while (!queue.empty()) {
   302 //         Node w=queue.front();
   303 // 	queue.pop();
   304 
   305 // 	OutEdgeIt e;
   306 // 	for(g->first(e,w) ; g->valid(e); g->next(e)) {
   307 // 	  Node v=g->head(e);
   308 // 	  if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
   309 // 	    queue.push(v);
   310 // 	    M.set(v, true);
   311 // 	  }
   312 // 	}
   313 
   314 // 	InEdgeIt f;
   315 // 	for(g->first(f,w) ; g->valid(f); g->next(f)) {
   316 // 	  Node v=g->tail(f);
   317 // 	  if (!M[v] && (*flow)[f] > 0 ) {
   318 // 	    queue.push(v);
   319 // 	    M.set(v, true);
   320 // 	  }
   321 // 	}
   322 //       }
   323 //     }
   324 
   325 //     ///Returns the inclusionwise maximum of the minimum value cuts.
   326 
   327 //     ///Sets \c M to the characteristic vector of the minimum value cut
   328 //     ///which is inclusionwise maximum. It is computed by processing a
   329 //     ///backward bfs from the target node \c t in the residual graph.
   330 //     ///\pre M should be a node map of bools initialized to false.
   331 //     ///\pre \c flow must be a maximum flow. 
   332 //     template<typename _CutMap>
   333 //     void maxMinCut(_CutMap& M) const {
   334 
   335 //       NodeIt v;
   336 //       for(g->first(v) ; g->valid(v); g->next(v)) {
   337 // 	M.set(v, true);
   338 //       }
   339 
   340 //       std::queue<Node> queue;
   341 
   342 //       M.set(t,false);
   343 //       queue.push(t);
   344 
   345 //       while (!queue.empty()) {
   346 //         Node w=queue.front();
   347 // 	queue.pop();
   348 
   349 // 	InEdgeIt e;
   350 // 	for(g->first(e,w) ; g->valid(e); g->next(e)) {
   351 // 	  Node v=g->tail(e);
   352 // 	  if (M[v] && (*flow)[e] < (*capacity)[e] ) {
   353 // 	    queue.push(v);
   354 // 	    M.set(v, false);
   355 // 	  }
   356 // 	}
   357 
   358 // 	OutEdgeIt f;
   359 // 	for(g->first(f,w) ; g->valid(f); g->next(f)) {
   360 // 	  Node v=g->head(f);
   361 // 	  if (M[v] && (*flow)[f] > 0 ) {
   362 // 	    queue.push(v);
   363 // 	    M.set(v, false);
   364 // 	  }
   365 // 	}
   366 //       }
   367 //     }
   368 
   369 //     ///Returns a minimum value cut.
   370 
   371 //     ///Sets \c M to the characteristic vector of a minimum value cut.
   372 //     ///\pre M should be a node map of bools initialized to false.
   373 //     ///\pre \c flow must be a maximum flow.    
   374 //     template<typename CutMap>
   375 //     void minCut(CutMap& M) const { minMinCut(M); }
   376 
   377 //     ///Resets the source node to \c _s.
   378 
   379 //     ///Resets the source node to \c _s.
   380 //     /// 
   381 //     void resetSource(Node _s) { s=_s; status=AFTER_NOTHING; }
   382 
   383 //     ///Resets the target node to \c _t.
   384 
   385 //     ///Resets the target node to \c _t.
   386 //     ///
   387 //     void resetTarget(Node _t) { t=_t; status=AFTER_NOTHING; }
   388 
   389 //     /// Resets the edge map of the capacities to _cap.
   390 
   391 //     /// Resets the edge map of the capacities to _cap.
   392 //     /// 
   393 //     void resetCap(const CapMap& _cap) { capacity=&_cap; status=AFTER_NOTHING; }
   394 
   395 //     /// Resets the edge map of the flows to _flow.
   396 
   397 //     /// Resets the edge map of the flows to _flow.
   398 //     /// 
   399 //     void resetFlow(FlowMap& _flow) { flow=&_flow; status=AFTER_NOTHING; }
   400 
   401 
   402 //   private:
   403 
   404 //     int push(Node w, VecStack& active) {
   405 
   406 //       int lev=level[w];
   407 //       Num exc=excess[w];
   408 //       int newlevel=n;       //bound on the next level of w
   409 
   410 //       OutEdgeIt e;
   411 //       for(g->first(e,w); g->valid(e); g->next(e)) {
   412 
   413 // 	if ( (*flow)[e] >= (*capacity)[e] ) continue;
   414 // 	Node v=g->head(e);
   415 
   416 // 	if( lev > level[v] ) { //Push is allowed now
   417 
   418 // 	  if ( excess[v]<=0 && v!=t && v!=s ) {
   419 // 	    int lev_v=level[v];
   420 // 	    active[lev_v].push(v);
   421 // 	  }
   422 
   423 // 	  Num cap=(*capacity)[e];
   424 // 	  Num flo=(*flow)[e];
   425 // 	  Num remcap=cap-flo;
   426 
   427 // 	  if ( remcap >= exc ) { //A nonsaturating push.
   428 
   429 // 	    flow->set(e, flo+exc);
   430 // 	    excess.set(v, excess[v]+exc);
   431 // 	    exc=0;
   432 // 	    break;
   433 
   434 // 	  } else { //A saturating push.
   435 // 	    flow->set(e, cap);
   436 // 	    excess.set(v, excess[v]+remcap);
   437 // 	    exc-=remcap;
   438 // 	  }
   439 // 	} else if ( newlevel > level[v] ) newlevel = level[v];
   440 //       } //for out edges wv
   441 
   442 //       if ( exc > 0 ) {
   443 // 	InEdgeIt e;
   444 // 	for(g->first(e,w); g->valid(e); g->next(e)) {
   445 
   446 // 	  if( (*flow)[e] <= 0 ) continue;
   447 // 	  Node v=g->tail(e);
   448 
   449 // 	  if( lev > level[v] ) { //Push is allowed now
   450 
   451 // 	    if ( excess[v]<=0 && v!=t && v!=s ) {
   452 // 	      int lev_v=level[v];
   453 // 	      active[lev_v].push(v);
   454 // 	    }
   455 
   456 // 	    Num flo=(*flow)[e];
   457 
   458 // 	    if ( flo >= exc ) { //A nonsaturating push.
