1.1 --- a/src/work/jacint/max_flow.h Sun Apr 17 18:57:22 2005 +0000
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,1269 +0,0 @@
1.4 -// -*- C++ -*-
1.5 -#ifndef LEMON_MAX_FLOW_H
1.6 -#define LEMON_MAX_FLOW_H
1.7 -
1.8 -#include <vector>
1.9 -#include <queue>
1.10 -#include <stack>
1.11 -
1.12 -#include <lemon/graph_wrapper.h>
1.13 -#include <bfs_dfs.h>
1.14 -#include <lemon/invalid.h>
1.15 -#include <lemon/maps.h>
1.16 -#include <lemon/for_each_macros.h>
1.17 -
1.18 -/// \file
1.19 -/// \brief Maximum flow algorithms.
1.20 -/// \ingroup galgs
1.21 -
1.22 -namespace lemon {
1.23 -
1.24 - /// \addtogroup galgs
1.25 - /// @{
1.26 - ///Maximum flow algorithms class.
1.27 -
1.28 - ///This class provides various algorithms for finding a flow of
1.29 - ///maximum value in a directed graph. The \e source node, the \e
1.30 - ///target node, the \e capacity of the edges and the \e starting \e
1.31 - ///flow value of the edges should be passed to the algorithm through the
1.32 - ///constructor. It is possible to change these quantities using the
1.33 - ///functions \ref resetSource, \ref resetTarget, \ref resetCap and
1.34 - ///\ref resetFlow. Before any subsequent runs of any algorithm of
1.35 - ///the class \ref resetFlow should be called.
1.36 -
1.37 - ///After running an algorithm of the class, the actual flow value
1.38 - ///can be obtained by calling \ref flowValue(). The minimum
1.39 - ///value cut can be written into a \c node map of \c bools by
1.40 - ///calling \ref minCut. (\ref minMinCut and \ref maxMinCut writes
1.41 - ///the inclusionwise minimum and maximum of the minimum value
1.42 - ///cuts, resp.)
1.43 - ///\param Graph The directed graph type the algorithm runs on.
1.44 - ///\param Num The number type of the capacities and the flow values.
1.45 - ///\param CapMap The capacity map type.
1.46 - ///\param FlowMap The flow map type.
1.47 - ///\author Marton Makai, Jacint Szabo
1.48 - template <typename Graph, typename Num,
1.49 - typename CapMap=typename Graph::template EdgeMap<Num>,
1.50 - typename FlowMap=typename Graph::template EdgeMap<Num> >
1.51 - class MaxFlow {
1.52 - protected:
1.53 - typedef typename Graph::Node Node;
1.54 - typedef typename Graph::NodeIt NodeIt;
1.55 - typedef typename Graph::EdgeIt EdgeIt;
1.56 - typedef typename Graph::OutEdgeIt OutEdgeIt;
1.57 - typedef typename Graph::InEdgeIt InEdgeIt;
1.58 -
1.59 - typedef typename std::vector<std::stack<Node> > VecStack;
1.60 - typedef typename Graph::template NodeMap<Node> NNMap;
1.61 - typedef typename std::vector<Node> VecNode;
1.62 -
1.63 - const Graph* g;
1.64 - Node s;
1.65 - Node t;
1.66 - const CapMap* capacity;
1.67 - FlowMap* flow;
1.68 - int n; //the number of nodes of G
1.69 - typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
1.70 - //typedef ExpResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
1.71 - typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
1.72 - typedef typename ResGW::Edge ResGWEdge;
1.73 - //typedef typename ResGW::template NodeMap<bool> ReachedMap;
1.74 - typedef typename Graph::template NodeMap<int> ReachedMap;
1.75 -
1.76 -
1.77 - //level works as a bool map in augmenting path algorithms and is
1.78 - //used by bfs for storing reached information. In preflow, it
1.79 - //shows the levels of nodes.
1.80 - ReachedMap level;
1.81 -
1.82 - //excess is needed only in preflow
1.83 - typename Graph::template NodeMap<Num> excess;
1.84 -
1.85 - //fixme
1.86 -// protected:
1.87 - // MaxFlow() { }
1.88 - // void set(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
1.89 - // FlowMap& _flow)
1.90 - // {
1.91 - // g=&_G;
1.92 - // s=_s;
1.93 - // t=_t;
1.94 - // capacity=&_capacity;
1.95 - // flow=&_flow;
1.96 - // n=_G.nodeNum;
1.97 - // level.set (_G); //kellene vmi ilyesmi fv
1.98 - // excess(_G,0); //itt is
1.99 - // }
1.100 -
1.101 - // constants used for heuristics
1.102 - static const int H0=20;
1.103 - static const int H1=1;
1.104 -
1.105 - public:
1.106 -
1.107 - ///Indicates the property of the starting flow.
1.108 -
1.109 - ///Indicates the property of the starting flow. The meanings are as follows:
1.110 - ///- \c ZERO_FLOW: constant zero flow
1.111 - ///- \c GEN_FLOW: any flow, i.e. the sum of the in-flows equals to
1.112 - ///the sum of the out-flows in every node except the \e source and
1.113 - ///the \e target.
1.114 - ///- \c PRE_FLOW: any preflow, i.e. the sum of the in-flows is at
1.115 - ///least the sum of the out-flows in every node except the \e source.
1.116 - ///- \c NO_FLOW: indicates an unspecified edge map. \ref flow will be
1.117 - ///set to the constant zero flow in the beginning of the algorithm in this case.
1.118 - enum FlowEnum{
1.119 - ZERO_FLOW,
1.120 - GEN_FLOW,
1.121 - PRE_FLOW,
1.122 - NO_FLOW
1.123 - };
1.124 -
1.125 - enum StatusEnum {
1.126 - AFTER_NOTHING,
1.127 - AFTER_AUGMENTING,
1.128 - AFTER_FAST_AUGMENTING,
1.129 - AFTER_PRE_FLOW_PHASE_1,
1.130 - AFTER_PRE_FLOW_PHASE_2
1.131 - };
1.132 -
1.133 - /// Don not needle this flag only if necessary.
