1.1 --- a/lemon/Makefile.am Mon Dec 01 14:18:40 2008 +0000
1.2 +++ b/lemon/Makefile.am Mon Dec 01 23:12:16 2008 +0100
1.3 @@ -36,6 +36,7 @@
1.4 lemon/grid_graph.h \
1.5 lemon/hypercube_graph.h \
1.6 lemon/kruskal.h \
1.7 + lemon/hao_orlin.h \
1.8 lemon/lgf_reader.h \
1.9 lemon/lgf_writer.h \
1.10 lemon/list_graph.h \
2.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
2.2 +++ b/lemon/hao_orlin.h Mon Dec 01 23:12:16 2008 +0100
2.3 @@ -0,0 +1,985 @@
2.4 +/* -*- mode: C++; indent-tabs-mode: nil; -*-
2.5 + *
2.6 + * This file is a part of LEMON, a generic C++ optimization library.
2.7 + *
2.8 + * Copyright (C) 2003-2008
2.9 + * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
2.10 + * (Egervary Research Group on Combinatorial Optimization, EGRES).
2.11 + *
2.12 + * Permission to use, modify and distribute this software is granted
2.13 + * provided that this copyright notice appears in all copies. For
2.14 + * precise terms see the accompanying LICENSE file.
2.15 + *
2.16 + * This software is provided "AS IS" with no warranty of any kind,
2.17 + * express or implied, and with no claim as to its suitability for any
2.18 + * purpose.
2.19 + *
2.20 + */
2.21 +
2.22 +#ifndef LEMON_HAO_ORLIN_H
2.23 +#define LEMON_HAO_ORLIN_H
2.24 +
2.25 +#include <vector>
2.26 +#include <list>
2.27 +#include <limits>
2.28 +
2.29 +#include <lemon/maps.h>
2.30 +#include <lemon/core.h>
2.31 +#include <lemon/tolerance.h>
2.32 +
2.33 +/// \file
2.34 +/// \ingroup min_cut
2.35 +/// \brief Implementation of the Hao-Orlin algorithm.
2.36 +///
2.37 +/// Implementation of the Hao-Orlin algorithm class for testing network
2.38 +/// reliability.
2.39 +
2.40 +namespace lemon {
2.41 +
2.42 + /// \ingroup min_cut
2.43 + ///
2.44 + /// \brief %Hao-Orlin algorithm to find a minimum cut in directed graphs.
2.45 + ///
2.46 + /// Hao-Orlin calculates a minimum cut in a directed graph
2.47 + /// \f$D=(V,A)\f$. It takes a fixed node \f$ source \in V \f$ and
2.48 + /// consists of two phases: in the first phase it determines a
2.49 + /// minimum cut with \f$ source \f$ on the source-side (i.e. a set
2.50 + /// \f$ X\subsetneq V \f$ with \f$ source \in X \f$ and minimal
2.51 + /// out-degree) and in the second phase it determines a minimum cut
2.52 + /// with \f$ source \f$ on the sink-side (i.e. a set
2.53 + /// \f$ X\subsetneq V \f$ with \f$ source \notin X \f$ and minimal
2.54 + /// out-degree). Obviously, the smaller of these two cuts will be a
2.55 + /// minimum cut of \f$ D \f$. The algorithm is a modified
2.56 + /// push-relabel preflow algorithm and our implementation calculates
2.57 + /// the minimum cut in \f$ O(n^2\sqrt{m}) \f$ time (we use the
2.58 + /// highest-label rule), or in \f$O(nm)\f$ for unit capacities. The
2.59 + /// purpose of such algorithm is testing network reliability. For an
2.60 + /// undirected graph you can run just the first phase of the
2.61 + /// algorithm or you can use the algorithm of Nagamochi and Ibaraki
2.62 + /// which solves the undirected problem in
2.63 + /// \f$ O(nm + n^2 \log(n)) \f$ time: it is implemented in the
2.64 + /// NagamochiIbaraki algorithm class.
2.65 + ///
2.66 + /// \param _Digraph is the graph type of the algorithm.
2.67 + /// \param _CapacityMap is an edge map of capacities which should
2.68 + /// be any numreric type. The default type is _Digraph::ArcMap<int>.
2.69 + /// \param _Tolerance is the handler of the inexact computation. The
2.70 + /// default type for this is Tolerance<CapacityMap::Value>.