   459 
   460 // 	      flow->set(e, flo-exc);
   461 // 	      excess.set(v, excess[v]+exc);
   462 // 	      exc=0;
   463 // 	      break;
   464 // 	    } else {  //A saturating push.
   465 
   466 // 	      excess.set(v, excess[v]+flo);
   467 // 	      exc-=flo;
   468 // 	      flow->set(e,0);
   469 // 	    }
   470 // 	  } else if ( newlevel > level[v] ) newlevel = level[v];
   471 // 	} //for in edges vw
   472 
   473 //       } // if w still has excess after the out edge for cycle
   474 
   475 //       excess.set(w, exc);
   476 
   477 //       return newlevel;
   478 //     }
   479 
   480 
   481 //     void preflowPreproc(FlowEnum fe, VecStack& active,
   482 // 			VecNode& level_list, NNMap& left, NNMap& right)
   483 //     {
   484 //       std::queue<Node> bfs_queue;
   485 
   486 //       switch (fe) {
   487 //       case NO_FLOW:   //flow is already set to const zero in this case
   488 //       case ZERO_FLOW:
   489 // 	{
   490 // 	  //Reverse_bfs from t, to find the starting level.
   491 // 	  level.set(t,0);
   492 // 	  bfs_queue.push(t);
   493 
   494 // 	  while (!bfs_queue.empty()) {
   495 
   496 // 	    Node v=bfs_queue.front();
   497 // 	    bfs_queue.pop();
   498 // 	    int l=level[v]+1;
   499 
   500 // 	    InEdgeIt e;
   501 // 	    for(g->first(e,v); g->valid(e); g->next(e)) {
   502 // 	      Node w=g->tail(e);
   503 // 	      if ( level[w] == n && w != s ) {
   504 // 		bfs_queue.push(w);
   505 // 		Node first=level_list[l];
   506 // 		if ( g->valid(first) ) left.set(first,w);
   507 // 		right.set(w,first);
   508 // 		level_list[l]=w;
   509 // 		level.set(w, l);
   510 // 	      }
   511 // 	    }
   512 // 	  }
   513 
   514 // 	  //the starting flow
   515 // 	  OutEdgeIt e;
   516 // 	  for(g->first(e,s); g->valid(e); g->next(e))
   517 // 	    {
   518 // 	      Num c=(*capacity)[e];
   519 // 	      if ( c <= 0 ) continue;
   520 // 	      Node w=g->head(e);
   521 // 	      if ( level[w] < n ) {
   522 // 		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
   523 // 		flow->set(e, c);
   524 // 		excess.set(w, excess[w]+c);
   525 // 	      }
   526 // 	    }
   527 // 	  break;
   528 // 	}
   529 
   530 //       case GEN_FLOW:
   531 //       case PRE_FLOW:
   532 // 	{
   533 // 	  //Reverse_bfs from t in the residual graph,
   534 // 	  //to find the starting level.
   535 // 	  level.set(t,0);
   536 // 	  bfs_queue.push(t);
   537 
   538 // 	  while (!bfs_queue.empty()) {
   539 
   540 // 	    Node v=bfs_queue.front();
   541 // 	    bfs_queue.pop();
   542 // 	    int l=level[v]+1;
   543 
   544 // 	    InEdgeIt e;
   545 // 	    for(g->first(e,v); g->valid(e); g->next(e)) {
   546 // 	      if ( (*capacity)[e] <= (*flow)[e] ) continue;
   547 // 	      Node w=g->tail(e);
   548 // 	      if ( level[w] == n && w != s ) {
   549 // 		bfs_queue.push(w);
   550 // 		Node first=level_list[l];
   551 // 		if ( g->valid(first) ) left.set(first,w);
   552 // 		right.set(w,first);
   553 // 		level_list[l]=w;
   554 // 		level.set(w, l);
   555 // 	      }
   556 // 	    }
   557 
   558 // 	    OutEdgeIt f;
   559 // 	    for(g->first(f,v); g->valid(f); g->next(f)) {
   560 // 	      if ( 0 >= (*flow)[f] ) continue;
   561 // 	      Node w=g->head(f);
   562 // 	      if ( level[w] == n && w != s ) {
   563 // 		bfs_queue.push(w);
   564 // 		Node first=level_list[l];
   565 // 		if ( g->valid(first) ) left.set(first,w);
   566 // 		right.set(w,first);
   567 // 		level_list[l]=w;
   568 // 		level.set(w, l);
   569 // 	      }
   570 // 	    }
   571 // 	  }
   572 
   573 
   574 // 	  //the starting flow
   575 // 	  OutEdgeIt e;
   576 // 	  for(g->first(e,s); g->valid(e); g->next(e))
   577 // 	    {
   578 // 	      Num rem=(*capacity)[e]-(*flow)[e];
   579 // 	      if ( rem <= 0 ) continue;
   580 // 	      Node w=g->head(e);
   581 // 	      if ( level[w] < n ) {
   582 // 		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
   583 // 		flow->set(e, (*capacity)[e]);
   584 // 		excess.set(w, excess[w]+rem);
   585 // 	      }
   586 // 	    }
   587 
   588 // 	  InEdgeIt f;
   589 // 	  for(g->first(f,s); g->valid(f); g->next(f))
   590 // 	    {
   591 // 	      if ( (*flow)[f] <= 0 ) continue;
   592 // 	      Node w=g->tail(f);
   593 // 	      if ( level[w] < n ) {
   594 // 		if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
   595 // 		excess.set(w, excess[w]+(*flow)[f]);
   596 // 		flow->set(f, 0);
   597 // 	      }
   598 // 	    }
   599 // 	  break;
   600 // 	} //case PRE_FLOW
   601 //       }
   602 //     } //preflowPreproc
   603 
   604 
   605 
   606 //     void relabel(Node w, int newlevel, VecStack& active,
   607 // 		 VecNode& level_list, NNMap& left,
   608 // 		 NNMap& right, int& b, int& k, bool what_heur )
   609 //     {
   610 