1.134 - StatusEnum status;
1.135 - int number_of_augmentations;
1.136 -
1.137 -
1.138 - template<typename IntMap>
1.139 - class TrickyReachedMap {
1.140 - protected:
1.141 - IntMap* map;
1.142 - int* number_of_augmentations;
1.143 - public:
1.144 - TrickyReachedMap(IntMap& _map, int& _number_of_augmentations) :
1.145 - map(&_map), number_of_augmentations(&_number_of_augmentations) { }
1.146 - void set(const Node& n, bool b) {
1.147 - if (b)
1.148 - map->set(n, *number_of_augmentations);
1.149 - else
1.150 - map->set(n, *number_of_augmentations-1);
1.151 - }
1.152 - bool operator[](const Node& n) const {
1.153 - return (*map)[n]==*number_of_augmentations;
1.154 - }
1.155 - };
1.156 -
1.157 - ///Constructor
1.158 -
1.159 - ///\todo Document, please.
1.160 - ///
1.161 - MaxFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
1.162 - FlowMap& _flow) :
1.163 - g(&_G), s(_s), t(_t), capacity(&_capacity),
1.164 - flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0),
1.165 - status(AFTER_NOTHING), number_of_augmentations(0) { }
1.166 -
1.167 - ///Runs a maximum flow algorithm.
1.168 -
1.169 - ///Runs a preflow algorithm, which is the fastest maximum flow
1.170 - ///algorithm up-to-date. The default for \c fe is ZERO_FLOW.
1.171 - ///\pre The starting flow must be
1.172 - /// - a constant zero flow if \c fe is \c ZERO_FLOW,
1.173 - /// - an arbitary flow if \c fe is \c GEN_FLOW,
1.174 - /// - an arbitary preflow if \c fe is \c PRE_FLOW,
1.175 - /// - any map if \c fe is NO_FLOW.
1.176 - void run(FlowEnum fe=ZERO_FLOW) {
1.177 - preflow(fe);
1.178 - }
1.179 -
1.180 -
1.181 - ///Runs a preflow algorithm.
1.182 -
1.183 - ///Runs a preflow algorithm. The preflow algorithms provide the
1.184 - ///fastest way to compute a maximum flow in a directed graph.
1.185 - ///\pre The starting flow must be
1.186 - /// - a constant zero flow if \c fe is \c ZERO_FLOW,
1.187 - /// - an arbitary flow if \c fe is \c GEN_FLOW,
1.188 - /// - an arbitary preflow if \c fe is \c PRE_FLOW,
1.189 - /// - any map if \c fe is NO_FLOW.
1.190 - ///
1.191 - ///\todo NO_FLOW should be the default flow.
1.192 - void preflow(FlowEnum fe) {
1.193 - preflowPhase1(fe);
1.194 - preflowPhase2();
1.195 - }
1.196 - // Heuristics:
1.197 - // 2 phase
1.198 - // gap
1.199 - // list 'level_list' on the nodes on level i implemented by hand
1.200 - // stack 'active' on the active nodes on level i
1.201 - // runs heuristic 'highest label' for H1*n relabels
1.202 - // runs heuristic 'bound decrease' for H0*n relabels, starts with 'highest label'
1.203 - // Parameters H0 and H1 are initialized to 20 and 1.
1.204 -
1.205 - ///Runs the first phase of the preflow algorithm.
1.206 -
1.207 - ///The preflow algorithm consists of two phases, this method runs the
1.208 - ///first phase. After the first phase the maximum flow value and a
1.209 - ///minimum value cut can already be computed, though a maximum flow
1.210 - ///is net yet obtained. So after calling this method \ref flowValue
1.211 - ///and \ref actMinCut gives proper results.
1.212 - ///\warning: \ref minCut, \ref minMinCut and \ref maxMinCut do not
1.213 - ///give minimum value cuts unless calling \ref preflowPhase2.
1.214 - ///\pre The starting flow must be
1.215 - /// - a constant zero flow if \c fe is \c ZERO_FLOW,
1.216 - /// - an arbitary flow if \c fe is \c GEN_FLOW,
1.217 - /// - an arbitary preflow if \c fe is \c PRE_FLOW,
1.218 - /// - any map if \c fe is NO_FLOW.
1.219 - void preflowPhase1(FlowEnum fe);
1.220 -
1.221 - ///Runs the second phase of the preflow algorithm.
1.222 -
1.223 - ///The preflow algorithm consists of two phases, this method runs
1.224 - ///the second phase. After calling \ref preflowPhase1 and then
1.225 - ///\ref preflowPhase2 the methods \ref flowValue, \ref minCut,
1.226 - ///\ref minMinCut and \ref maxMinCut give proper results.
1.227 - ///\pre \ref preflowPhase1 must be called before.
1.228 - void preflowPhase2();
1.229 -
1.230 - /// Starting from a flow, this method searches for an augmenting path
1.231 - /// according to the Edmonds-Karp algorithm
1.232 - /// and augments the flow on if any.
1.233 - /// The return value shows if the augmentation was succesful.
1.234 - bool augmentOnShortestPath();
1.235 - bool augmentOnShortestPath2();
1.236 -
1.237 - /// Starting from a flow, this method searches for an augmenting blocking
1.238 - /// flow according to Dinits' algorithm and augments the flow on if any.
1.239 - /// The blocking flow is computed in a physically constructed
1.240 - /// residual graph of type \c Mutablegraph.
1.241 - /// The return value show sif the augmentation was succesful.
1.242 - template<typename MutableGraph> bool augmentOnBlockingFlow();
1.243 -
1.244 - /// The same as \c augmentOnBlockingFlow<MutableGraph> but the
1.245 - /// residual graph is not constructed physically.
1.246 - /// The return value shows if the augmentation was succesful.
1.247 - bool augmentOnBlockingFlow2();
1.248 -
1.249 - /// Returns the maximum value of a flow.
1.250 -
1.251 - /// Returns the maximum value of a flow, by counting the
1.252 - /// over-flow of the target node \ref t.
1.253 - /// It can be called already after running \ref preflowPhase1.
1.254 - Num flowValue() const {
1.255 - Num a=0;
1.256 - FOR_EACH_INC_LOC(InEdgeIt, e, *g, t) a+=(*flow)[e];
1.257 - FOR_EACH_INC_LOC(OutEdgeIt, e, *g, t) a-=(*flow)[e];
1.258 - return a;
1.259 - //marci figyu: excess[t] epp ezt adja preflow 1. fazisa utan
1.260 - }
1.261 -
1.262 - ///Returns a minimum value cut after calling \ref preflowPhase1.
1.263 -
1.264 - ///After the first phase of the preflow algorithm the maximum flow
1.265 - ///value and a minimum value cut can already be computed. This
1.266 - ///method can be called after running \ref preflowPhase1 for
1.267 - ///obtaining a minimum value cut.
1.268 - /// \warning Gives proper result only right after calling \ref
1.269 - /// preflowPhase1.
