1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/work/marci/augmenting_flow.h Tue Aug 17 11:20:16 2004 +0000
1.3 @@ -0,0 +1,1477 @@
1.4 +// -*- C++ -*-
1.5 +#ifndef HUGO_AUGMENTING_FLOW_H
1.6 +#define HUGO_AUGMENTING_FLOW_H
1.7 +
1.8 +#include <vector>
1.9 +#include <queue>
1.10 +#include <stack>
1.11 +#include <iostream>
1.12 +
1.13 +#include <hugo/graph_wrapper.h>
1.14 +#include <bfs_dfs.h>
1.15 +#include <hugo/invalid.h>
1.16 +#include <hugo/maps.h>
1.17 +#include <for_each_macros.h>
1.18 +
1.19 +/// \file
1.20 +/// \brief Maximum flow algorithms.
1.21 +/// \ingroup galgs
1.22 +
1.23 +namespace hugo {
1.24 +
1.25 + /// \addtogroup galgs
1.26 + /// @{
1.27 + ///Maximum flow algorithms class.
1.28 +
1.29 + ///This class provides various algorithms for finding a flow of
1.30 + ///maximum value in a directed graph. The \e source node, the \e
1.31 + ///target node, the \e capacity of the edges and the \e starting \e
1.32 + ///flow value of the edges should be passed to the algorithm through the
1.33 + ///constructor. It is possible to change these quantities using the
1.34 + ///functions \ref resetSource, \ref resetTarget, \ref resetCap and
1.35 + ///\ref resetFlow. Before any subsequent runs of any algorithm of
1.36 + ///the class \ref resetFlow should be called.
1.37 +
1.38 + ///After running an algorithm of the class, the actual flow value
1.39 + ///can be obtained by calling \ref flowValue(). The minimum
1.40 + ///value cut can be written into a \c node map of \c bools by
1.41 + ///calling \ref minCut. (\ref minMinCut and \ref maxMinCut writes
1.42 + ///the inclusionwise minimum and maximum of the minimum value
1.43 + ///cuts, resp.)
1.44 + ///\param Graph The directed graph type the algorithm runs on.
1.45 + ///\param Num The number type of the capacities and the flow values.
1.46 + ///\param CapMap The capacity map type.
1.47 + ///\param FlowMap The flow map type.
1.48 + ///\author Marton Makai, Jacint Szabo
1.49 +// template <typename Graph, typename Num,
1.50 +// typename CapMap=typename Graph::template EdgeMap<Num>,
1.51 +// typename FlowMap=typename Graph::template EdgeMap<Num> >
1.52 +// class MaxFlow {
1.53 +// protected:
1.54 +// typedef typename Graph::Node Node;
1.55 +// typedef typename Graph::NodeIt NodeIt;
1.56 +// typedef typename Graph::EdgeIt EdgeIt;
1.57 +// typedef typename Graph::OutEdgeIt OutEdgeIt;
1.58 +// typedef typename Graph::InEdgeIt InEdgeIt;
1.59 +
1.60 +// typedef typename std::vector<std::stack<Node> > VecStack;
1.61 +// typedef typename Graph::template NodeMap<Node> NNMap;
1.62 +// typedef typename std::vector<Node> VecNode;
1.63 +
1.64 +// const Graph* g;
1.65 +// Node s;
1.66 +// Node t;
1.67 +// const CapMap* capacity;
1.68 +// FlowMap* flow;
1.69 +// int n; //the number of nodes of G
1.70 +// typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
1.71 +// //typedef ExpResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
1.72 +// typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
1.73 +// typedef typename ResGW::Edge ResGWEdge;
1.74 +// //typedef typename ResGW::template NodeMap<bool> ReachedMap;
1.75 +// typedef typename Graph::template NodeMap<int> ReachedMap;
1.76 +
1.77 +
1.78 +// //level works as a bool map in augmenting path algorithms and is
1.79 +// //used by bfs for storing reached information. In preflow, it
1.80 +// //shows the levels of nodes.
1.81 +// ReachedMap level;
1.82 +
1.83 +// //excess is needed only in preflow
1.84 +// typename Graph::template NodeMap<Num> excess;
1.85 +
1.86 +// //fixme
1.87 +// // protected:
1.88 +// // MaxFlow() { }
1.89 +// // void set(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
1.90 +// // FlowMap& _flow)
1.91 +// // {
1.92 +// // g=&_G;
1.93 +// // s=_s;
1.94 +// // t=_t;
1.95 +// // capacity=&_capacity;
1.96 +// // flow=&_flow;
1.97 +// // n=_G.nodeNum;
1.98 +// // level.set (_G); //kellene vmi ilyesmi fv
1.99 +// // excess(_G,0); //itt is
1.100 +// // }
1.101 +
1.102 +// // constants used for heuristics
1.103 +// static const int H0=20;
1.104 +// static const int H1=1;
1.105 +
1.106 +// public:
1.107 +
1.108 +// ///Indicates the property of the starting flow.
1.109 +
1.110 +// ///Indicates the property of the starting flow. The meanings are as follows:
1.111 +// ///- \c ZERO_FLOW: constant zero flow
1.112 +// ///- \c GEN_FLOW: any flow, i.e. the sum of the in-flows equals to
1.113 +// ///the sum of the out-flows in every node except the \e source and
1.114 +// ///the \e target.
1.115 +// ///- \c PRE_FLOW: any preflow, i.e. the sum of the in-flows is at
1.116 +// ///least the sum of the out-flows in every node except the \e source.
1.117 +// ///- \c NO_FLOW: indicates an unspecified edge map. \ref flow will be
1.118 +// ///set to the constant zero flow in the beginning of the algorithm in this case.
1.119 +// enum FlowEnum{
1.120 +// ZERO_FLOW,
1.121 +// GEN_FLOW,
1.122 +// PRE_FLOW,
1.123 +// NO_FLOW
1.124 +// };
1.125 +
1.126 +// enum StatusEnum {
1.127 +// AFTER_NOTHING,
1.128 +// AFTER_AUGMENTING,
1.129 +// AFTER_FAST_AUGMENTING,
1.130 +// AFTER_PRE_FLOW_PHASE_1,
1.131 +// AFTER_PRE_FLOW_PHASE_2
1.132 +// };
1.133 +
1.134 +// /// Don not needle this flag only if necessary.
1.135 +// StatusEnum status;
1.136 +// // int number_of_augmentations;
1.137 +
1.138 +
1.139 +// // template<typename IntMap>
1.140 +// // class TrickyReachedMap {
1.141 +// // protected:
1.142 +// // IntMap* map;
1.143 +// // int* number_of_augmentations;
1.144 +// // public:
1.145 +// // TrickyReachedMap(IntMap& _map, int& _number_of_augmentations) :
1.146 +// // map(&_map), number_of_augmentations(&_number_of_augmentations) { }
1.147 +// // void set(const Node& n, bool b) {
1.148 +// // if (b)
1.149 +// // map->set(n, *number_of_augmentations);
1.150 +// // else
1.151 +// // map->set(n, *number_of_augmentations-1);
1.152 +// // }
1.153 +// // bool operator[](const Node& n) const {
1.154 +// // return (*map)[n]==*number_of_augmentations;
1.155 +// // }
1.156 +// // };
1.157 +
1.158 +// MaxFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
1.159 +// FlowMap& _flow) :
1.160 +// g(&_G), s(_s), t(_t), capacity(&_capacity),
1.161 +// flow(&_flow), n(_G.nodeNum()), level(_G), excess(_G,0),
1.162 +// status(AFTER_NOTHING) { }
1.163 +
1.164 +// ///Runs a maximum flow algorithm.
1.165 +
1.166 +// ///Runs a preflow algorithm, which is the fastest maximum flow
1.167 +// ///algorithm up-to-date. The default for \c fe is ZERO_FLOW.
1.168 +// ///\pre The starting flow must be
1.169 +// /// - a constant zero flow if \c fe is \c ZERO_FLOW,
1.170 +// /// - an arbitary flow if \c fe is \c GEN_FLOW,
1.171 +// /// - an arbitary preflow if \c fe is \c PRE_FLOW,
1.172 +// /// - any map if \c fe is NO_FLOW.