2.71 +#ifdef DOXYGEN
2.72 + template <typename _Digraph, typename _CapacityMap, typename _Tolerance>
2.73 +#else
2.74 + template <typename _Digraph,
2.75 + typename _CapacityMap = typename _Digraph::template ArcMap<int>,
2.76 + typename _Tolerance = Tolerance<typename _CapacityMap::Value> >
2.77 +#endif
2.78 + class HaoOrlin {
2.79 + private:
2.80 +
2.81 + typedef _Digraph Digraph;
2.82 + typedef _CapacityMap CapacityMap;
2.83 + typedef _Tolerance Tolerance;
2.84 +
2.85 + typedef typename CapacityMap::Value Value;
2.86 +
2.87 + TEMPLATE_GRAPH_TYPEDEFS(Digraph);
2.88 +
2.89 + const Digraph& _graph;
2.90 + const CapacityMap* _capacity;
2.91 +
2.92 + typedef typename Digraph::template ArcMap<Value> FlowMap;
2.93 + FlowMap* _flow;
2.94 +
2.95 + Node _source;
2.96 +
2.97 + int _node_num;
2.98 +
2.99 + // Bucketing structure
2.100 + std::vector<Node> _first, _last;
2.101 + typename Digraph::template NodeMap<Node>* _next;
2.102 + typename Digraph::template NodeMap<Node>* _prev;
2.103 + typename Digraph::template NodeMap<bool>* _active;
2.104 + typename Digraph::template NodeMap<int>* _bucket;
2.105 +
2.106 + std::vector<bool> _dormant;
2.107 +
2.108 + std::list<std::list<int> > _sets;
2.109 + std::list<int>::iterator _highest;
2.110 +
2.111 + typedef typename Digraph::template NodeMap<Value> ExcessMap;
2.112 + ExcessMap* _excess;
2.113 +
2.114 + typedef typename Digraph::template NodeMap<bool> SourceSetMap;
2.115 + SourceSetMap* _source_set;
2.116 +
2.117 + Value _min_cut;
2.118 +
2.119 + typedef typename Digraph::template NodeMap<bool> MinCutMap;
2.120 + MinCutMap* _min_cut_map;
2.121 +
2.122 + Tolerance _tolerance;
2.123 +
2.124 + public:
2.125 +
2.126 + /// \brief Constructor
2.127 + ///
2.128 + /// Constructor of the algorithm class.
2.129 + HaoOrlin(const Digraph& graph, const CapacityMap& capacity,
2.130 + const Tolerance& tolerance = Tolerance()) :
2.131 + _graph(graph), _capacity(&capacity), _flow(0), _source(),
2.132 + _node_num(), _first(), _last(), _next(0), _prev(0),
2.133 + _active(0), _bucket(0), _dormant(), _sets(), _highest(),
2.134 + _excess(0), _source_set(0), _min_cut(), _min_cut_map(0),
2.135 + _tolerance(tolerance) {}
2.136 +
2.137 + ~HaoOrlin() {
2.138 + if (_min_cut_map) {
2.139 + delete _min_cut_map;
2.140 + }
2.141 + if (_source_set) {
2.142 + delete _source_set;
2.143 + }
2.144 + if (_excess) {
2.145 + delete _excess;
2.146 + }
2.147 + if (_next) {
2.148 + delete _next;
2.149 + }
2.150 + if (_prev) {
2.151 + delete _prev;
2.152 + }
2.153 + if (_active) {
2.154 + delete _active;
2.155 + }
2.156 + if (_bucket) {
2.157 + delete _bucket;
2.158 + }
2.159 + if (_flow) {
2.160 + delete _flow;
2.161 + }
2.162 + }
2.163 +
2.164 + private:
2.165 +
2.166 + void activate(const Node& i) {
2.167 + _active->set(i, true);
2.168 +
2.169 + int bucket = (*_bucket)[i];
2.170 +
2.171 + if ((*_prev)[i] == INVALID || (*_active)[(*_prev)[i]]) return;
2.172 + //unlace
2.173 + _next->set((*_prev)[i], (*_next)[i]);
2.174 + if ((*_next)[i] != INVALID) {
2.175 + _prev->set((*_next)[i], (*_prev)[i]);
2.176 + } else {
2.177 + _last[bucket] = (*_prev)[i];
2.178 + }
2.179 + //lace
2.180 + _next->set(i, _first[bucket]);
2.181 + _prev->set(_first[bucket], i);
2.182 + _prev->set(i, INVALID);
2.183 + _first[bucket] = i;
2.184 + }
2.185 +