1.270 - /// \todo We have to make some status variable which shows the
1.271 - /// actual state
1.272 - /// of the class. This enables us to determine which methods are valid
1.273 - /// for MinCut computation
1.274 - template<typename _CutMap>
1.275 - void actMinCut(_CutMap& M) const {
1.276 - NodeIt v;
1.277 - switch (status) {
1.278 - case AFTER_PRE_FLOW_PHASE_1:
1.279 - for(g->first(v); g->valid(v); g->next(v)) {
1.280 - if (level[v] < n) {
1.281 - M.set(v, false);
1.282 - } else {
1.283 - M.set(v, true);
1.284 - }
1.285 - }
1.286 - break;
1.287 - case AFTER_PRE_FLOW_PHASE_2:
1.288 - case AFTER_NOTHING:
1.289 - minMinCut(M);
1.290 - break;
1.291 - case AFTER_AUGMENTING:
1.292 - for(g->first(v); g->valid(v); g->next(v)) {
1.293 - if (level[v]) {
1.294 - M.set(v, true);
1.295 - } else {
1.296 - M.set(v, false);
1.297 - }
1.298 - }
1.299 - break;
1.300 - case AFTER_FAST_AUGMENTING:
1.301 - for(g->first(v); g->valid(v); g->next(v)) {
1.302 - if (level[v]==number_of_augmentations) {
1.303 - M.set(v, true);
1.304 - } else {
1.305 - M.set(v, false);
1.306 - }
1.307 - }
1.308 - break;
1.309 - }
1.310 - }
1.311 -
1.312 - ///Returns the inclusionwise minimum of the minimum value cuts.
1.313 -
1.314 - ///Sets \c M to the characteristic vector of the minimum value cut
1.315 - ///which is inclusionwise minimum. It is computed by processing
1.316 - ///a bfs from the source node \c s in the residual graph.
1.317 - ///\pre M should be a node map of bools initialized to false.
1.318 - ///\pre \c flow must be a maximum flow.
1.319 - template<typename _CutMap>
1.320 - void minMinCut(_CutMap& M) const {
1.321 - std::queue<Node> queue;
1.322 -
1.323 - M.set(s,true);
1.324 - queue.push(s);
1.325 -
1.326 - while (!queue.empty()) {
1.327 - Node w=queue.front();
1.328 - queue.pop();
1.329 -
1.330 - OutEdgeIt e;
1.331 - for(g->first(e,w) ; g->valid(e); g->next(e)) {
1.332 - Node v=g->target(e);
1.333 - if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
1.334 - queue.push(v);
1.335 - M.set(v, true);
1.336 - }
1.337 - }
1.338 -
1.339 - InEdgeIt f;
1.340 - for(g->first(f,w) ; g->valid(f); g->next(f)) {
1.341 - Node v=g->source(f);
1.342 - if (!M[v] && (*flow)[f] > 0 ) {
1.343 - queue.push(v);
1.344 - M.set(v, true);
1.345 - }
1.346 - }
1.347 - }
1.348 - }
1.349 -
1.350 - ///Returns the inclusionwise maximum of the minimum value cuts.
1.351 -
1.352 - ///Sets \c M to the characteristic vector of the minimum value cut
1.353 - ///which is inclusionwise maximum. It is computed by processing a
1.354 - ///backward bfs from the target node \c t in the residual graph.
1.355 - ///\pre M should be a node map of bools initialized to false.
1.356 - ///\pre \c flow must be a maximum flow.
1.357 - template<typename _CutMap>
1.358 - void maxMinCut(_CutMap& M) const {
1.359 -
1.360 - NodeIt v;
1.361 - for(g->first(v) ; g->valid(v); g->next(v)) {
1.362 - M.set(v, true);
1.363 - }
1.364 -
1.365 - std::queue<Node> queue;
1.366 -
1.367 - M.set(t,false);
1.368 - queue.push(t);
1.369 -
1.370 - while (!queue.empty()) {
1.371 - Node w=queue.front();
1.372 - queue.pop();
1.373 -
1.374 - InEdgeIt e;
1.375 - for(g->first(e,w) ; g->valid(e); g->next(e)) {
1.376 - Node v=g->source(e);
1.377 - if (M[v] && (*flow)[e] < (*capacity)[e] ) {
1.378 - queue.push(v);
1.379 - M.set(v, false);
1.380 - }
1.381 - }
1.382 -
1.383 - OutEdgeIt f;
1.384 - for(g->first(f,w) ; g->valid(f); g->next(f)) {
1.385 - Node v=g->target(f);
1.386 - if (M[v] && (*flow)[f] > 0 ) {
1.387 - queue.push(v);
1.388 - M.set(v, false);
1.389 - }
1.390 - }
1.391 - }
1.392 - }
1.393 -
1.394 - ///Returns a minimum value cut.
1.395 -
1.396 - ///Sets \c M to the characteristic vector of a minimum value cut.
1.397 - ///\pre M should be a node map of bools initialized to false.
1.398 - ///\pre \c flow must be a maximum flow.
1.399 - template<typename CutMap>
1.400 - void minCut(CutMap& M) const { minMinCut(M); }
1.401 -
1.402 - ///Resets the source node to \c _s.
1.403 -
1.404 - ///Resets the source node to \c _s.
1.405 - ///
1.406 - void resetSource(Node _s) { s=_s; status=AFTER_NOTHING; }
1.407 -
1.408 - ///Resets the target node to \c _t.
1.409 -
1.410 - ///Resets the target node to \c _t.
1.411 - ///
1.412 - void resetTarget(Node _t) { t=_t; status=AFTER_NOTHING; }
1.413 -
1.414 - /// Resets the edge map of the capacities to _cap.
1.415 -
1.416 - /// Resets the edge map of the capacities to _cap.
1.417 - ///
1.418 - void resetCap(const CapMap& _cap) { capacity=&_cap; status=AFTER_NOTHING; }
1.419 -
1.420 - /// Resets the edge map of the flows to _flow.
1.421 -
1.422 - /// Resets the edge map of the flows to _flow.