1.173 +// void run(FlowEnum fe=ZERO_FLOW) {
1.174 +// preflow(fe);
1.175 +// }
1.176 +
1.177 +
1.178 +// ///Runs a preflow algorithm.
1.179 +
1.180 +// ///Runs a preflow algorithm. The preflow algorithms provide the
1.181 +// ///fastest way to compute a maximum flow in a directed graph.
1.182 +// ///\pre The starting flow must be
1.183 +// /// - a constant zero flow if \c fe is \c ZERO_FLOW,
1.184 +// /// - an arbitary flow if \c fe is \c GEN_FLOW,
1.185 +// /// - an arbitary preflow if \c fe is \c PRE_FLOW,
1.186 +// /// - any map if \c fe is NO_FLOW.
1.187 +// void preflow(FlowEnum fe) {
1.188 +// preflowPhase1(fe);
1.189 +// preflowPhase2();
1.190 +// }
1.191 +// // Heuristics:
1.192 +// // 2 phase
1.193 +// // gap
1.194 +// // list 'level_list' on the nodes on level i implemented by hand
1.195 +// // stack 'active' on the active nodes on level i
1.196 +// // runs heuristic 'highest label' for H1*n relabels
1.197 +// // runs heuristic 'bound decrease' for H0*n relabels, starts with 'highest label'
1.198 +// // Parameters H0 and H1 are initialized to 20 and 1.
1.199 +
1.200 +// ///Runs the first phase of the preflow algorithm.
1.201 +
1.202 +// ///The preflow algorithm consists of two phases, this method runs the
1.203 +// ///first phase. After the first phase the maximum flow value and a
1.204 +// ///minimum value cut can already be computed, though a maximum flow
1.205 +// ///is net yet obtained. So after calling this method \ref flowValue
1.206 +// ///and \ref actMinCut gives proper results.
1.207 +// ///\warning: \ref minCut, \ref minMinCut and \ref maxMinCut do not
1.208 +// ///give minimum value cuts unless calling \ref preflowPhase2.
1.209 +// ///\pre The starting flow must be
1.210 +// /// - a constant zero flow if \c fe is \c ZERO_FLOW,
1.211 +// /// - an arbitary flow if \c fe is \c GEN_FLOW,
1.212 +// /// - an arbitary preflow if \c fe is \c PRE_FLOW,
1.213 +// /// - any map if \c fe is NO_FLOW.
1.214 +// void preflowPhase1(FlowEnum fe);
1.215 +
1.216 +// ///Runs the second phase of the preflow algorithm.
1.217 +
1.218 +// ///The preflow algorithm consists of two phases, this method runs
1.219 +// ///the second phase. After calling \ref preflowPhase1 and then
1.220 +// ///\ref preflowPhase2 the methods \ref flowValue, \ref minCut,
1.221 +// ///\ref minMinCut and \ref maxMinCut give proper results.
1.222 +// ///\pre \ref preflowPhase1 must be called before.
1.223 +// void preflowPhase2();
1.224 +
1.225 +// /// Returns the maximum value of a flow.
1.226 +
1.227 +// /// Returns the maximum value of a flow, by counting the
1.228 +// /// over-flow of the target node \ref t.
1.229 +// /// It can be called already after running \ref preflowPhase1.
1.230 +// Num flowValue() const {
1.231 +// Num a=0;
1.232 +// FOR_EACH_INC_LOC(InEdgeIt, e, *g, t) a+=(*flow)[e];
1.233 +// FOR_EACH_INC_LOC(OutEdgeIt, e, *g, t) a-=(*flow)[e];
1.234 +// return a;
1.235 +// //marci figyu: excess[t] epp ezt adja preflow 1. fazisa utan
1.236 +// }
1.237 +
1.238 +// ///Returns a minimum value cut after calling \ref preflowPhase1.
1.239 +
1.240 +// ///After the first phase of the preflow algorithm the maximum flow
1.241 +// ///value and a minimum value cut can already be computed. This
1.242 +// ///method can be called after running \ref preflowPhase1 for
1.243 +// ///obtaining a minimum value cut.
1.244 +// /// \warning Gives proper result only right after calling \ref
1.245 +// /// preflowPhase1.
1.246 +// /// \todo We have to make some status variable which shows the
1.247 +// /// actual state
1.248 +// /// of the class. This enables us to determine which methods are valid
1.249 +// /// for MinCut computation
1.250 +// template<typename _CutMap>
1.251 +// void actMinCut(_CutMap& M) const {
1.252 +// NodeIt v;
1.253 +// switch (status) {
1.254 +// case AFTER_PRE_FLOW_PHASE_1:
1.255 +// for(g->first(v); g->valid(v); g->next(v)) {
1.256 +// if (level[v] < n) {
1.257 +// M.set(v, false);
1.258 +// } else {
1.259 +// M.set(v, true);
1.260 +// }
1.261 +// }
1.262 +// break;
1.263 +// case AFTER_PRE_FLOW_PHASE_2:
1.264 +// case AFTER_NOTHING:
1.265 +// case AFTER_AUGMENTING:
1.266 +// case AFTER_FAST_AUGMENTING:
1.267 +// minMinCut(M);
1.268 +// break;
1.269 +// // case AFTER_AUGMENTING:
1.270 +// // for(g->first(v); g->valid(v); g->next(v)) {
1.271 +// // if (level[v]) {
1.272 +// // M.set(v, true);
1.273 +// // } else {
1.274 +// // M.set(v, false);
1.275 +// // }
1.276 +// // }
1.277 +// // break;
1.278 +// // case AFTER_FAST_AUGMENTING:
1.279 +// // for(g->first(v); g->valid(v); g->next(v)) {
1.280 +// // if (level[v]==number_of_augmentations) {
1.281 +// // M.set(v, true);
1.282 +// // } else {
1.283 +// // M.set(v, false);
1.284 +// // }
1.285 +// // }
1.286 +// // break;
1.287 +// }
1.288 +// }
1.289 +
1.290 +// ///Returns the inclusionwise minimum of the minimum value cuts.
1.291 +
1.292 +// ///Sets \c M to the characteristic vector of the minimum value cut
1.293 +// ///which is inclusionwise minimum. It is computed by processing
1.294 +// ///a bfs from the source node \c s in the residual graph.
1.295 +// ///\pre M should be a node map of bools initialized to false.
1.296 +// ///\pre \c flow must be a maximum flow.
1.297 +// template<typename _CutMap>
1.298 +// void minMinCut(_CutMap& M) const {
1.299 +// std::queue<Node> queue;
1.300 +
1.301 +// M.set(s,true);
1.302 +// queue.push(s);
1.303 +
1.304 +// while (!queue.empty()) {
1.305 +// Node w=queue.front();
1.306 +// queue.pop();
1.307 +
1.308 +// OutEdgeIt e;
1.309 +// for(g->first(e,w) ; g->valid(e); g->next(e)) {
1.310 +// Node v=g->head(e);
1.311 +// if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
1.312 +// queue.push(v);
1.313 +// M.set(v, true);
1.314 +// }
1.315 +// }
1.316 +
1.317 +// InEdgeIt f;
1.318 +// for(g->first(f,w) ; g->valid(f); g->next(f)) {
1.319 +// Node v=g->tail(f);
1.320 +// if (!M[v] && (*flow)[f] > 0 ) {
1.321 +// queue.push(v);
1.322 +// M.set(v, true);
1.323 +// }
1.324 +// }
1.325 +// }
1.326 +// }
1.327 +
1.328 +// ///Returns the inclusionwise maximum of the minimum value cuts.
1.329 +
1.330 +// ///Sets \c M to the characteristic vector of the minimum value cut
1.331 +// ///which is inclusionwise maximum. It is computed by processing a
1.332 +// ///backward bfs from the target node \c t in the residual graph.
1.333 +// ///\pre M should be a node map of bools initialized to false.
1.334 +// ///\pre \c flow must be a maximum flow.