   611 //       //FIXME jacint: ez mitol num
   612 // //      Num lev=level[w];
   613 //       int lev=level[w];
   614 
   615 //       Node right_n=right[w];
   616 //       Node left_n=left[w];
   617 
   618 //       //unlacing starts
   619 //       if ( g->valid(right_n) ) {
   620 // 	if ( g->valid(left_n) ) {
   621 // 	  right.set(left_n, right_n);
   622 // 	  left.set(right_n, left_n);
   623 // 	} else {
   624 // 	  level_list[lev]=right_n;
   625 // 	  left.set(right_n, INVALID);
   626 // 	}
   627 //       } else {
   628 // 	if ( g->valid(left_n) ) {
   629 // 	  right.set(left_n, INVALID);
   630 // 	} else {
   631 // 	  level_list[lev]=INVALID;
   632 // 	}
   633 //       }
   634 //       //unlacing ends
   635 
   636 //       if ( !g->valid(level_list[lev]) ) {
   637 
   638 // 	//gapping starts
   639 // 	for (int i=lev; i!=k ; ) {
   640 // 	  Node v=level_list[++i];
   641 // 	  while ( g->valid(v) ) {
   642 // 	    level.set(v,n);
   643 // 	    v=right[v];
   644 // 	  }
   645 // 	  level_list[i]=INVALID;
   646 // 	  if ( !what_heur ) {
   647 // 	    while ( !active[i].empty() ) {
   648 // 	      active[i].pop();    //FIXME: ezt szebben kene
   649 // 	    }
   650 // 	  }
   651 // 	}
   652 
   653 // 	level.set(w,n);
   654 // 	b=lev-1;
   655 // 	k=b;
   656 // 	//gapping ends
   657 
   658 //       } else {
   659 
   660 // 	if ( newlevel == n ) level.set(w,n);
   661 // 	else {
   662 // 	  level.set(w,++newlevel);
   663 // 	  active[newlevel].push(w);
   664 // 	  if ( what_heur ) b=newlevel;
   665 // 	  if ( k < newlevel ) ++k;      //now k=newlevel
   666 // 	  Node first=level_list[newlevel];
   667 // 	  if ( g->valid(first) ) left.set(first,w);
   668 // 	  right.set(w,first);
   669 // 	  left.set(w,INVALID);
   670 // 	  level_list[newlevel]=w;
   671 // 	}
   672 //       }
   673 
   674 //     } //relabel
   675 
   676 //   };
   677 
   678 
   679 
   680 //   template <typename Graph, typename Num, typename CapMap, typename FlowMap>
   681 //   void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase1(FlowEnum fe)
   682 //   {
   683 
   684 //     int heur0=(int)(H0*n);  //time while running 'bound decrease'
   685 //     int heur1=(int)(H1*n);  //time while running 'highest label'
   686 //     int heur=heur1;         //starting time interval (#of relabels)
   687 //     int numrelabel=0;
   688 
   689 //     bool what_heur=1;
   690 //     //It is 0 in case 'bound decrease' and 1 in case 'highest label'
   691 
   692 //     bool end=false;
   693 //     //Needed for 'bound decrease', true means no active nodes are above bound
   694 //     //b.
   695 
   696 //     int k=n-2;  //bound on the highest level under n containing a node
   697 //     int b=k;    //bound on the highest level under n of an active node
   698 
   699 //     VecStack active(n);
   700 
   701 //     NNMap left(*g, INVALID);
   702 //     NNMap right(*g, INVALID);
   703 //     VecNode level_list(n,INVALID);
   704 //     //List of the nodes in level i<n, set to n.
   705 
   706 //     NodeIt v;
   707 //     for(g->first(v); g->valid(v); g->next(v)) level.set(v,n);
   708 //     //setting each node to level n
   709 
   710 //     if ( fe == NO_FLOW ) {
   711 //       EdgeIt e;
   712 //       for(g->first(e); g->valid(e); g->next(e)) flow->set(e,0);
   713 //     }
   714 
   715 //     switch (fe) { //computing the excess
   716 //     case PRE_FLOW:
   717 //       {
   718 // 	NodeIt v;
   719 // 	for(g->first(v); g->valid(v); g->next(v)) {
   720 // 	  Num exc=0;
   721 
   722 // 	  InEdgeIt e;
   723 // 	  for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e];
   724 // 	  OutEdgeIt f;
   725 // 	  for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f];
   726 
   727 // 	  excess.set(v,exc);
   728 
   729 // 	  //putting the active nodes into the stack
   730 // 	  int lev=level[v];
   731 // 	  if ( exc > 0 && lev < n && v != t ) active[lev].push(v);
   732 // 	}
   733 // 	break;
   734 //       }
   735 //     case GEN_FLOW:
   736 //       {
   737 // 	NodeIt v;
   738 // 	for(g->first(v); g->valid(v); g->next(v)) excess.set(v,0);
   739 
   740 // 	Num exc=0;
   741 // 	InEdgeIt e;
   742 // 	for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e];
   743 // 	OutEdgeIt f;
   744 // 	for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f];
   745 // 	excess.set(t,exc);
   746 // 	break;
   747 //       }
   748 //     case ZERO_FLOW:
   749 //     case NO_FLOW:
   750 //       {
   751 // 	NodeIt v;
   752 //         for(g->first(v); g->valid(v); g->next(v)) excess.set(v,0);
   753 // 	break;
   754 //       }
   755 //     }
   756 
   757 //     preflowPreproc(fe, active, level_list, left, right);
   758 //     //End of preprocessing
   759 
   760 
   761 //     //Push/relabel on the highest level active nodes.