1.423 - ///
1.424 - void resetFlow(FlowMap& _flow) { flow=&_flow; status=AFTER_NOTHING; }
1.425 -
1.426 -
1.427 - private:
1.428 -
1.429 - int push(Node w, VecStack& active) {
1.430 -
1.431 - int lev=level[w];
1.432 - Num exc=excess[w];
1.433 - int newlevel=n; //bound on the next level of w
1.434 -
1.435 - OutEdgeIt e;
1.436 - for(g->first(e,w); g->valid(e); g->next(e)) {
1.437 -
1.438 - if ( (*flow)[e] >= (*capacity)[e] ) continue;
1.439 - Node v=g->target(e);
1.440 -
1.441 - if( lev > level[v] ) { //Push is allowed now
1.442 -
1.443 - if ( excess[v]<=0 && v!=t && v!=s ) {
1.444 - int lev_v=level[v];
1.445 - active[lev_v].push(v);
1.446 - }
1.447 -
1.448 - Num cap=(*capacity)[e];
1.449 - Num flo=(*flow)[e];
1.450 - Num remcap=cap-flo;
1.451 -
1.452 - if ( remcap >= exc ) { //A nonsaturating push.
1.453 -
1.454 - flow->set(e, flo+exc);
1.455 - excess.set(v, excess[v]+exc);
1.456 - exc=0;
1.457 - break;
1.458 -
1.459 - } else { //A saturating push.
1.460 - flow->set(e, cap);
1.461 - excess.set(v, excess[v]+remcap);
1.462 - exc-=remcap;
1.463 - }
1.464 - } else if ( newlevel > level[v] ) newlevel = level[v];
1.465 - } //for out edges wv
1.466 -
1.467 - if ( exc > 0 ) {
1.468 - InEdgeIt e;
1.469 - for(g->first(e,w); g->valid(e); g->next(e)) {
1.470 -
1.471 - if( (*flow)[e] <= 0 ) continue;
1.472 - Node v=g->source(e);
1.473 -
1.474 - if( lev > level[v] ) { //Push is allowed now
1.475 -
1.476 - if ( excess[v]<=0 && v!=t && v!=s ) {
1.477 - int lev_v=level[v];
1.478 - active[lev_v].push(v);
1.479 - }
1.480 -
1.481 - Num flo=(*flow)[e];
1.482 -
1.483 - if ( flo >= exc ) { //A nonsaturating push.
1.484 -
1.485 - flow->set(e, flo-exc);
1.486 - excess.set(v, excess[v]+exc);
1.487 - exc=0;
1.488 - break;
1.489 - } else { //A saturating push.
1.490 -
1.491 - excess.set(v, excess[v]+flo);
1.492 - exc-=flo;
1.493 - flow->set(e,0);
1.494 - }
1.495 - } else if ( newlevel > level[v] ) newlevel = level[v];
1.496 - } //for in edges vw
1.497 -
1.498 - } // if w still has excess after the out edge for cycle
1.499 -
1.500 - excess.set(w, exc);
1.501 -
1.502 - return newlevel;
1.503 - }
1.504 -
1.505 -
1.506 - void preflowPreproc(FlowEnum fe, VecStack& active,
1.507 - VecNode& level_list, NNMap& left, NNMap& right)
1.508 - {
1.509 - std::queue<Node> bfs_queue;
1.510 -
1.511 - switch (fe) {
1.512 - case NO_FLOW: //flow is already set to const zero in this case
1.513 - case ZERO_FLOW:
1.514 - {
1.515 - //Reverse_bfs from t, to find the starting level.
1.516 - level.set(t,0);
1.517 - bfs_queue.push(t);
1.518 -
1.519 - while (!bfs_queue.empty()) {
1.520 -
1.521 - Node v=bfs_queue.front();
1.522 - bfs_queue.pop();
1.523 - int l=level[v]+1;
1.524 -
1.525 - InEdgeIt e;
1.526 - for(g->first(e,v); g->valid(e); g->next(e)) {
1.527 - Node w=g->source(e);
1.528 - if ( level[w] == n && w != s ) {
1.529 - bfs_queue.push(w);
1.530 - Node first=level_list[l];
1.531 - if ( g->valid(first) ) left.set(first,w);
1.532 - right.set(w,first);
1.533 - level_list[l]=w;
1.534 - level.set(w, l);
1.535 - }
1.536 - }
1.537 - }
1.538 -
1.539 - //the starting flow
1.540 - OutEdgeIt e;
1.541 - for(g->first(e,s); g->valid(e); g->next(e))
1.542 - {
1.543 - Num c=(*capacity)[e];
1.544 - if ( c <= 0 ) continue;
1.545 - Node w=g->target(e);
1.546 - if ( level[w] < n ) {
1.547 - if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
1.548 - flow->set(e, c);
1.549 - excess.set(w, excess[w]+c);
1.550 - }
1.551 - }
1.552 - break;
1.553 - }
1.554 -
1.555 - case GEN_FLOW:
1.556 - case PRE_FLOW:
1.557 - {
1.558 - //Reverse_bfs from t in the residual graph,
1.559 - //to find the starting level.
1.560 - level.set(t,0);
1.561 - bfs_queue.push(t);
1.562 -
1.563 - while (!bfs_queue.empty()) {
1.564 -
1.565 - Node v=bfs_queue.front();
1.566 - bfs_queue.pop();
1.567 - int l=level[v]+1;
1.568 -
1.569 - InEdgeIt e;
1.570 - for(g->first(e,v); g->valid(e); g->next(e)) {
1.571 - if ( (*capacity)[e] <= (*flow)[e] ) continue;
1.572 - Node w=g->source(e);
1.573 - if ( level[w] == n && w != s ) {
1.574 - bfs_queue.push(w);
1.575 - Node first=level_list[l];
1.576 - if ( g->valid(first) ) left.set(first,w);
1.577 - right.set(w,first);
1.578 - level_list[l]=w;
1.579 - level.set(w, l);
1.580 - }
1.581 - }
1.582 -
1.583 - OutEdgeIt f;
1.584 - for(g->first(f,v); g->valid(f); g->next(f)) {
1.585 - if ( 0 >= (*flow)[f] ) continue;
1.586 - Node w=g->target(f);
1.587 - if ( level[w] == n && w != s ) {
1.588 - bfs_queue.push(w);
1.589 - Node first=level_list[l];
1.590 - if ( g->valid(first) ) left.set(first,w);
1.591 - right.set(w,first);
1.592 - level_list[l]=w;
1.593 - level.set(w, l);
1.594 - }
1.595 - }
1.596 - }
1.597 -
1.598 -
1.599 - //the starting flow
1.600 - OutEdgeIt e;
1.601 - for(g->first(e,s); g->valid(e); g->next(e))
1.602 - {
1.603 - Num rem=(*capacity)[e]-(*flow)[e];
1.604 - if ( rem <= 0 ) continue;
1.605 - Node w=g->target(e);
1.606 - if ( level[w] < n ) {
1.607 - if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
1.608 - flow->set(e, (*capacity)[e]);
1.609 - excess.set(w, excess[w]+rem);
1.610 - }
1.611 - }
1.612 -
1.613 - InEdgeIt f;
1.614 - for(g->first(f,s); g->valid(f); g->next(f))
1.615 - {
1.616 - if ( (*flow)[f] <= 0 ) continue;
1.617 - Node w=g->source(f);
1.618 - if ( level[w] < n ) {
1.619 - if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
1.620 - excess.set(w, excess[w]+(*flow)[f]);