1.335 +// template<typename _CutMap>
1.336 +// void maxMinCut(_CutMap& M) const {
1.337 +
1.338 +// NodeIt v;
1.339 +// for(g->first(v) ; g->valid(v); g->next(v)) {
1.340 +// M.set(v, true);
1.341 +// }
1.342 +
1.343 +// std::queue<Node> queue;
1.344 +
1.345 +// M.set(t,false);
1.346 +// queue.push(t);
1.347 +
1.348 +// while (!queue.empty()) {
1.349 +// Node w=queue.front();
1.350 +// queue.pop();
1.351 +
1.352 +// InEdgeIt e;
1.353 +// for(g->first(e,w) ; g->valid(e); g->next(e)) {
1.354 +// Node v=g->tail(e);
1.355 +// if (M[v] && (*flow)[e] < (*capacity)[e] ) {
1.356 +// queue.push(v);
1.357 +// M.set(v, false);
1.358 +// }
1.359 +// }
1.360 +
1.361 +// OutEdgeIt f;
1.362 +// for(g->first(f,w) ; g->valid(f); g->next(f)) {
1.363 +// Node v=g->head(f);
1.364 +// if (M[v] && (*flow)[f] > 0 ) {
1.365 +// queue.push(v);
1.366 +// M.set(v, false);
1.367 +// }
1.368 +// }
1.369 +// }
1.370 +// }
1.371 +
1.372 +// ///Returns a minimum value cut.
1.373 +
1.374 +// ///Sets \c M to the characteristic vector of a minimum value cut.
1.375 +// ///\pre M should be a node map of bools initialized to false.
1.376 +// ///\pre \c flow must be a maximum flow.
1.377 +// template<typename CutMap>
1.378 +// void minCut(CutMap& M) const { minMinCut(M); }
1.379 +
1.380 +// ///Resets the source node to \c _s.
1.381 +
1.382 +// ///Resets the source node to \c _s.
1.383 +// ///
1.384 +// void resetSource(Node _s) { s=_s; status=AFTER_NOTHING; }
1.385 +
1.386 +// ///Resets the target node to \c _t.
1.387 +
1.388 +// ///Resets the target node to \c _t.
1.389 +// ///
1.390 +// void resetTarget(Node _t) { t=_t; status=AFTER_NOTHING; }
1.391 +
1.392 +// /// Resets the edge map of the capacities to _cap.
1.393 +
1.394 +// /// Resets the edge map of the capacities to _cap.
1.395 +// ///
1.396 +// void resetCap(const CapMap& _cap) { capacity=&_cap; status=AFTER_NOTHING; }
1.397 +
1.398 +// /// Resets the edge map of the flows to _flow.
1.399 +
1.400 +// /// Resets the edge map of the flows to _flow.
1.401 +// ///
1.402 +// void resetFlow(FlowMap& _flow) { flow=&_flow; status=AFTER_NOTHING; }
1.403 +
1.404 +
1.405 +// private:
1.406 +
1.407 +// int push(Node w, VecStack& active) {
1.408 +
1.409 +// int lev=level[w];
1.410 +// Num exc=excess[w];
1.411 +// int newlevel=n; //bound on the next level of w
1.412 +
1.413 +// OutEdgeIt e;
1.414 +// for(g->first(e,w); g->valid(e); g->next(e)) {
1.415 +
1.416 +// if ( (*flow)[e] >= (*capacity)[e] ) continue;
1.417 +// Node v=g->head(e);
1.418 +
1.419 +// if( lev > level[v] ) { //Push is allowed now
1.420 +
1.421 +// if ( excess[v]<=0 && v!=t && v!=s ) {
1.422 +// int lev_v=level[v];
1.423 +// active[lev_v].push(v);
1.424 +// }
1.425 +
1.426 +// Num cap=(*capacity)[e];
1.427 +// Num flo=(*flow)[e];
1.428 +// Num remcap=cap-flo;
1.429 +
1.430 +// if ( remcap >= exc ) { //A nonsaturating push.
1.431 +
1.432 +// flow->set(e, flo+exc);
1.433 +// excess.set(v, excess[v]+exc);
1.434 +// exc=0;
1.435 +// break;
1.436 +
1.437 +// } else { //A saturating push.
1.438 +// flow->set(e, cap);
1.439 +// excess.set(v, excess[v]+remcap);
1.440 +// exc-=remcap;
1.441 +// }
1.442 +// } else if ( newlevel > level[v] ) newlevel = level[v];
1.443 +// } //for out edges wv
1.444 +
1.445 +// if ( exc > 0 ) {
1.446 +// InEdgeIt e;
1.447 +// for(g->first(e,w); g->valid(e); g->next(e)) {
1.448 +
1.449 +// if( (*flow)[e] <= 0 ) continue;
1.450 +// Node v=g->tail(e);
1.451 +
1.452 +// if( lev > level[v] ) { //Push is allowed now
1.453 +
1.454 +// if ( excess[v]<=0 && v!=t && v!=s ) {
1.455 +// int lev_v=level[v];
1.456 +// active[lev_v].push(v);
1.457 +// }
1.458 +
1.459 +// Num flo=(*flow)[e];
1.460 +
1.461 +// if ( flo >= exc ) { //A nonsaturating push.
1.462 +
1.463 +// flow->set(e, flo-exc);
1.464 +// excess.set(v, excess[v]+exc);
1.465 +// exc=0;
1.466 +// break;
1.467 +// } else { //A saturating push.
1.468 +
1.469 +// excess.set(v, excess[v]+flo);
1.470 +// exc-=flo;
1.471 +// flow->set(e,0);
1.472 +// }
1.473 +// } else if ( newlevel > level[v] ) newlevel = level[v];
1.474 +// } //for in edges vw
1.475 +
1.476 +// } // if w still has excess after the out edge for cycle
1.477 +
1.478 +// excess.set(w, exc);
1.479 +
1.480 +// return newlevel;
1.481 +// }
1.482 +
1.483 +
1.484 +// void preflowPreproc(FlowEnum fe, VecStack& active,
1.485 +// VecNode& level_list, NNMap& left, NNMap& right)
1.486 +// {
1.487 +// std::queue<Node> bfs_queue;
1.488 +
1.489 +// switch (fe) {
1.490 +// case NO_FLOW: //flow is already set to const zero in this case
1.491 +// case ZERO_FLOW:
1.492 +// {
1.493 +// //Reverse_bfs from t, to find the starting level.
1.494 +// level.set(t,0);
1.495 +// bfs_queue.push(t);
1.496 +
1.497 +// while (!bfs_queue.empty()) {
1.498 +
1.499 +// Node v=bfs_queue.front();
1.500 +// bfs_queue.pop();
1.501 +// int l=level[v]+1;
1.502 +
1.503 +// InEdgeIt e;
1.504 +// for(g->first(e,v); g->valid(e); g->next(e)) {
1.505 +// Node w=g->tail(e);
1.506 +// if ( level[w] == n && w != s ) {
1.507 +// bfs_queue.push(w);
1.508 +// Node first=level_list[l];
1.509 +// if ( g->valid(first) ) left.set(first,w);
1.510 +// right.set(w,first);
1.511 +// level_list[l]=w;
1.512 +// level.set(w, l);
1.513 +// }
1.514 +// }
1.515 +// }
1.516 +
1.517 +// //the starting flow
1.518 +// OutEdgeIt e;
1.519 +// for(g->first(e,s); g->valid(e); g->next(e))
1.520 +// {
1.521 +// Num c=(*capacity)[e];
1.522 +// if ( c <= 0 ) continue;
1.523 +// Node w=g->head(e);
1.524 +// if ( level[w] < n ) {
1.525 +// if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
1.526 +// flow->set(e, c);
1.527 +// excess.set(w, excess[w]+c);
1.528 +// }
1.529 +// }
1.530 +// break;
1.531 +// }
1.532 +
1.533 +// case GEN_FLOW:
1.534 +// case PRE_FLOW:
1.535 +// {
1.536 +// //Reverse_bfs from t in the residual graph,
1.537 +// //to find the starting level.