   762 //     while ( true ) {
   763 //       if ( b == 0 ) {
   764 // 	if ( !what_heur && !end && k > 0 ) {
   765 // 	  b=k;
   766 // 	  end=true;
   767 // 	} else break;
   768 //       }
   769 
   770 //       if ( active[b].empty() ) --b;
   771 //       else {
   772 // 	end=false;
   773 // 	Node w=active[b].top();
   774 // 	active[b].pop();
   775 // 	int newlevel=push(w,active);
   776 // 	if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list,
   777 // 				     left, right, b, k, what_heur);
   778 
   779 // 	++numrelabel;
   780 // 	if ( numrelabel >= heur ) {
   781 // 	  numrelabel=0;
   782 // 	  if ( what_heur ) {
   783 // 	    what_heur=0;
   784 // 	    heur=heur0;
   785 // 	    end=false;
   786 // 	  } else {
   787 // 	    what_heur=1;
   788 // 	    heur=heur1;
   789 // 	    b=k;
   790 // 	  }
   791 // 	}
   792 //       }
   793 //     }
   794 
   795 //     status=AFTER_PRE_FLOW_PHASE_1;
   796 //   }
   797 
   798 
   799 
   800 //   template <typename Graph, typename Num, typename CapMap, typename FlowMap>
   801 //   void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase2()
   802 //   {
   803 
   804 //     int k=n-2;  //bound on the highest level under n containing a node
   805 //     int b=k;    //bound on the highest level under n of an active node
   806 
   807 //     VecStack active(n);
   808 //     level.set(s,0);
   809 //     std::queue<Node> bfs_queue;
   810 //     bfs_queue.push(s);
   811 
   812 //     while (!bfs_queue.empty()) {
   813 
   814 //       Node v=bfs_queue.front();
   815 //       bfs_queue.pop();
   816 //       int l=level[v]+1;
   817 
   818 //       InEdgeIt e;
   819 //       for(g->first(e,v); g->valid(e); g->next(e)) {
   820 // 	if ( (*capacity)[e] <= (*flow)[e] ) continue;
   821 // 	Node u=g->tail(e);
   822 // 	if ( level[u] >= n ) {
   823 // 	  bfs_queue.push(u);
   824 // 	  level.set(u, l);
   825 // 	  if ( excess[u] > 0 ) active[l].push(u);
   826 // 	}
   827 //       }
   828 
   829 //       OutEdgeIt f;
   830 //       for(g->first(f,v); g->valid(f); g->next(f)) {
   831 // 	if ( 0 >= (*flow)[f] ) continue;
   832 // 	Node u=g->head(f);
   833 // 	if ( level[u] >= n ) {
   834 // 	  bfs_queue.push(u);
   835 // 	  level.set(u, l);
   836 // 	  if ( excess[u] > 0 ) active[l].push(u);
   837 // 	}
   838 //       }
   839 //     }
   840 //     b=n-2;
   841 
   842 //     while ( true ) {
   843 
   844 //       if ( b == 0 ) break;
   845 
   846 //       if ( active[b].empty() ) --b;
   847 //       else {
   848 // 	Node w=active[b].top();
   849 // 	active[b].pop();
   850 // 	int newlevel=push(w,active);
   851 
   852 // 	//relabel
   853 // 	if ( excess[w] > 0 ) {
   854 // 	  level.set(w,++newlevel);
   855 // 	  active[newlevel].push(w);
   856 // 	  b=newlevel;
   857 // 	}
   858 //       }  // if stack[b] is nonempty
   859 //     } // while(true)
   860 
   861 //     status=AFTER_PRE_FLOW_PHASE_2;
   862 //   }
   863 
   864 
   865   template <typename Graph, typename Num,
   866 	    typename CapMap=typename Graph::template EdgeMap<Num>,
   867             typename FlowMap=typename Graph::template EdgeMap<Num> >
   868   class AugmentingFlow {
   869   protected:
   870     typedef typename Graph::Node Node;
   871     typedef typename Graph::NodeIt NodeIt;
   872     typedef typename Graph::EdgeIt EdgeIt;
   873     typedef typename Graph::OutEdgeIt OutEdgeIt;
   874     typedef typename Graph::InEdgeIt InEdgeIt;
   875 
   876 //    typedef typename std::vector<std::stack<Node> > VecStack;
   877 //    typedef typename Graph::template NodeMap<Node> NNMap;
   878 //    typedef typename std::vector<Node> VecNode;
   879 
   880     const Graph* g;
   881     Node s;
   882     Node t;
   883     const CapMap* capacity;
   884     FlowMap* flow;
   885 //    int n;      //the number of nodes of G
   886     typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;   
   887     //typedef ExpResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
   888     typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
   889     typedef typename ResGW::Edge ResGWEdge;
   890     //typedef typename ResGW::template NodeMap<bool> ReachedMap;
   891     typedef typename Graph::template NodeMap<int> ReachedMap;
   892 
   893 
   894     //level works as a bool map in augmenting path algorithms and is
   895     //used by bfs for storing reached information.  In preflow, it
   896     //shows the levels of nodes.     