1.621 - flow->set(f, 0);
1.622 - }
1.623 - }
1.624 - break;
1.625 - } //case PRE_FLOW
1.626 - }
1.627 - } //preflowPreproc
1.628 -
1.629 -
1.630 -
1.631 - void relabel(Node w, int newlevel, VecStack& active,
1.632 - VecNode& level_list, NNMap& left,
1.633 - NNMap& right, int& b, int& k, bool what_heur )
1.634 - {
1.635 -
1.636 - Num lev=level[w];
1.637 -
1.638 - Node right_n=right[w];
1.639 - Node left_n=left[w];
1.640 -
1.641 - //unlacing starts
1.642 - if ( g->valid(right_n) ) {
1.643 - if ( g->valid(left_n) ) {
1.644 - right.set(left_n, right_n);
1.645 - left.set(right_n, left_n);
1.646 - } else {
1.647 - level_list[lev]=right_n;
1.648 - left.set(right_n, INVALID);
1.649 - }
1.650 - } else {
1.651 - if ( g->valid(left_n) ) {
1.652 - right.set(left_n, INVALID);
1.653 - } else {
1.654 - level_list[lev]=INVALID;
1.655 - }
1.656 - }
1.657 - //unlacing ends
1.658 -
1.659 - if ( !g->valid(level_list[lev]) ) {
1.660 -
1.661 - //gapping starts
1.662 - for (int i=lev; i!=k ; ) {
1.663 - Node v=level_list[++i];
1.664 - while ( g->valid(v) ) {
1.665 - level.set(v,n);
1.666 - v=right[v];
1.667 - }
1.668 - level_list[i]=INVALID;
1.669 - if ( !what_heur ) {
1.670 - while ( !active[i].empty() ) {
1.671 - active[i].pop(); //FIXME: ezt szebben kene
1.672 - }
1.673 - }
1.674 - }
1.675 -
1.676 - level.set(w,n);
1.677 - b=lev-1;
1.678 - k=b;
1.679 - //gapping ends
1.680 -
1.681 - } else {
1.682 -
1.683 - if ( newlevel == n ) level.set(w,n);
1.684 - else {
1.685 - level.set(w,++newlevel);
1.686 - active[newlevel].push(w);
1.687 - if ( what_heur ) b=newlevel;
1.688 - if ( k < newlevel ) ++k; //now k=newlevel
1.689 - Node first=level_list[newlevel];
1.690 - if ( g->valid(first) ) left.set(first,w);
1.691 - right.set(w,first);
1.692 - left.set(w,INVALID);
1.693 - level_list[newlevel]=w;
1.694 - }
1.695 - }
1.696 -
1.697 - } //relabel
1.698 -
1.699 -
1.700 - template<typename MapGraphWrapper>
1.701 - class DistanceMap {
1.702 - protected:
1.703 - const MapGraphWrapper* g;
1.704 - typename MapGraphWrapper::template NodeMap<int> dist;
1.705 - public:
1.706 - DistanceMap(MapGraphWrapper& _g) : g(&_g), dist(*g, g->nodeNum()) { }
1.707 - void set(const typename MapGraphWrapper::Node& n, int a) {
1.708 - dist.set(n, a);
1.709 - }
1.710 - int operator[](const typename MapGraphWrapper::Node& n) const {
1.711 - return dist[n];
1.712 - }
1.713 - // int get(const typename MapGraphWrapper::Node& n) const {
1.714 - // return dist[n]; }
1.715 - // bool get(const typename MapGraphWrapper::Edge& e) const {
1.716 - // return (dist.get(g->source(e))<dist.get(g->target(e))); }
1.717 - bool operator[](const typename MapGraphWrapper::Edge& e) const {
1.718 - return (dist[g->source(e)]<dist[g->target(e)]);
1.719 - }
1.720 - };
1.721 -
1.722 - };
1.723 -
1.724 -
1.725 - template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.726 - void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase1(FlowEnum fe)
1.727 - {
1.728 -
1.729 - int heur0=(int)(H0*n); //time while running 'bound decrease'
1.730 - int heur1=(int)(H1*n); //time while running 'highest label'
1.731 - int heur=heur1; //starting time interval (#of relabels)
1.732 - int numrelabel=0;
1.733 -
1.734 - bool what_heur=1;
1.735 - //It is 0 in case 'bound decrease' and 1 in case 'highest label'
1.736 -
1.737 - bool end=false;
1.738 - //Needed for 'bound decrease', true means no active nodes are above bound
1.739 - //b.
1.740 -
1.741 - int k=n-2; //bound on the highest level under n containing a node
1.742 - int b=k; //bound on the highest level under n of an active node
1.743 -
1.744 - VecStack active(n);
1.745 -
1.746 - NNMap left(*g, INVALID);
1.747 - NNMap right(*g, INVALID);
1.748 - VecNode level_list(n,INVALID);
1.749 - //List of the nodes in level i<n, set to n.
1.750 -
1.751 - NodeIt v;
1.752 - for(g->first(v); g->valid(v); g->next(v)) level.set(v,n);
1.753 - //setting each node to level n
1.754 -
1.755 - if ( fe == NO_FLOW ) {
1.756 - EdgeIt e;
1.757 - for(g->first(e); g->valid(e); g->next(e)) flow->set(e,0);
1.758 - }
1.759 -
1.760 - switch (fe) { //computing the excess
1.761 - case PRE_FLOW:
1.762 - {
1.763 - NodeIt v;
1.764 - for(g->first(v); g->valid(v); g->next(v)) {
1.765 - Num exc=0;
1.766 -
1.767 - InEdgeIt e;
1.768 - for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e];
1.769 - OutEdgeIt f;
1.770 - for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f];
1.771 -
1.772 - excess.set(v,exc);
1.773 -
1.774 - //putting the active nodes into the stack
1.775 - int lev=level[v];
1.776 - if ( exc > 0 && lev < n && v != t ) active[lev].push(v);
1.777 - }
1.778 - break;
1.779 - }
1.780 - case GEN_FLOW:
1.781 - {
1.782 - NodeIt v;
1.783 - for(g->first(v); g->valid(v); g->next(v)) excess.set(v,0);
1.784 -
1.785 - Num exc=0;
1.786 - InEdgeIt e;
1.787 - for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e];
1.788 - OutEdgeIt f;
1.789 - for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f];
1.790 - excess.set(t,exc);
1.791 - break;
1.792 - }
1.793 - case ZERO_FLOW:
1.794 - case NO_FLOW:
1.795 - {
1.796 - NodeIt v;
1.797 - for(g->first(v); g->valid(v); g->next(v)) excess.set(v,0);
1.798 - break;
1.799 - }
1.800 - }
1.801 -
1.802 - preflowPreproc(fe, active, level_list, left, right);
1.803 - //End of preprocessing
1.804 -
1.805 -
1.806 - //Push/relabel on the highest level active nodes.