1.538 +// level.set(t,0);
1.539 +// bfs_queue.push(t);
1.540 +
1.541 +// while (!bfs_queue.empty()) {
1.542 +
1.543 +// Node v=bfs_queue.front();
1.544 +// bfs_queue.pop();
1.545 +// int l=level[v]+1;
1.546 +
1.547 +// InEdgeIt e;
1.548 +// for(g->first(e,v); g->valid(e); g->next(e)) {
1.549 +// if ( (*capacity)[e] <= (*flow)[e] ) continue;
1.550 +// Node w=g->tail(e);
1.551 +// if ( level[w] == n && w != s ) {
1.552 +// bfs_queue.push(w);
1.553 +// Node first=level_list[l];
1.554 +// if ( g->valid(first) ) left.set(first,w);
1.555 +// right.set(w,first);
1.556 +// level_list[l]=w;
1.557 +// level.set(w, l);
1.558 +// }
1.559 +// }
1.560 +
1.561 +// OutEdgeIt f;
1.562 +// for(g->first(f,v); g->valid(f); g->next(f)) {
1.563 +// if ( 0 >= (*flow)[f] ) continue;
1.564 +// Node w=g->head(f);
1.565 +// if ( level[w] == n && w != s ) {
1.566 +// bfs_queue.push(w);
1.567 +// Node first=level_list[l];
1.568 +// if ( g->valid(first) ) left.set(first,w);
1.569 +// right.set(w,first);
1.570 +// level_list[l]=w;
1.571 +// level.set(w, l);
1.572 +// }
1.573 +// }
1.574 +// }
1.575 +
1.576 +
1.577 +// //the starting flow
1.578 +// OutEdgeIt e;
1.579 +// for(g->first(e,s); g->valid(e); g->next(e))
1.580 +// {
1.581 +// Num rem=(*capacity)[e]-(*flow)[e];
1.582 +// if ( rem <= 0 ) continue;
1.583 +// Node w=g->head(e);
1.584 +// if ( level[w] < n ) {
1.585 +// if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
1.586 +// flow->set(e, (*capacity)[e]);
1.587 +// excess.set(w, excess[w]+rem);
1.588 +// }
1.589 +// }
1.590 +
1.591 +// InEdgeIt f;
1.592 +// for(g->first(f,s); g->valid(f); g->next(f))
1.593 +// {
1.594 +// if ( (*flow)[f] <= 0 ) continue;
1.595 +// Node w=g->tail(f);
1.596 +// if ( level[w] < n ) {
1.597 +// if ( excess[w] <= 0 && w!=t ) active[level[w]].push(w);
1.598 +// excess.set(w, excess[w]+(*flow)[f]);
1.599 +// flow->set(f, 0);
1.600 +// }
1.601 +// }
1.602 +// break;
1.603 +// } //case PRE_FLOW
1.604 +// }
1.605 +// } //preflowPreproc
1.606 +
1.607 +
1.608 +
1.609 +// void relabel(Node w, int newlevel, VecStack& active,
1.610 +// VecNode& level_list, NNMap& left,
1.611 +// NNMap& right, int& b, int& k, bool what_heur )
1.612 +// {
1.613 +
1.614 +// //FIXME jacint: ez mitol num
1.615 +// // Num lev=level[w];
1.616 +// int lev=level[w];
1.617 +
1.618 +// Node right_n=right[w];
1.619 +// Node left_n=left[w];
1.620 +
1.621 +// //unlacing starts
1.622 +// if ( g->valid(right_n) ) {
1.623 +// if ( g->valid(left_n) ) {
1.624 +// right.set(left_n, right_n);
1.625 +// left.set(right_n, left_n);
1.626 +// } else {
1.627 +// level_list[lev]=right_n;
1.628 +// left.set(right_n, INVALID);
1.629 +// }
1.630 +// } else {
1.631 +// if ( g->valid(left_n) ) {
1.632 +// right.set(left_n, INVALID);
1.633 +// } else {
1.634 +// level_list[lev]=INVALID;
1.635 +// }
1.636 +// }
1.637 +// //unlacing ends
1.638 +
1.639 +// if ( !g->valid(level_list[lev]) ) {
1.640 +
1.641 +// //gapping starts
1.642 +// for (int i=lev; i!=k ; ) {
1.643 +// Node v=level_list[++i];
1.644 +// while ( g->valid(v) ) {
1.645 +// level.set(v,n);
1.646 +// v=right[v];
1.647 +// }
1.648 +// level_list[i]=INVALID;
1.649 +// if ( !what_heur ) {
1.650 +// while ( !active[i].empty() ) {
1.651 +// active[i].pop(); //FIXME: ezt szebben kene
1.652 +// }
1.653 +// }
1.654 +// }
1.655 +
1.656 +// level.set(w,n);
1.657 +// b=lev-1;
1.658 +// k=b;
1.659 +// //gapping ends
1.660 +
1.661 +// } else {
1.662 +
1.663 +// if ( newlevel == n ) level.set(w,n);
1.664 +// else {
1.665 +// level.set(w,++newlevel);
1.666 +// active[newlevel].push(w);
1.667 +// if ( what_heur ) b=newlevel;
1.668 +// if ( k < newlevel ) ++k; //now k=newlevel
1.669 +// Node first=level_list[newlevel];
1.670 +// if ( g->valid(first) ) left.set(first,w);
1.671 +// right.set(w,first);
1.672 +// left.set(w,INVALID);
1.673 +// level_list[newlevel]=w;
1.674 +// }
1.675 +// }
1.676 +
1.677 +// } //relabel
1.678 +
1.679 +// };
1.680 +
1.681 +
1.682 +
1.683 +// template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.684 +// void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase1(FlowEnum fe)
1.685 +// {
1.686 +
1.687 +// int heur0=(int)(H0*n); //time while running 'bound decrease'
1.688 +// int heur1=(int)(H1*n); //time while running 'highest label'
1.689 +// int heur=heur1; //starting time interval (#of relabels)
1.690 +// int numrelabel=0;
1.691 +
1.692 +// bool what_heur=1;
1.693 +// //It is 0 in case 'bound decrease' and 1 in case 'highest label'
1.694 +
1.695 +// bool end=false;
1.696 +// //Needed for 'bound decrease', true means no active nodes are above bound
1.697 +// //b.
1.698 +
1.699 +// int k=n-2; //bound on the highest level under n containing a node
1.700 +// int b=k; //bound on the highest level under n of an active node
1.701 +
1.702 +// VecStack active(n);
1.703 +
1.704 +// NNMap left(*g, INVALID);
1.705 +// NNMap right(*g, INVALID);
1.706 +// VecNode level_list(n,INVALID);
1.707 +// //List of the nodes in level i<n, set to n.
1.708 +
1.709 +// NodeIt v;
1.710 +// for(g->first(v); g->valid(v); g->next(v)) level.set(v,n);
1.711 +// //setting each node to level n
1.712 +
1.713 +// if ( fe == NO_FLOW ) {
1.714 +// EdgeIt e;
1.715 +// for(g->first(e); g->valid(e); g->next(e)) flow->set(e,0);
1.716 +// }
1.717 +
1.718 +// switch (fe) { //computing the excess
1.719 +// case PRE_FLOW:
1.720 +// {
1.721 +// NodeIt v;
1.722 +// for(g->first(v); g->valid(v); g->next(v)) {
1.723 +// Num exc=0;
1.724 +
1.725 +// InEdgeIt e;
1.726 +// for(g->first(e,v); g->valid(e); g->next(e)) exc+=(*flow)[e];
1.727 +// OutEdgeIt f;
1.728 +// for(g->first(f,v); g->valid(f); g->next(f)) exc-=(*flow)[f];
1.729 +
1.730 +// excess.set(v,exc);
1.731 +
1.732 +// //putting the active nodes into the stack
1.733 +// int lev=level[v];
1.734 +// if ( exc > 0 && lev < n && v != t ) active[lev].push(v);
1.735 +// }
1.736 +// break;
1.737 +// }
1.738 +// case GEN_FLOW:
1.739 +// {
1.740 +// NodeIt v;
1.741 +// for(g->first(v); g->valid(v); g->next(v)) excess.set(v,0);
1.742 +
1.743 +// Num exc=0;
1.744 +// InEdgeIt e;
1.745 +// for(g->first(e,t); g->valid(e); g->next(e)) exc+=(*flow)[e];
1.746 +// OutEdgeIt f;
1.747 +// for(g->first(f,t); g->valid(f); g->next(f)) exc-=(*flow)[f];
1.748 +// excess.set(t,exc);
1.749 +// break;
1.750 +// }
1.751 +// case ZERO_FLOW:
1.752 +// case NO_FLOW:
1.753 +// {
1.754 +// NodeIt v;
1.755 +// for(g->first(v); g->valid(v); g->next(v)) excess.set(v,0);
1.756 +// break;
1.757 +// }
1.758 +// }
1.759 +
1.760 +// preflowPreproc(fe, active, level_list, left, right);
1.761 +// //End of preprocessing
1.762 +
1.763 +
1.764 +// //Push/relabel on the highest level active nodes.