   897     ReachedMap level;
   898 
   899     //excess is needed only in preflow
   900 //    typename Graph::template NodeMap<Num> excess;
   901 
   902     //fixme    
   903 //   protected:
   904     //     MaxFlow() { }
   905     //     void set(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
   906     // 	     FlowMap& _flow)
   907     //       {
   908     // 	g=&_G;
   909     // 	s=_s;
   910     // 	t=_t;
   911     // 	capacity=&_capacity;
   912     // 	flow=&_flow;
   913     // 	n=_G.nodeNum;
   914     // 	level.set (_G); //kellene vmi ilyesmi fv
   915     // 	excess(_G,0); //itt is
   916     //       }
   917 
   918     // constants used for heuristics
   919 //    static const int H0=20;
   920 //    static const int H1=1;
   921 
   922   public:
   923 
   924     ///Indicates the property of the starting flow.
   925 
   926     ///Indicates the property of the starting flow. The meanings are as follows:
   927     ///- \c ZERO_FLOW: constant zero flow
   928     ///- \c GEN_FLOW: any flow, i.e. the sum of the in-flows equals to
   929     ///the sum of the out-flows in every node except the \e source and
   930     ///the \e target.
   931     ///- \c PRE_FLOW: any preflow, i.e. the sum of the in-flows is at 
   932     ///least the sum of the out-flows in every node except the \e source.
   933     ///- \c NO_FLOW: indicates an unspecified edge map. \ref flow will be 
   934     ///set to the constant zero flow in the beginning of the algorithm in this case.
   935     enum FlowEnum{
   936       ZERO_FLOW,
   937       GEN_FLOW,
   938       PRE_FLOW,
   939       NO_FLOW
   940     };
   941 
   942     enum StatusEnum {
   943       AFTER_NOTHING,
   944       AFTER_AUGMENTING,
   945       AFTER_FAST_AUGMENTING, 
   946       AFTER_PRE_FLOW_PHASE_1,      
   947       AFTER_PRE_FLOW_PHASE_2
   948     };
   949 
   950     /// Don not needle this flag only if necessary.
   951     StatusEnum status;
   952     int number_of_augmentations;
   953 
   954 
   955     template<typename IntMap>
   956     class TrickyReachedMap {
   957     protected:
   958       IntMap* map;
   959       int* number_of_augmentations;
   960     public:
   961       TrickyReachedMap(IntMap& _map, int& _number_of_augmentations) : 
   962 	map(&_map), number_of_augmentations(&_number_of_augmentations) { }
   963       void set(const Node& n, bool b) {
   964 	if (b)
   965 	  map->set(n, *number_of_augmentations);
   966 	else 
   967 	  map->set(n, *number_of_augmentations-1);
   968       }
   969       bool operator[](const Node& n) const { 
   970 	return (*map)[n]==*number_of_augmentations; 
   971       }
   972     };
   973     
   974     AugmentingFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
   975 		   FlowMap& _flow) :
   976       g(&_G), s(_s), t(_t), capacity(&_capacity),
   977       flow(&_flow), //n(_G.nodeNum()), 
   978       level(_G), //excess(_G,0), 
   979       status(AFTER_NOTHING), number_of_augmentations(0) { }
   980 
   981     /// Starting from a flow, this method searches for an augmenting path
   982     /// according to the Edmonds-Karp algorithm
   983     /// and augments the flow on if any.
   984     /// The return value shows if the augmentation was succesful.
   985     bool augmentOnShortestPath();
   986     bool augmentOnShortestPath2();
   987 
   988     /// Starting from a flow, this method searches for an augmenting blocking
   989     /// flow according to Dinits' algorithm and augments the flow on if any.
   990     /// The blocking flow is computed in a physically constructed
   991     /// residual graph of type \c Mutablegraph.
   992     /// The return value show sif the augmentation was succesful.
   993     template<typename MutableGraph> bool augmentOnBlockingFlow();
   994 
   995     /// The same as \c augmentOnBlockingFlow<MutableGraph> but the
   996     /// residual graph is not constructed physically.
   997     /// The return value shows if the augmentation was succesful.
   998     bool augmentOnBlockingFlow2();
   999 
  1000     template<typename _CutMap>
  1001     void actMinCut(_CutMap& M) const {
  1002       NodeIt v;
  1003       switch (status) {
  1004 	case AFTER_PRE_FLOW_PHASE_1:
  1005 //	std::cout << "AFTER_PRE_FLOW_PHASE_1" << std::endl;
  1006 // 	for(g->first(v); g->valid(v); g->next(v)) {
  1007 // 	  if (level[v] < n) {
  1008 // 	    M.set(v, false);
  1009 // 	  } else {
  1010 // 	    M.set(v, true);
  1011 // 	  }
  1012 // 	}
  1013 	break;
  1014       case AFTER_PRE_FLOW_PHASE_2:
  1015 //	std::cout << "AFTER_PRE_FLOW_PHASE_2" << std::endl;
  1016 	break;
  1017       case AFTER_NOTHING:
  1018 //	std::cout << "AFTER_NOTHING" << std::endl;
  1019 	minMinCut(M);
  1020 	break;
  1021       case AFTER_AUGMENTING:
  1022 //	std::cout << "AFTER_AUGMENTING" << std::endl;
  1023 	for(g->first(v); v!=INVALID; ++v) {
  1024 	  if (level[v]) {
  1025 	    M.set(v, true);
  1026 	  } else {
  1027 	    M.set(v, false);
  1028 	  }
  1029 	}
  1030 	break;
  1031       case AFTER_FAST_AUGMENTING:
  1032 //	std::cout << "AFTER_FAST_AUGMENTING" << std::endl;
  1033 	for(g->first(v); v!=INVALID; ++v) {
  1034 	  if (level[v]==number_of_augmentations) {
  1035 	    M.set(v, true);
  1036 	  } else {
  1037 	    M.set(v, false);
  1038 	  }
  1039 	}
  1040 	break;
  1041       }
  1042     }
  1043 
  1044     template<typename _CutMap>
  1045     void minMinCut(_CutMap& M) const {
  1046       std::queue<Node> queue;
  1047 
  1048       M.set(s,true);
  1049       queue.push(s);
  1050 
  1051       while (!queue.empty()) {
  1052         Node w=queue.front();
  1053 	queue.pop();
  1054 
  1055 	OutEdgeIt e;
  1056 	for(g->first(e,w) ; e!=INVALID; ++e) {
  1057 	  Node v=g->head(e);
  1058 	  if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
  1059 	    queue.push(v);
  1060 	    M.set(v, true);
  1061 	  }
  1062 	}
  1063 
  1064 	InEdgeIt f;
  1065 	for(g->first(f,w) ; f!=INVALID; ++f) {
  1066 	  Node v=g->tail(f);
  1067 	  if (!M[v] && (*flow)[f] > 0 ) {
  1068 	    queue.push(v);
  1069 	    M.set(v, true);
  1070 	  }
  1071 	}
  1072       }
  1073     }
  1074 
  1075     template<typename _CutMap>
  1076     void minMinCut2(_CutMap& M) const {
  1077       ResGW res_graph(*g, *capacity, *flow);
  1078       BfsIterator<ResGW, _CutMap> bfs(res_graph, M);
  1079       bfs.pushAndSetReached(s);
  1080       while (!bfs.finished()) ++bfs;
  1081     }
  1082 
  1083     Num flowValue() const {
  1084       Num a=0;
  1085       for (InEdgeIt e(*g, t); e!=INVALID; ++e) a+=(*flow)[e];
  1086       for (OutEdgeIt e(*g, t); e!=INVALID; ++e) a-=(*flow)[e];
  1087       return a;
  1088       //marci figyu: excess[t] epp ezt adja preflow 1. fazisa utan   
  1089     }
  1090 
  1091     template<typename MapGraphWrapper>
  1092     class DistanceMap {
  1093     protected:
  1094       const MapGraphWrapper* g;
  1095       typename MapGraphWrapper::template NodeMap<int> dist;
  1096     public:
  1097       DistanceMap(MapGraphWrapper& _g) : g(&_g), dist(*g, g->nodeNum()) { }
  1098       void set(const typename MapGraphWrapper::Node& n, int a) {
  1099 	dist.set(n, a);
  1100       }
  1101       int operator[](const typename MapGraphWrapper::Node& n) const { 
  1102 	return dist[n]; 
  1103       }
  1104       //       int get(const typename MapGraphWrapper::Node& n) const {
  1105       // 	return dist[n]; }
  1106       //       bool get(const typename MapGraphWrapper::Edge& e) const {
  1107       // 	return (dist.get(g->tail(e))<dist.get(g->head(e))); }
  1108       bool operator[](const typename MapGraphWrapper::Edge& e) const {
  1109 	return (dist[g->tail(e)]<dist[g->head(e)]);
  1110       }
  1111     };
  1112 
  1113   };
  1114 
  1115 
  1116 
  1117   template <typename Graph, typename Num, typename CapMap, typename FlowMap>
  1118   bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath()
  1119   {
  1120     ResGW res_graph(*g, *capacity, *flow);
  1121     bool _augment=false;
  1122 
  1123     //ReachedMap level(res_graph);
  1124     for (typename Graph::NodeIt n(*g); n!=INVALID; ++n) level.set(n, 0);
  1125     BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
  1126     bfs.pushAndSetReached(s);
  1127 
  1128     typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
  1129     pred.set(s, INVALID);
  1130 
  1131     typename ResGW::template NodeMap<Num> free(res_graph);
  1132 
  1133     //searching for augmenting path
  1134     while ( !bfs.finished() ) {
  1135       ResGWEdge e=bfs;
  1136       if (e!=INVALID && bfs.isBNodeNewlyReached()) {
  1137 	Node v=res_graph.tail(e);
  1138 	Node w=res_graph.head(e);
  1139 	pred.set(w, e);
  1140 	if (pred[v]!=INVALID) {
  1141 	  free.set(w, std::min(free[v], res_graph.resCap(e)));
  1142 	} else {
  1143 	  free.set(w, res_graph.resCap(e));
  1144 	}
  1145 	if (res_graph.head(e)==t) { _augment=true; break; }
  1146       }
  1147 
  1148       ++bfs;
  1149     } //end of searching augmenting path
  1150 
  1151     if (_augment) {
  1152       Node n=t;
  1153       Num augment_value=free[t];
  1154       while (pred[n]!=INVALID) {
  1155 	ResGWEdge e=pred[n];
  1156 	res_graph.augment(e, augment_value);
  1157 	n=res_graph.tail(e);
  1158       }
  1159     }
  1160 
  1161     status=AFTER_AUGMENTING;
  1162     return _augment;
  1163   }
  1164 
  1165   template <typename Graph, typename Num, typename CapMap, typename FlowMap>
  1166   bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath2()
  1167   {
  1168     ResGW res_graph(*g, *capacity, *flow);
  1169     bool _augment=false;
  1170 
  1171     if (status!=AFTER_FAST_AUGMENTING) {
  1172       for (typename Graph::NodeIt n(*g); n!=INVALID; ++n) level.set(n, 0); 
  1173       number_of_augmentations=1;
  1174     } else {
  1175       ++number_of_augmentations;
  1176     }
  1177     TrickyReachedMap<ReachedMap> 
  1178       tricky_reached_map(level, number_of_augmentations);
  1179     //ReachedMap level(res_graph);
  1180 //    FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