1.807 - while ( true ) {
1.808 - if ( b == 0 ) {
1.809 - if ( !what_heur && !end && k > 0 ) {
1.810 - b=k;
1.811 - end=true;
1.812 - } else break;
1.813 - }
1.814 -
1.815 - if ( active[b].empty() ) --b;
1.816 - else {
1.817 - end=false;
1.818 - Node w=active[b].top();
1.819 - active[b].pop();
1.820 - int newlevel=push(w,active);
1.821 - if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list,
1.822 - left, right, b, k, what_heur);
1.823 -
1.824 - ++numrelabel;
1.825 - if ( numrelabel >= heur ) {
1.826 - numrelabel=0;
1.827 - if ( what_heur ) {
1.828 - what_heur=0;
1.829 - heur=heur0;
1.830 - end=false;
1.831 - } else {
1.832 - what_heur=1;
1.833 - heur=heur1;
1.834 - b=k;
1.835 - }
1.836 - }
1.837 - }
1.838 - }
1.839 -
1.840 - status=AFTER_PRE_FLOW_PHASE_1;
1.841 - }
1.842 -
1.843 -
1.844 -
1.845 - template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.846 - void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase2()
1.847 - {
1.848 -
1.849 - int k=n-2; //bound on the highest level under n containing a node
1.850 - int b=k; //bound on the highest level under n of an active node
1.851 -
1.852 - VecStack active(n);
1.853 - level.set(s,0);
1.854 - std::queue<Node> bfs_queue;
1.855 - bfs_queue.push(s);
1.856 -
1.857 - while (!bfs_queue.empty()) {
1.858 -
1.859 - Node v=bfs_queue.front();
1.860 - bfs_queue.pop();
1.861 - int l=level[v]+1;
1.862 -
1.863 - InEdgeIt e;
1.864 - for(g->first(e,v); g->valid(e); g->next(e)) {
1.865 - if ( (*capacity)[e] <= (*flow)[e] ) continue;
1.866 - Node u=g->source(e);
1.867 - if ( level[u] >= n ) {
1.868 - bfs_queue.push(u);
1.869 - level.set(u, l);
1.870 - if ( excess[u] > 0 ) active[l].push(u);
1.871 - }
1.872 - }
1.873 -
1.874 - OutEdgeIt f;
1.875 - for(g->first(f,v); g->valid(f); g->next(f)) {
1.876 - if ( 0 >= (*flow)[f] ) continue;
1.877 - Node u=g->target(f);
1.878 - if ( level[u] >= n ) {
1.879 - bfs_queue.push(u);
1.880 - level.set(u, l);
1.881 - if ( excess[u] > 0 ) active[l].push(u);
1.882 - }
1.883 - }
1.884 - }
1.885 - b=n-2;
1.886 -
1.887 - while ( true ) {
1.888 -
1.889 - if ( b == 0 ) break;
1.890 -
1.891 - if ( active[b].empty() ) --b;
1.892 - else {
1.893 - Node w=active[b].top();
1.894 - active[b].pop();
1.895 - int newlevel=push(w,active);
1.896 -
1.897 - //relabel
1.898 - if ( excess[w] > 0 ) {
1.899 - level.set(w,++newlevel);
1.900 - active[newlevel].push(w);
1.901 - b=newlevel;
1.902 - }
1.903 - } // if stack[b] is nonempty
1.904 - } // while(true)
1.905 -
1.906 - status=AFTER_PRE_FLOW_PHASE_2;
1.907 - }
1.908 -
1.909 -
1.910 -
1.911 - template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.912 - bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath()
1.913 - {
1.914 - ResGW res_graph(*g, *capacity, *flow);
1.915 - bool _augment=false;
1.916 -
1.917 - //ReachedMap level(res_graph);
1.918 - FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.919 - BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
1.920 - bfs.pushAndSetReached(s);
1.921 -
1.922 - typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
1.923 - pred.set(s, INVALID);
1.924 -
1.925 - typename ResGW::template NodeMap<Num> free(res_graph);
1.926 -
1.927 - //searching for augmenting path
1.928 - while ( !bfs.finished() ) {
1.929 - ResGWOutEdgeIt e=bfs;
1.930 - if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
1.931 - Node v=res_graph.source(e);
1.932 - Node w=res_graph.target(e);
1.933 - pred.set(w, e);
1.934 - if (res_graph.valid(pred[v])) {
1.935 - free.set(w, std::min(free[v], res_graph.resCap(e)));
1.936 - } else {
1.937 - free.set(w, res_graph.resCap(e));
1.938 - }
1.939 - if (res_graph.target(e)==t) { _augment=true; break; }
1.940 - }
1.941 -
1.942 - ++bfs;
1.943 - } //end of searching augmenting path
1.944 -
1.945 - if (_augment) {
1.946 - Node n=t;
1.947 - Num augment_value=free[t];
1.948 - while (res_graph.valid(pred[n])) {
1.949 - ResGWEdge e=pred[n];
1.950 - res_graph.augment(e, augment_value);
1.951 - n=res_graph.source(e);
1.952 - }
1.953 - }
1.954 -
1.955 - status=AFTER_AUGMENTING;
1.956 - return _augment;
1.957 - }
1.958 -
1.959 -
1.960 - template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.961 - bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath2()
1.962 - {
1.963 - ResGW res_graph(*g, *capacity, *flow);
1.964 - bool _augment=false;
1.965 -
1.966 - if (status!=AFTER_FAST_AUGMENTING) {
1.967 - FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.968 - number_of_augmentations=1;
1.969 - } else {
1.970 - ++number_of_augmentations;
1.971 - }
1.972 - TrickyReachedMap<ReachedMap>
1.973 - tricky_reached_map(level, number_of_augmentations);
1.974 - //ReachedMap level(res_graph);
1.975 -// FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.976 - BfsIterator<ResGW, TrickyReachedMap<ReachedMap> >
1.977 - bfs(res_graph, tricky_reached_map);
1.978 - bfs.pushAndSetReached(s);
1.979 -
1.980 - typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