1.765 +// while ( true ) {
1.766 +// if ( b == 0 ) {
1.767 +// if ( !what_heur && !end && k > 0 ) {
1.768 +// b=k;
1.769 +// end=true;
1.770 +// } else break;
1.771 +// }
1.772 +
1.773 +// if ( active[b].empty() ) --b;
1.774 +// else {
1.775 +// end=false;
1.776 +// Node w=active[b].top();
1.777 +// active[b].pop();
1.778 +// int newlevel=push(w,active);
1.779 +// if ( excess[w] > 0 ) relabel(w, newlevel, active, level_list,
1.780 +// left, right, b, k, what_heur);
1.781 +
1.782 +// ++numrelabel;
1.783 +// if ( numrelabel >= heur ) {
1.784 +// numrelabel=0;
1.785 +// if ( what_heur ) {
1.786 +// what_heur=0;
1.787 +// heur=heur0;
1.788 +// end=false;
1.789 +// } else {
1.790 +// what_heur=1;
1.791 +// heur=heur1;
1.792 +// b=k;
1.793 +// }
1.794 +// }
1.795 +// }
1.796 +// }
1.797 +
1.798 +// status=AFTER_PRE_FLOW_PHASE_1;
1.799 +// }
1.800 +
1.801 +
1.802 +
1.803 +// template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.804 +// void MaxFlow<Graph, Num, CapMap, FlowMap>::preflowPhase2()
1.805 +// {
1.806 +
1.807 +// int k=n-2; //bound on the highest level under n containing a node
1.808 +// int b=k; //bound on the highest level under n of an active node
1.809 +
1.810 +// VecStack active(n);
1.811 +// level.set(s,0);
1.812 +// std::queue<Node> bfs_queue;
1.813 +// bfs_queue.push(s);
1.814 +
1.815 +// while (!bfs_queue.empty()) {
1.816 +
1.817 +// Node v=bfs_queue.front();
1.818 +// bfs_queue.pop();
1.819 +// int l=level[v]+1;
1.820 +
1.821 +// InEdgeIt e;
1.822 +// for(g->first(e,v); g->valid(e); g->next(e)) {
1.823 +// if ( (*capacity)[e] <= (*flow)[e] ) continue;
1.824 +// Node u=g->tail(e);
1.825 +// if ( level[u] >= n ) {
1.826 +// bfs_queue.push(u);
1.827 +// level.set(u, l);
1.828 +// if ( excess[u] > 0 ) active[l].push(u);
1.829 +// }
1.830 +// }
1.831 +
1.832 +// OutEdgeIt f;
1.833 +// for(g->first(f,v); g->valid(f); g->next(f)) {
1.834 +// if ( 0 >= (*flow)[f] ) continue;
1.835 +// Node u=g->head(f);
1.836 +// if ( level[u] >= n ) {
1.837 +// bfs_queue.push(u);
1.838 +// level.set(u, l);
1.839 +// if ( excess[u] > 0 ) active[l].push(u);
1.840 +// }
1.841 +// }
1.842 +// }
1.843 +// b=n-2;
1.844 +
1.845 +// while ( true ) {
1.846 +
1.847 +// if ( b == 0 ) break;
1.848 +
1.849 +// if ( active[b].empty() ) --b;
1.850 +// else {
1.851 +// Node w=active[b].top();
1.852 +// active[b].pop();
1.853 +// int newlevel=push(w,active);
1.854 +
1.855 +// //relabel
1.856 +// if ( excess[w] > 0 ) {
1.857 +// level.set(w,++newlevel);
1.858 +// active[newlevel].push(w);
1.859 +// b=newlevel;
1.860 +// }
1.861 +// } // if stack[b] is nonempty
1.862 +// } // while(true)
1.863 +
1.864 +// status=AFTER_PRE_FLOW_PHASE_2;
1.865 +// }
1.866 +
1.867 +
1.868 + template <typename Graph, typename Num,
1.869 + typename CapMap=typename Graph::template EdgeMap<Num>,
1.870 + typename FlowMap=typename Graph::template EdgeMap<Num> >
1.871 + class AugmentingFlow {
1.872 + protected:
1.873 + typedef typename Graph::Node Node;
1.874 + typedef typename Graph::NodeIt NodeIt;
1.875 + typedef typename Graph::EdgeIt EdgeIt;
1.876 + typedef typename Graph::OutEdgeIt OutEdgeIt;
1.877 + typedef typename Graph::InEdgeIt InEdgeIt;
1.878 +
1.879 +// typedef typename std::vector<std::stack<Node> > VecStack;
1.880 +// typedef typename Graph::template NodeMap<Node> NNMap;
1.881 +// typedef typename std::vector<Node> VecNode;
1.882 +
1.883 + const Graph* g;
1.884 + Node s;
1.885 + Node t;
1.886 + const CapMap* capacity;
1.887 + FlowMap* flow;
1.888 +// int n; //the number of nodes of G
1.889 + typedef ResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
1.890 + //typedef ExpResGraphWrapper<const Graph, Num, CapMap, FlowMap> ResGW;
1.891 + typedef typename ResGW::OutEdgeIt ResGWOutEdgeIt;
1.892 + typedef typename ResGW::Edge ResGWEdge;
1.893 + //typedef typename ResGW::template NodeMap<bool> ReachedMap;
1.894 + typedef typename Graph::template NodeMap<int> ReachedMap;
1.895 +
1.896 +
1.897 + //level works as a bool map in augmenting path algorithms and is
1.898 + //used by bfs for storing reached information. In preflow, it
1.899 + //shows the levels of nodes.
1.900 + ReachedMap level;
1.901 +
1.902 + //excess is needed only in preflow
1.903 +// typename Graph::template NodeMap<Num> excess;
1.904 +
1.905 + //fixme
1.906 +// protected:
1.907 + // MaxFlow() { }
1.908 + // void set(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
1.909 + // FlowMap& _flow)
1.910 + // {
1.911 + // g=&_G;
1.912 + // s=_s;
1.913 + // t=_t;
1.914 + // capacity=&_capacity;
1.915 + // flow=&_flow;
1.916 + // n=_G.nodeNum;
1.917 + // level.set (_G); //kellene vmi ilyesmi fv
1.918 + // excess(_G,0); //itt is
1.919 + // }
1.920 +
1.921 + // constants used for heuristics
1.922 +// static const int H0=20;
1.923 +// static const int H1=1;
1.924 +
1.925 + public:
1.926 +
1.927 + ///Indicates the property of the starting flow.
1.928 +
1.929 + ///Indicates the property of the starting flow. The meanings are as follows:
1.930 + ///- \c ZERO_FLOW: constant zero flow
1.931 + ///- \c GEN_FLOW: any flow, i.e. the sum of the in-flows equals to
1.932 + ///the sum of the out-flows in every node except the \e source and
1.933 + ///the \e target.
1.934 + ///- \c PRE_FLOW: any preflow, i.e. the sum of the in-flows is at
1.935 + ///least the sum of the out-flows in every node except the \e source.