  1181     BfsIterator<ResGW, TrickyReachedMap<ReachedMap> > 
  1182       bfs(res_graph, tricky_reached_map);
  1183     bfs.pushAndSetReached(s);
  1184 
  1185     typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
  1186     pred.set(s, INVALID);
  1187 
  1188     typename ResGW::template NodeMap<Num> free(res_graph);
  1189 
  1190     //searching for augmenting path
  1191     while ( !bfs.finished() ) {
  1192       ResGWEdge e=bfs;
  1193       if (e!=INVALID && bfs.isBNodeNewlyReached()) {
  1194 	Node v=res_graph.tail(e);
  1195 	Node w=res_graph.head(e);
  1196 	pred.set(w, e);
  1197 	if (pred[v]!=INVALID) {
  1198 	  free.set(w, std::min(free[v], res_graph.resCap(e)));
  1199 	} else {
  1200 	  free.set(w, res_graph.resCap(e));
  1201 	}
  1202 	if (res_graph.head(e)==t) { _augment=true; break; }
  1203       }
  1204 
  1205       ++bfs;
  1206     } //end of searching augmenting path
  1207 
  1208     if (_augment) {
  1209       Node n=t;
  1210       Num augment_value=free[t];
  1211       while (pred[n]!=INVALID) {
  1212 	ResGWEdge e=pred[n];
  1213 	res_graph.augment(e, augment_value);
  1214 	n=res_graph.tail(e);
  1215       }
  1216     }
  1217 
  1218     status=AFTER_FAST_AUGMENTING;
  1219     return _augment;
  1220   }
  1221 
  1222 
  1223   template <typename Graph, typename Num, typename CapMap, typename FlowMap>
  1224   template<typename MutableGraph>
  1225   bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow()
  1226   {
  1227     typedef MutableGraph MG;
  1228     bool _augment=false;
  1229 
  1230     ResGW res_graph(*g, *capacity, *flow);
  1231 
  1232     //bfs for distances on the residual graph
  1233     //ReachedMap level(res_graph);
  1234     for (typename Graph::NodeIt n(*g); n!=INVALID; ++n) level.set(n, 0);
  1235     BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
  1236     bfs.pushAndSetReached(s);
  1237     typename ResGW::template NodeMap<int>
  1238       dist(res_graph); //filled up with 0's
  1239 
  1240     //F will contain the physical copy of the residual graph
  1241     //with the set of edges which are on shortest paths
  1242     MG F;
  1243     typename ResGW::template NodeMap<typename MG::Node>
  1244       res_graph_to_F(res_graph);
  1245     {
  1246       typename ResGW::NodeIt n;
  1247       for(res_graph.first(n); n!=INVALID; ++n) {
  1248 	res_graph_to_F.set(n, F.addNode());
  1249       }
  1250     }
  1251 
  1252     typename MG::Node sF=res_graph_to_F[s];
  1253     typename MG::Node tF=res_graph_to_F[t];
  1254     typename MG::template EdgeMap<ResGWEdge> original_edge(F);
  1255     typename MG::template EdgeMap<Num> residual_capacity(F);
  1256 
  1257     while ( !bfs.finished() ) {
  1258       ResGWEdge e=bfs;
  1259       if (e!=INVALID) {
  1260 	if (bfs.isBNodeNewlyReached()) {
  1261 	  dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
  1262 	  typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)],
  1263 					res_graph_to_F[res_graph.head(e)]);
  1264 	  original_edge.update();
  1265 	  original_edge.set(f, e);
  1266 	  residual_capacity.update();
  1267 	  residual_capacity.set(f, res_graph.resCap(e));
  1268 	} else {
  1269 	  if (dist[res_graph.head(e)]==(dist[res_graph.tail(e)]+1)) {
  1270 	    typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)],
  1271 					  res_graph_to_F[res_graph.head(e)]);
  1272 	    original_edge.update();
  1273 	    original_edge.set(f, e);
  1274 	    residual_capacity.update();
  1275 	    residual_capacity.set(f, res_graph.resCap(e));
  1276 	  }
  1277 	}
  1278       }
  1279       ++bfs;
  1280     } //computing distances from s in the residual graph
  1281 
  1282     bool __augment=true;
  1283 
  1284     while (__augment) {
  1285       __augment=false;
  1286       //computing blocking flow with dfs
  1287       DfsIterator< MG, typename MG::template NodeMap<bool> > dfs(F);
  1288       typename MG::template NodeMap<typename MG::Edge> pred(F);
  1289       pred.set(sF, INVALID);
  1290       //invalid iterators for sources
  1291 
  1292       typename MG::template NodeMap<Num> free(F);
  1293 
  1294       dfs.pushAndSetReached(sF);
  1295       while (!dfs.finished()) {
  1296 	++dfs;
  1297 	if (F.valid(/*typename MG::OutEdgeIt*/(dfs))) {
  1298 	  if (dfs.isBNodeNewlyReached()) {
  1299 	    typename MG::Node v=F.tail(dfs);
  1300 	    typename MG::Node w=F.head(dfs);
  1301 	    pred.set(w, dfs);
  1302 	    if (pred[v]!=INVALID) {
  1303 	      free.set(w, std::min(free[v], residual_capacity[dfs]));
  1304 	    } else {
  1305 	      free.set(w, residual_capacity[dfs]);
  1306 	    }
  1307 	    if (w==tF) {
  1308 	      __augment=true;
  1309 	      _augment=true;
  1310 	      break;
  1311 	    }
  1312 
  1313 	  } else {
  1314 	    F.erase(/*typename MG::OutEdgeIt*/(dfs));
  1315 	  }
  1316 	}
  1317       }
  1318 
  1319       if (__augment) {
  1320 	typename MG::Node n=tF;
  1321 	Num augment_value=free[tF];
  1322 	while (pred[n]!=INVALID) {
  1323 	  typename MG::Edge e=pred[n];
  1324 	  res_graph.augment(original_edge[e], augment_value);