1.981 - pred.set(s, INVALID);
1.982 -
1.983 - typename ResGW::template NodeMap<Num> free(res_graph);
1.984 -
1.985 - //searching for augmenting path
1.986 - while ( !bfs.finished() ) {
1.987 - ResGWOutEdgeIt e=bfs;
1.988 - if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
1.989 - Node v=res_graph.source(e);
1.990 - Node w=res_graph.target(e);
1.991 - pred.set(w, e);
1.992 - if (res_graph.valid(pred[v])) {
1.993 - free.set(w, std::min(free[v], res_graph.resCap(e)));
1.994 - } else {
1.995 - free.set(w, res_graph.resCap(e));
1.996 - }
1.997 - if (res_graph.target(e)==t) { _augment=true; break; }
1.998 - }
1.999 -
1.1000 - ++bfs;
1.1001 - } //end of searching augmenting path
1.1002 -
1.1003 - if (_augment) {
1.1004 - Node n=t;
1.1005 - Num augment_value=free[t];
1.1006 - while (res_graph.valid(pred[n])) {
1.1007 - ResGWEdge e=pred[n];
1.1008 - res_graph.augment(e, augment_value);
1.1009 - n=res_graph.source(e);
1.1010 - }
1.1011 - }
1.1012 -
1.1013 - status=AFTER_FAST_AUGMENTING;
1.1014 - return _augment;
1.1015 - }
1.1016 -
1.1017 -
1.1018 - template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.1019 - template<typename MutableGraph>
1.1020 - bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow()
1.1021 - {
1.1022 - typedef MutableGraph MG;
1.1023 - bool _augment=false;
1.1024 -
1.1025 - ResGW res_graph(*g, *capacity, *flow);
1.1026 -
1.1027 - //bfs for distances on the residual graph
1.1028 - //ReachedMap level(res_graph);
1.1029 - FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.1030 - BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
1.1031 - bfs.pushAndSetReached(s);
1.1032 - typename ResGW::template NodeMap<int>
1.1033 - dist(res_graph); //filled up with 0's
1.1034 -
1.1035 - //F will contain the physical copy of the residual graph
1.1036 - //with the set of edges which are on shortest paths
1.1037 - MG F;
1.1038 - typename ResGW::template NodeMap<typename MG::Node>
1.1039 - res_graph_to_F(res_graph);
1.1040 - {
1.1041 - typename ResGW::NodeIt n;
1.1042 - for(res_graph.first(n); res_graph.valid(n); res_graph.next(n)) {
1.1043 - res_graph_to_F.set(n, F.addNode());
1.1044 - }
1.1045 - }
1.1046 -
1.1047 - typename MG::Node sF=res_graph_to_F[s];
1.1048 - typename MG::Node tF=res_graph_to_F[t];
1.1049 - typename MG::template EdgeMap<ResGWEdge> original_edge(F);
1.1050 - typename MG::template EdgeMap<Num> residual_capacity(F);
1.1051 -
1.1052 - while ( !bfs.finished() ) {
1.1053 - ResGWOutEdgeIt e=bfs;
1.1054 - if (res_graph.valid(e)) {
1.1055 - if (bfs.isBNodeNewlyReached()) {
1.1056 - dist.set(res_graph.target(e), dist[res_graph.source(e)]+1);
1.1057 - typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.source(e)],
1.1058 - res_graph_to_F[res_graph.target(e)]);
1.1059 - original_edge.update();
1.1060 - original_edge.set(f, e);
1.1061 - residual_capacity.update();
1.1062 - residual_capacity.set(f, res_graph.resCap(e));
1.1063 - } else {
1.1064 - if (dist[res_graph.target(e)]==(dist[res_graph.source(e)]+1)) {
1.1065 - typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.source(e)],
1.1066 - res_graph_to_F[res_graph.target(e)]);
1.1067 - original_edge.update();
1.1068 - original_edge.set(f, e);
1.1069 - residual_capacity.update();
1.1070 - residual_capacity.set(f, res_graph.resCap(e));
1.1071 - }
1.1072 - }
1.1073 - }
1.1074 - ++bfs;
1.1075 - } //computing distances from s in the residual graph
1.1076 -
1.1077 - bool __augment=true;
1.1078 -
1.1079 - while (__augment) {
1.1080 - __augment=false;
1.1081 - //computing blocking flow with dfs
1.1082 - DfsIterator< MG, typename MG::template NodeMap<bool> > dfs(F);
1.1083 - typename MG::template NodeMap<typename MG::Edge> pred(F);
1.1084 - pred.set(sF, INVALID);
1.1085 - //invalid iterators for sources
1.1086 -
1.1087 - typename MG::template NodeMap<Num> free(F);
1.1088 -
1.1089 - dfs.pushAndSetReached(sF);
1.1090 - while (!dfs.finished()) {
1.1091 - ++dfs;
1.1092 - if (F.valid(/*typename MG::OutEdgeIt*/(dfs))) {
1.1093 - if (dfs.isBNodeNewlyReached()) {
1.1094 - typename MG::Node v=F.aNode(dfs);
1.1095 - typename MG::Node w=F.bNode(dfs);
1.1096 - pred.set(w, dfs);
1.1097 - if (F.valid(pred[v])) {
1.1098 - free.set(w, std::min(free[v], residual_capacity[dfs]));
1.1099 - } else {
1.1100 - free.set(w, residual_capacity[dfs]);
1.1101 - }
1.1102 - if (w==tF) {
1.1103 - __augment=true;
1.1104 - _augment=true;
1.1105 - break;
1.1106 - }
1.1107 -
1.1108 - } else {
1.1109 - F.erase(/*typename MG::OutEdgeIt*/(dfs));
1.1110 - }
1.1111 - }
1.1112 - }
1.1113 -
1.1114 - if (__augment) {
1.1115 - typename MG::Node n=tF;
1.1116 - Num augment_value=free[tF];
1.1117 - while (F.valid(pred[n])) {
1.1118 - typename MG::Edge e=pred[n];
1.1119 - res_graph.augment(original_edge[e], augment_value);
1.1120 - n=F.source(e);
1.1121 - if (residual_capacity[e]==augment_value)
1.1122 - F.erase(e);
1.1123 - else