1.936 + ///- \c NO_FLOW: indicates an unspecified edge map. \ref flow will be
1.937 + ///set to the constant zero flow in the beginning of the algorithm in this case.
1.938 + enum FlowEnum{
1.939 + ZERO_FLOW,
1.940 + GEN_FLOW,
1.941 + PRE_FLOW,
1.942 + NO_FLOW
1.943 + };
1.944 +
1.945 + enum StatusEnum {
1.946 + AFTER_NOTHING,
1.947 + AFTER_AUGMENTING,
1.948 + AFTER_FAST_AUGMENTING,
1.949 + AFTER_PRE_FLOW_PHASE_1,
1.950 + AFTER_PRE_FLOW_PHASE_2
1.951 + };
1.952 +
1.953 + /// Don not needle this flag only if necessary.
1.954 + StatusEnum status;
1.955 + int number_of_augmentations;
1.956 +
1.957 +
1.958 + template<typename IntMap>
1.959 + class TrickyReachedMap {
1.960 + protected:
1.961 + IntMap* map;
1.962 + int* number_of_augmentations;
1.963 + public:
1.964 + TrickyReachedMap(IntMap& _map, int& _number_of_augmentations) :
1.965 + map(&_map), number_of_augmentations(&_number_of_augmentations) { }
1.966 + void set(const Node& n, bool b) {
1.967 + if (b)
1.968 + map->set(n, *number_of_augmentations);
1.969 + else
1.970 + map->set(n, *number_of_augmentations-1);
1.971 + }
1.972 + bool operator[](const Node& n) const {
1.973 + return (*map)[n]==*number_of_augmentations;
1.974 + }
1.975 + };
1.976 +
1.977 + AugmentingFlow(const Graph& _G, Node _s, Node _t, const CapMap& _capacity,
1.978 + FlowMap& _flow) :
1.979 + g(&_G), s(_s), t(_t), capacity(&_capacity),
1.980 + flow(&_flow), //n(_G.nodeNum()),
1.981 + level(_G), //excess(_G,0),
1.982 + status(AFTER_NOTHING), number_of_augmentations(0) { }
1.983 +
1.984 + /// Starting from a flow, this method searches for an augmenting path
1.985 + /// according to the Edmonds-Karp algorithm
1.986 + /// and augments the flow on if any.
1.987 + /// The return value shows if the augmentation was succesful.
1.988 + bool augmentOnShortestPath();
1.989 + bool augmentOnShortestPath2();
1.990 +
1.991 + /// Starting from a flow, this method searches for an augmenting blocking
1.992 + /// flow according to Dinits' algorithm and augments the flow on if any.
1.993 + /// The blocking flow is computed in a physically constructed
1.994 + /// residual graph of type \c Mutablegraph.
1.995 + /// The return value show sif the augmentation was succesful.
1.996 + template<typename MutableGraph> bool augmentOnBlockingFlow();
1.997 +
1.998 + /// The same as \c augmentOnBlockingFlow<MutableGraph> but the
1.999 + /// residual graph is not constructed physically.
1.1000 + /// The return value shows if the augmentation was succesful.
1.1001 + bool augmentOnBlockingFlow2();
1.1002 +
1.1003 + template<typename _CutMap>
1.1004 + void actMinCut(_CutMap& M) const {
1.1005 + NodeIt v;
1.1006 + switch (status) {
1.1007 + case AFTER_PRE_FLOW_PHASE_1:
1.1008 +// std::cout << "AFTER_PRE_FLOW_PHASE_1" << std::endl;
1.1009 +// for(g->first(v); g->valid(v); g->next(v)) {
1.1010 +// if (level[v] < n) {
1.1011 +// M.set(v, false);
1.1012 +// } else {
1.1013 +// M.set(v, true);
1.1014 +// }
1.1015 +// }
1.1016 + break;
1.1017 + case AFTER_PRE_FLOW_PHASE_2:
1.1018 +// std::cout << "AFTER_PRE_FLOW_PHASE_2" << std::endl;
1.1019 + break;
1.1020 + case AFTER_NOTHING:
1.1021 +// std::cout << "AFTER_NOTHING" << std::endl;
1.1022 + minMinCut(M);
1.1023 + break;
1.1024 + case AFTER_AUGMENTING:
1.1025 +// std::cout << "AFTER_AUGMENTING" << std::endl;
1.1026 + for(g->first(v); g->valid(v); g->next(v)) {
1.1027 + if (level[v]) {
1.1028 + M.set(v, true);
1.1029 + } else {
1.1030 + M.set(v, false);
1.1031 + }
1.1032 + }
1.1033 + break;
1.1034 + case AFTER_FAST_AUGMENTING:
1.1035 +// std::cout << "AFTER_FAST_AUGMENTING" << std::endl;
1.1036 + for(g->first(v); g->valid(v); g->next(v)) {
1.1037 + if (level[v]==number_of_augmentations) {
1.1038 + M.set(v, true);
1.1039 + } else {
1.1040 + M.set(v, false);
1.1041 + }
1.1042 + }
1.1043 + break;
1.1044 + }
1.1045 + }
1.1046 +
1.1047 + template<typename _CutMap>
1.1048 + void minMinCut(_CutMap& M) const {
1.1049 + std::queue<Node> queue;
1.1050 +
1.1051 + M.set(s,true);
1.1052 + queue.push(s);
1.1053 +
1.1054 + while (!queue.empty()) {
1.1055 + Node w=queue.front();
1.1056 + queue.pop();
1.1057 +
1.1058 + OutEdgeIt e;
1.1059 + for(g->first(e,w) ; g->valid(e); g->next(e)) {
1.1060 + Node v=g->head(e);
1.1061 + if (!M[v] && (*flow)[e] < (*capacity)[e] ) {
1.1062 + queue.push(v);
1.1063 + M.set(v, true);
1.1064 + }
1.1065 + }
1.1066 +
1.1067 + InEdgeIt f;
1.1068 + for(g->first(f,w) ; g->valid(f); g->next(f)) {
1.1069 + Node v=g->tail(f);
1.1070 + if (!M[v] && (*flow)[f] > 0 ) {
1.1071 + queue.push(v);
1.1072 + M.set(v, true);
1.1073 + }
1.1074 + }
1.1075 + }
1.1076 + }
1.1077 +
1.1078 + template<typename _CutMap>
1.1079 + void minMinCut2(_CutMap& M) const {
1.1080 + ResGW res_graph(*g, *capacity, *flow);
1.1081 + BfsIterator<ResGW, _CutMap> bfs(res_graph, M);
1.1082 + bfs.pushAndSetReached(s);
1.1083 + while (!bfs.finished()) ++bfs;
1.1084 + }
1.1085 +
1.1086 + Num flowValue() const {
1.1087 + Num a=0;
1.1088 + FOR_EACH_INC_LOC(InEdgeIt, e, *g, t) a+=(*flow)[e];
1.1089 + FOR_EACH_INC_LOC(OutEdgeIt, e, *g, t) a-=(*flow)[e];
1.1090 + return a;
1.1091 + //marci figyu: excess[t] epp ezt adja preflow 1. fazisa utan
1.1092 + }
1.1093 +
1.1094 + template<typename MapGraphWrapper>
1.1095 + class DistanceMap {
1.1096 + protected:
1.1097 + const MapGraphWrapper* g;
1.1098 + typename MapGraphWrapper::template NodeMap<int> dist;
1.1099 + public:
1.1100 + DistanceMap(MapGraphWrapper& _g) : g(&_g), dist(*g, g->nodeNum()) { }
1.1101 + void set(const typename MapGraphWrapper::Node& n, int a) {
1.1102 + dist.set(n, a);
1.1103 + }
1.1104 + int operator[](const typename MapGraphWrapper::Node& n) const {
1.1105 + return dist[n];
1.1106 + }
1.1107 + // int get(const typename MapGraphWrapper::Node& n) const {
1.1108 + // return dist[n]; }
1.1109 + // bool get(const typename MapGraphWrapper::Edge& e) const {
1.1110 + // return (dist.get(g->tail(e))<dist.get(g->head(e))); }
1.1111 + bool operator[](const typename MapGraphWrapper::Edge& e) const {
1.1112 + return (dist[g->tail(e)]<dist[g->head(e)]);
1.1113 + }
1.1114 + };
1.1115 +
1.1116 + };
1.1117 +
1.1118 +
1.1119 +