  1325 	  n=F.tail(e);
  1326 	  if (residual_capacity[e]==augment_value)
  1327 	    F.erase(e);
  1328 	  else
  1329 	    residual_capacity.set(e, residual_capacity[e]-augment_value);
  1330 	}
  1331       }
  1332 
  1333     }
  1334 
  1335     status=AFTER_AUGMENTING;
  1336     return _augment;
  1337   }
  1338 
  1339 
  1340   template <typename Graph, typename Num, typename CapMap, typename FlowMap>
  1341   bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow2()
  1342   {
  1343     bool _augment=false;
  1344 
  1345     ResGW res_graph(*g, *capacity, *flow);
  1346 
  1347     //ReachedMap level(res_graph);
  1348     for (typename Graph::NodeIt n(*g); n!=INVALID; ++n) level.set(n, 0);
  1349     BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
  1350 
  1351     bfs.pushAndSetReached(s);
  1352     DistanceMap<ResGW> dist(res_graph);
  1353     while ( !bfs.finished() ) {
  1354       ResGWEdge e=bfs;
  1355       if (e!=INVALID && bfs.isBNodeNewlyReached()) {
  1356 	dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
  1357       }
  1358       ++bfs;
  1359     } //computing distances from s in the residual graph
  1360 
  1361     //Subgraph containing the edges on some shortest paths
  1362     ConstMap<typename ResGW::Node, bool> true_map(true);
  1363     typedef SubGraphWrapper<ResGW, ConstMap<typename ResGW::Node, bool>,
  1364       DistanceMap<ResGW> > FilterResGW;
  1365     FilterResGW filter_res_graph(res_graph, true_map, dist);
  1366 
  1367     //Subgraph, which is able to delete edges which are already
  1368     //met by the dfs
  1369     typename FilterResGW::template NodeMap<typename FilterResGW::Edge>
  1370       first_out_edges(filter_res_graph);
  1371     typename FilterResGW::NodeIt v;
  1372     for(filter_res_graph.first(v); v!=INVALID; ++v)
  1373       {
  1374   	typename FilterResGW::OutEdgeIt e;
  1375   	filter_res_graph.first(e, v);
  1376   	first_out_edges.set(v, e);
  1377       }
  1378     typedef ErasingFirstGraphWrapper<FilterResGW, typename FilterResGW::
  1379       template NodeMap<typename FilterResGW::Edge> > ErasingResGW;
  1380     ErasingResGW erasing_res_graph(filter_res_graph, first_out_edges);
  1381 
  1382     bool __augment=true;
  1383 
  1384     while (__augment) {
  1385 
  1386       __augment=false;
  1387       //computing blocking flow with dfs
  1388       DfsIterator< ErasingResGW,
  1389 	typename ErasingResGW::template NodeMap<bool> >
  1390 	dfs(erasing_res_graph);
  1391       typename ErasingResGW::
  1392 	template NodeMap<typename ErasingResGW::Edge> pred(erasing_res_graph);
  1393       pred.set(s, INVALID);
  1394       //invalid iterators for sources
  1395 
  1396       typename ErasingResGW::template NodeMap<Num>
  1397 	free1(erasing_res_graph);
  1398 
  1399       dfs.pushAndSetReached
  1400 	/// \bug hugo 0.2
  1401 	(typename ErasingResGW::Node
  1402 	 (typename FilterResGW::Node
  1403 	  (typename ResGW::Node(s)
  1404 	   )
  1405 	  )
  1406 	 );
  1407 	
  1408       while (!dfs.finished()) {
  1409 	++dfs;
  1410 	if (typename ErasingResGW::Edge(dfs)!=INVALID)
  1411  	  {
  1412   	    if (dfs.isBNodeNewlyReached()) {
  1413 
  1414  	      typename ErasingResGW::Node v=erasing_res_graph.tail(dfs);
  1415  	      typename ErasingResGW::Node w=erasing_res_graph.head(dfs);
  1416 
  1417  	      pred.set(w, typename ErasingResGW::Edge(dfs));
  1418  	      if (pred[v]!=INVALID) {
  1419  		free1.set
  1420 		  (w, std::min(free1[v], res_graph.resCap
  1421 			       (typename ErasingResGW::Edge(dfs))));
  1422  	      } else {
  1423  		free1.set
  1424 		  (w, res_graph.resCap
  1425 		   (typename ErasingResGW::Edge(dfs)));
  1426  	      }
  1427 
  1428  	      if (w==t) {
  1429  		__augment=true;
  1430  		_augment=true;
  1431  		break;
  1432  	      }
  1433  	    } else {
  1434  	      erasing_res_graph.erase(dfs);
  1435 	    }
  1436 	  }
  1437       }
  1438 
  1439       if (__augment) {
  1440 	typename ErasingResGW::Node
  1441 	  n=typename FilterResGW::Node(typename ResGW::Node(t));
  1442 	// 	  typename ResGW::NodeMap<Num> a(res_graph);
  1443 	// 	  typename ResGW::Node b;
  1444 	// 	  Num j=a[b];
  1445 	// 	  typename FilterResGW::NodeMap<Num> a1(filter_res_graph);
  1446 	// 	  typename FilterResGW::Node b1;
  1447 	// 	  Num j1=a1[b1];
  1448 	// 	  typename ErasingResGW::NodeMap<Num> a2(erasing_res_graph);
  1449 	// 	  typename ErasingResGW::Node b2;
  1450 	// 	  Num j2=a2[b2];
  1451 	Num augment_value=free1[n];
  1452 	while (pred[n]!=INVALID) {
  1453 	  typename ErasingResGW::Edge e=pred[n];
  1454 	  res_graph.augment(e, augment_value);
  1455 	  n=erasing_res_graph.tail(e);
  1456 	  if (res_graph.resCap(e)==0)
  1457 	    erasing_res_graph.erase(e);
  1458 	}
  1459       }
  1460 
  1461     } //while (__augment)
  1462 
  1463     status=AFTER_AUGMENTING;
  1464     return _augment;
  1465   }
  1466 
  1467 
  1468 } //namespace hugo
  1469 
  1470 #endif //HUGO_AUGMENTING_FLOW_H
  1471 
  1472 
  1473 
  1474