1.1124 - residual_capacity.set(e, residual_capacity[e]-augment_value);
1.1125 - }
1.1126 - }
1.1127 -
1.1128 - }
1.1129 -
1.1130 - status=AFTER_AUGMENTING;
1.1131 - return _augment;
1.1132 - }
1.1133 -
1.1134 -
1.1135 -
1.1136 -
1.1137 - template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.1138 - bool MaxFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow2()
1.1139 - {
1.1140 - bool _augment=false;
1.1141 -
1.1142 - ResGW res_graph(*g, *capacity, *flow);
1.1143 -
1.1144 - //ReachedMap level(res_graph);
1.1145 - FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.1146 - BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
1.1147 -
1.1148 - bfs.pushAndSetReached(s);
1.1149 - DistanceMap<ResGW> dist(res_graph);
1.1150 - while ( !bfs.finished() ) {
1.1151 - ResGWOutEdgeIt e=bfs;
1.1152 - if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
1.1153 - dist.set(res_graph.target(e), dist[res_graph.source(e)]+1);
1.1154 - }
1.1155 - ++bfs;
1.1156 - } //computing distances from s in the residual graph
1.1157 -
1.1158 - //Subgraph containing the edges on some shortest paths
1.1159 - ConstMap<typename ResGW::Node, bool> true_map(true);
1.1160 - typedef SubGraphWrapper<ResGW, ConstMap<typename ResGW::Node, bool>,
1.1161 - DistanceMap<ResGW> > FilterResGW;
1.1162 - FilterResGW filter_res_graph(res_graph, true_map, dist);
1.1163 -
1.1164 - //Subgraph, which is able to delete edges which are already
1.1165 - //met by the dfs
1.1166 - typename FilterResGW::template NodeMap<typename FilterResGW::OutEdgeIt>
1.1167 - first_out_edges(filter_res_graph);
1.1168 - typename FilterResGW::NodeIt v;
1.1169 - for(filter_res_graph.first(v); filter_res_graph.valid(v);
1.1170 - filter_res_graph.next(v))
1.1171 - {
1.1172 - typename FilterResGW::OutEdgeIt e;
1.1173 - filter_res_graph.first(e, v);
1.1174 - first_out_edges.set(v, e);
1.1175 - }
1.1176 - typedef ErasingFirstGraphWrapper<FilterResGW, typename FilterResGW::
1.1177 - template NodeMap<typename FilterResGW::OutEdgeIt> > ErasingResGW;
1.1178 - ErasingResGW erasing_res_graph(filter_res_graph, first_out_edges);
1.1179 -
1.1180 - bool __augment=true;
1.1181 -
1.1182 - while (__augment) {
1.1183 -
1.1184 - __augment=false;
1.1185 - //computing blocking flow with dfs
1.1186 - DfsIterator< ErasingResGW,
1.1187 - typename ErasingResGW::template NodeMap<bool> >
1.1188 - dfs(erasing_res_graph);
1.1189 - typename ErasingResGW::
1.1190 - template NodeMap<typename ErasingResGW::OutEdgeIt>
1.1191 - pred(erasing_res_graph);
1.1192 - pred.set(s, INVALID);
1.1193 - //invalid iterators for sources
1.1194 -
1.1195 - typename ErasingResGW::template NodeMap<Num>
1.1196 - free1(erasing_res_graph);
1.1197 -
1.1198 - dfs.pushAndSetReached
1.1199 - ///\bug lemon 0.2
1.1200 - (typename ErasingResGW::Node
1.1201 - (typename FilterResGW::Node
1.1202 - (typename ResGW::Node(s)
1.1203 - )
1.1204 - )
1.1205 - );
1.1206 - while (!dfs.finished()) {
1.1207 - ++dfs;
1.1208 - if (erasing_res_graph.valid(typename ErasingResGW::OutEdgeIt(dfs)))
1.1209 - {
1.1210 - if (dfs.isBNodeNewlyReached()) {
1.1211 -
1.1212 - typename ErasingResGW::Node v=erasing_res_graph.aNode(dfs);
1.1213 - typename ErasingResGW::Node w=erasing_res_graph.bNode(dfs);
1.1214 -
1.1215 - pred.set(w, /*typename ErasingResGW::OutEdgeIt*/(dfs));
1.1216 - if (erasing_res_graph.valid(pred[v])) {
1.1217 - free1.set
1.1218 - (w, std::min(free1[v], res_graph.resCap
1.1219 - (typename ErasingResGW::OutEdgeIt(dfs))));
1.1220 - } else {
1.1221 - free1.set
1.1222 - (w, res_graph.resCap
1.1223 - (typename ErasingResGW::OutEdgeIt(dfs)));
1.1224 - }
1.1225 -
1.1226 - if (w==t) {
1.1227 - __augment=true;
1.1228 - _augment=true;
1.1229 - break;
1.1230 - }
1.1231 - } else {
1.1232 - erasing_res_graph.erase(dfs);
1.1233 - }
1.1234 - }
1.1235 - }
1.1236 -
1.1237 - if (__augment) {
1.1238 - typename ErasingResGW::Node
1.1239 - n=typename FilterResGW::Node(typename ResGW::Node(t));
1.1240 - // typename ResGW::NodeMap<Num> a(res_graph);
1.1241 - // typename ResGW::Node b;
1.1242 - // Num j=a[b];
1.1243 - // typename FilterResGW::NodeMap<Num> a1(filter_res_graph);
1.1244 - // typename FilterResGW::Node b1;
1.1245 - // Num j1=a1[b1];
1.1246 - // typename ErasingResGW::NodeMap<Num> a2(erasing_res_graph);
1.1247 - // typename ErasingResGW::Node b2;
1.1248 - // Num j2=a2[b2];
1.1249 - Num augment_value=free1[n];
1.1250 - while (erasing_res_graph.valid(pred[n])) {
1.1251 - typename ErasingResGW::OutEdgeIt e=pred[n];
1.1252 - res_graph.augment(e, augment_value);
1.1253 - n=erasing_res_graph.source(e);
1.1254 - if (res_graph.resCap(e)==0)
1.1255 - erasing_res_graph.erase(e);
1.1256 - }
1.1257 - }
1.1258 -
1.1259 - } //while (__augment)
1.1260 -
1.1261 - status=AFTER_AUGMENTING;
1.1262 - return _augment;
1.1263 - }
1.1264 -
1.1265 -
1.1266 -} //namespace lemon
1.1267 -
1.1268 -#endif //LEMON_MAX_FLOW_H
1.1269 -
1.1270 -
1.1271 -
1.1272 -