1.1120 + template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.1121 + bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath()
1.1122 + {
1.1123 + ResGW res_graph(*g, *capacity, *flow);
1.1124 + bool _augment=false;
1.1125 +
1.1126 + //ReachedMap level(res_graph);
1.1127 + FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.1128 + BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
1.1129 + bfs.pushAndSetReached(s);
1.1130 +
1.1131 + typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
1.1132 + pred.set(s, INVALID);
1.1133 +
1.1134 + typename ResGW::template NodeMap<Num> free(res_graph);
1.1135 +
1.1136 + //searching for augmenting path
1.1137 + while ( !bfs.finished() ) {
1.1138 + ResGWOutEdgeIt e=bfs;
1.1139 + if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
1.1140 + Node v=res_graph.tail(e);
1.1141 + Node w=res_graph.head(e);
1.1142 + pred.set(w, e);
1.1143 + if (res_graph.valid(pred[v])) {
1.1144 + free.set(w, std::min(free[v], res_graph.resCap(e)));
1.1145 + } else {
1.1146 + free.set(w, res_graph.resCap(e));
1.1147 + }
1.1148 + if (res_graph.head(e)==t) { _augment=true; break; }
1.1149 + }
1.1150 +
1.1151 + ++bfs;
1.1152 + } //end of searching augmenting path
1.1153 +
1.1154 + if (_augment) {
1.1155 + Node n=t;
1.1156 + Num augment_value=free[t];
1.1157 + while (res_graph.valid(pred[n])) {
1.1158 + ResGWEdge e=pred[n];
1.1159 + res_graph.augment(e, augment_value);
1.1160 + n=res_graph.tail(e);
1.1161 + }
1.1162 + }
1.1163 +
1.1164 + status=AFTER_AUGMENTING;
1.1165 + return _augment;
1.1166 + }
1.1167 +
1.1168 + template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.1169 + bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnShortestPath2()
1.1170 + {
1.1171 + ResGW res_graph(*g, *capacity, *flow);
1.1172 + bool _augment=false;
1.1173 +
1.1174 + if (status!=AFTER_FAST_AUGMENTING) {
1.1175 + FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.1176 + number_of_augmentations=1;
1.1177 + } else {
1.1178 + ++number_of_augmentations;
1.1179 + }
1.1180 + TrickyReachedMap<ReachedMap>
1.1181 + tricky_reached_map(level, number_of_augmentations);
1.1182 + //ReachedMap level(res_graph);
1.1183 +// FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.1184 + BfsIterator<ResGW, TrickyReachedMap<ReachedMap> >
1.1185 + bfs(res_graph, tricky_reached_map);
1.1186 + bfs.pushAndSetReached(s);
1.1187 +
1.1188 + typename ResGW::template NodeMap<ResGWEdge> pred(res_graph);
1.1189 + pred.set(s, INVALID);
1.1190 +
1.1191 + typename ResGW::template NodeMap<Num> free(res_graph);
1.1192 +
1.1193 + //searching for augmenting path
1.1194 + while ( !bfs.finished() ) {
1.1195 + ResGWOutEdgeIt e=bfs;
1.1196 + if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
1.1197 + Node v=res_graph.tail(e);
1.1198 + Node w=res_graph.head(e);
1.1199 + pred.set(w, e);
1.1200 + if (res_graph.valid(pred[v])) {
1.1201 + free.set(w, std::min(free[v], res_graph.resCap(e)));
1.1202 + } else {
1.1203 + free.set(w, res_graph.resCap(e));
1.1204 + }
1.1205 + if (res_graph.head(e)==t) { _augment=true; break; }
1.1206 + }
1.1207 +
1.1208 + ++bfs;
1.1209 + } //end of searching augmenting path
1.1210 +
1.1211 + if (_augment) {
1.1212 + Node n=t;
1.1213 + Num augment_value=free[t];
1.1214 + while (res_graph.valid(pred[n])) {
1.1215 + ResGWEdge e=pred[n];
1.1216 + res_graph.augment(e, augment_value);
1.1217 + n=res_graph.tail(e);
1.1218 + }
1.1219 + }
1.1220 +
1.1221 + status=AFTER_FAST_AUGMENTING;
1.1222 + return _augment;
1.1223 + }
1.1224 +
1.1225 +
1.1226 + template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.1227 + template<typename MutableGraph>
1.1228 + bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow()
1.1229 + {
1.1230 + typedef MutableGraph MG;
1.1231 + bool _augment=false;
1.1232 +
1.1233 + ResGW res_graph(*g, *capacity, *flow);
1.1234 +
1.1235 + //bfs for distances on the residual graph
1.1236 + //ReachedMap level(res_graph);
1.1237 + FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.1238 + BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
1.1239 + bfs.pushAndSetReached(s);
1.1240 + typename ResGW::template NodeMap<int>
1.1241 + dist(res_graph); //filled up with 0's
1.1242 +
1.1243 + //F will contain the physical copy of the residual graph
1.1244 + //with the set of edges which are on shortest paths
1.1245 + MG F;
1.1246 + typename ResGW::template NodeMap<typename MG::Node>
1.1247 + res_graph_to_F(res_graph);
1.1248 + {
1.1249 + typename ResGW::NodeIt n;
1.1250 + for(res_graph.first(n); res_graph.valid(n); res_graph.next(n)) {
1.1251 + res_graph_to_F.set(n, F.addNode());
1.1252 + }
1.1253 + }
1.1254 +
1.1255 + typename MG::Node sF=res_graph_to_F[s];
1.1256 + typename MG::Node tF=res_graph_to_F[t];
1.1257 + typename MG::template EdgeMap<ResGWEdge> original_edge(F);
1.1258 + typename MG::template EdgeMap<Num> residual_capacity(F);
1.1259 +
1.1260 + while ( !bfs.finished() ) {
1.1261 + ResGWOutEdgeIt e=bfs;
1.1262 + if (res_graph.valid(e)) {
1.1263 + if (bfs.isBNodeNewlyReached()) {
1.1264 + dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
1.1265 + typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)],
1.1266 + res_graph_to_F[res_graph.head(e)]);
1.1267 + original_edge.update();
1.1268 + original_edge.set(f, e);
1.1269 + residual_capacity.update();
1.1270 + residual_capacity.set(f, res_graph.resCap(e));
1.1271 + } else {
1.1272 + if (dist[res_graph.head(e)]==(dist[res_graph.tail(e)]+1)) {
1.1273 + typename MG::Edge f=F.addEdge(res_graph_to_F[res_graph.tail(e)],
1.1274 + res_graph_to_F[res_graph.head(e)]);
1.1275 + original_edge.update();
1.1276 + original_edge.set(f, e);
1.1277 + residual_capacity.update();
1.1278 + residual_capacity.set(f, res_graph.resCap(e));
1.1279 + }
1.1280 + }
1.1281 + }
1.1282 + ++bfs;
1.1283 + } //computing distances from s in the residual graph
1.1284 +
1.1285 + bool __augment=true;
1.1286 +
1.1287 + while (__augment) {
1.1288 + __augment=false;
1.1289 + //computing blocking flow with dfs
1.1290 + DfsIterator< MG, typename MG::template NodeMap<bool> > dfs(F);
1.1291 + typename MG::template NodeMap<typename MG::Edge> pred(F);
1.1292 + pred.set(sF, INVALID);
1.1293 + //invalid iterators for sources
1.1294 +
1.1295 + typename MG::template NodeMap<Num> free(F);
1.1296 +
1.1297 + dfs.pushAndSetReached(sF);
1.1298 + while (!dfs.finished()) {
1.1299 + ++dfs;
1.1300 + if (F.valid(/*typename MG::OutEdgeIt*/(dfs))) {
1.1301 + if (dfs.isBNodeNewlyReached()) {
1.1302 + typename MG::Node v=F.aNode(dfs);
1.1303 + typename MG::Node w=F.bNode(dfs);
1.1304 + pred.set(w, dfs);
1.1305 + if (F.valid(pred[v])) {
1.1306 + free.set(w, std::min(free[v], residual_capacity[dfs]));
1.1307 + } else {
1.1308 + free.set(w, residual_capacity[dfs]);
1.1309 + }
1.1310 + if (w==tF) {
1.1311 + __augment=true;
1.1312 + _augment=true;
1.1313 + break;
1.1314 + }
1.1315 +
1.1316 + } else {
1.1317 + F.erase(/*typename MG::OutEdgeIt*/(dfs));
1.1318 + }
1.1319 + }
1.1320 + }
1.1321 +
1.1322 + if (__augment) {
1.1323 + typename MG::Node n=tF;
1.1324 + Num augment_value=free[tF];
1.1325 + while (F.valid(pred[n])) {
1.1326 + typename MG::Edge e=pred[n];
1.1327 + res_graph.augment(original_edge[e], augment_value);
1.1328 + n=F.tail(e);
1.1329 + if (residual_capacity[e]==augment_value)
1.1330 + F.erase(e);
1.1331 + else
1.1332 + residual_capacity.set(e, residual_capacity[e]-augment_value);
1.1333 + }
1.1334 + }
1.1335 +
1.1336 + }
1.1337 +
1.1338 + status=AFTER_AUGMENTING;
1.1339 + return _augment;
1.1340 + }
1.1341 +
1.1342 +
1.1343 +
1.1344 +
1.1345 + template <typename Graph, typename Num, typename CapMap, typename FlowMap>
1.1346 + bool AugmentingFlow<Graph, Num, CapMap, FlowMap>::augmentOnBlockingFlow2()
1.1347 + {
1.1348 + bool _augment=false;
1.1349 +
1.1350 + ResGW res_graph(*g, *capacity, *flow);
1.1351 +
1.1352 + //ReachedMap level(res_graph);
1.1353 + FOR_EACH_LOC(typename Graph::NodeIt, e, *g) level.set(e, 0);
1.1354 + BfsIterator<ResGW, ReachedMap> bfs(res_graph, level);
1.1355 +
1.1356 + bfs.pushAndSetReached(s);
1.1357 + DistanceMap<ResGW> dist(res_graph);
1.1358 + while ( !bfs.finished() ) {
1.1359 + ResGWOutEdgeIt e=bfs;
1.1360 + if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) {
1.1361 + dist.set(res_graph.head(e), dist[res_graph.tail(e)]+1);
1.1362 + }
1.1363 + ++bfs;
1.1364 + } //computing distances from s in the residual graph
1.1365 +
1.1366 + //Subgraph containing the edges on some shortest paths
1.1367 + ConstMap<typename ResGW::Node, bool> true_map(true);
1.1368 + typedef SubGraphWrapper<ResGW, ConstMap<typename ResGW::Node, bool>,
1.1369 + DistanceMap<ResGW> > FilterResGW;
1.1370 + FilterResGW filter_res_graph(res_graph, true_map, dist);
1.1371 +
1.1372 + //Subgraph, which is able to delete edges which are already
1.1373 + //met by the dfs
1.1374 + typename FilterResGW::template NodeMap<typename FilterResGW::OutEdgeIt>
1.1375 + first_out_edges(filter_res_graph);
1.1376 + typename FilterResGW::NodeIt v;
1.1377 + for(filter_res_graph.first(v); filter_res_graph.valid(v);
1.1378 + filter_res_graph.next(v))
1.1379 + {
1.1380 + typename FilterResGW::OutEdgeIt e;
1.1381 + filter_res_graph.first(e, v);
1.1382 + first_out_edges.set(v, e);
1.1383 + }
1.1384 + typedef ErasingFirstGraphWrapper<FilterResGW, typename FilterResGW::
1.1385 + template NodeMap<typename FilterResGW::OutEdgeIt> > ErasingResGW;
1.1386 + ErasingResGW erasing_res_graph(filter_res_graph, first_out_edges);
1.1387 +
1.1388 + bool __augment=true;
1.1389 +
1.1390 + while (__augment) {
1.1391 +
1.1392 + __augment=false;
1.1393 + //computing blocking flow with dfs
1.1394 + DfsIterator< ErasingResGW,
1.1395 + typename ErasingResGW::template NodeMap<bool> >
1.1396 + dfs(erasing_res_graph);
1.1397 + typename ErasingResGW::
1.1398 + template NodeMap<typename ErasingResGW::OutEdgeIt>
1.1399 + pred(erasing_res_graph);
1.1400 + pred.set(s, INVALID);
1.1401 + //invalid iterators for sources
1.1402 +
1.1403 + typename ErasingResGW::template NodeMap<Num>
1.1404 + free1(erasing_res_graph);
1.1405 +
1.1406 + dfs.pushAndSetReached
1.1407 + ///\bug hugo 0.2
1.1408 + (typename ErasingResGW::Node
1.1409 + (typename FilterResGW::Node
1.1410 + (typename ResGW::Node(s)
1.1411 + )
1.1412 + )
1.1413 + );
1.1414 + while (!dfs.finished()) {
1.1415 + ++dfs;
1.1416 + if (erasing_res_graph.valid(typename ErasingResGW::OutEdgeIt(dfs)))
1.1417 + {
1.1418 + if (dfs.isBNodeNewlyReached()) {
1.1419 +
1.1420 + typename ErasingResGW::Node v=erasing_res_graph.aNode(dfs);
1.1421 + typename ErasingResGW::Node w=erasing_res_graph.bNode(dfs);
1.1422 +
1.1423 + pred.set(w, /*typename ErasingResGW::OutEdgeIt*/(dfs));
1.1424 + if (erasing_res_graph.valid(pred[v])) {
1.1425 + free1.set
1.1426 + (w, std::min(free1[v], res_graph.resCap
1.1427 + (typename ErasingResGW::OutEdgeIt(dfs))));
1.1428 + } else {
1.1429 + free1.set
1.1430 + (w, res_graph.resCap
1.1431 + (typename ErasingResGW::OutEdgeIt(dfs)));
1.1432 + }
1.1433 +
1.1434 + if (w==t) {
1.1435 + __augment=true;
1.1436 + _augment=true;
1.1437 + break;
1.1438 + }
1.1439 + } else {
1.1440 + erasing_res_graph.erase(dfs);
1.1441 + }
1.1442 + }
1.1443 + }
1.1444 +
1.1445 + if (__augment) {
1.1446 + typename ErasingResGW::Node
1.1447 + n=typename FilterResGW::Node(typename ResGW::Node(t));
1.1448 + // typename ResGW::NodeMap<Num> a(res_graph);
1.1449 + // typename ResGW::Node b;
1.1450 + // Num j=a[b];
1.1451 + // typename FilterResGW::NodeMap<Num> a1(filter_res_graph);
1.1452 + // typename FilterResGW::Node b1;
1.1453 + // Num j1=a1[b1];
1.1454 + // typename ErasingResGW::NodeMap<Num> a2(erasing_res_graph);
1.1455 + // typename ErasingResGW::Node b2;
1.1456 + // Num j2=a2[b2];
1.1457 + Num augment_value=free1[n];
1.1458 + while (erasing_res_graph.valid(pred[n])) {
1.1459 + typename ErasingResGW::OutEdgeIt e=pred[n];
1.1460 + res_graph.augment(e, augment_value);
1.1461 + n=erasing_res_graph.tail(e);
1.1462 + if (res_graph.resCap(e)==0)
1.1463 + erasing_res_graph.erase(e);
1.1464 + }
1.1465 + }
1.1466 +
1.1467 + } //while (__augment)
1.1468 +
1.1469 + status=AFTER_AUGMENTING;
1.1470 + return _augment;
1.1471 + }
1.1472 +
1.1473 +
1.1474 +} //namespace hugo
1.1475 +
1.1476 +#endif //HUGO_AUGMENTING_FLOW_H
1.1477 +
1.1478 +
1.1479 +
1.1480 +