2.186 + void deactivate(const Node& i) {
2.187 + _active->set(i, false);
2.188 + int bucket = (*_bucket)[i];
2.189 +
2.190 + if ((*_next)[i] == INVALID || !(*_active)[(*_next)[i]]) return;
2.191 +
2.192 + //unlace
2.193 + _prev->set((*_next)[i], (*_prev)[i]);
2.194 + if ((*_prev)[i] != INVALID) {
2.195 + _next->set((*_prev)[i], (*_next)[i]);
2.196 + } else {
2.197 + _first[bucket] = (*_next)[i];
2.198 + }
2.199 + //lace
2.200 + _prev->set(i, _last[bucket]);
2.201 + _next->set(_last[bucket], i);
2.202 + _next->set(i, INVALID);
2.203 + _last[bucket] = i;
2.204 + }
2.205 +
2.206 + void addItem(const Node& i, int bucket) {
2.207 + (*_bucket)[i] = bucket;
2.208 + if (_last[bucket] != INVALID) {
2.209 + _prev->set(i, _last[bucket]);
2.210 + _next->set(_last[bucket], i);
2.211 + _next->set(i, INVALID);
2.212 + _last[bucket] = i;
2.213 + } else {
2.214 + _prev->set(i, INVALID);
2.215 + _first[bucket] = i;
2.216 + _next->set(i, INVALID);
2.217 + _last[bucket] = i;
2.218 + }
2.219 + }
2.220 +
2.221 + void findMinCutOut() {
2.222 +
2.223 + for (NodeIt n(_graph); n != INVALID; ++n) {
2.224 + _excess->set(n, 0);
2.225 + }
2.226 +
2.227 + for (ArcIt a(_graph); a != INVALID; ++a) {
2.228 + _flow->set(a, 0);
2.229 + }
2.230 +
2.231 + int bucket_num = 1;
2.232 +
2.233 + {
2.234 + typename Digraph::template NodeMap<bool> reached(_graph, false);
2.235 +
2.236 + reached.set(_source, true);
2.237 +
2.238 + bool first_set = true;
2.239 +
2.240 + for (NodeIt t(_graph); t != INVALID; ++t) {
2.241 + if (reached[t]) continue;
2.242 + _sets.push_front(std::list<int>());
2.243 + _sets.front().push_front(bucket_num);
2.244 + _dormant[bucket_num] = !first_set;
2.245 +
2.246 + _bucket->set(t, bucket_num);
2.247 + _first[bucket_num] = _last[bucket_num] = t;
2.248 + _next->set(t, INVALID);
2.249 + _prev->set(t, INVALID);
2.250 +
2.251 + ++bucket_num;
2.252 +
2.253 + std::vector<Node> queue;
2.254 + queue.push_back(t);
2.255 + reached.set(t, true);
2.256 +
2.257 + while (!queue.empty()) {
2.258 + _sets.front().push_front(bucket_num);
2.259 + _dormant[bucket_num] = !first_set;
2.260 + _first[bucket_num] = _last[bucket_num] = INVALID;
2.261 +
2.262 + std::vector<Node> nqueue;
2.263 + for (int i = 0; i < int(queue.size()); ++i) {
2.264 + Node n = queue[i];
2.265 + for (InArcIt a(_graph, n); a != INVALID; ++a) {
2.266 + Node u = _graph.source(a);
2.267 + if (!reached[u] && _tolerance.positive((*_capacity)[a])) {
2.268 + reached.set(u, true);
2.269 + addItem(u, bucket_num);
2.270 + nqueue.push_back(u);
2.271 + }
2.272 + }
2.273 + }
2.274 + queue.swap(nqueue);
2.275 + ++bucket_num;
2.276 + }
2.277 + _sets.front().pop_front();
2.278 + --bucket_num;
2.279 + first_set = false;
2.280 + }
2.281 +
2.282 + _bucket->set(_source, 0);
2.283 + _dormant[0] = true;
2.284 + }
2.285 + _source_set->set(_source, true);
2.286 +
2.287 + Node target = _last[_sets.back().back()];
2.288 + {
2.289 + for (OutArcIt a(_graph, _source); a != INVALID; ++a) {
2.290 + if (_tolerance.positive((*_capacity)[a])) {
2.291 + Node u = _graph.target(a);
2.292 + _flow->set(a, (*_capacity)[a]);
2.293 + _excess->set(u, (*_excess)[u] + (*_capacity)[a]);
2.294 + if (!(*_active)[u] && u != _source) {
2.295 + activate(u);
2.296 + }
2.297 + }
2.298 + }
2.299 +
2.300 + if ((*_active)[target]) {
2.301 + deactivate(target);
2.302 + }
2.303 +
2.304 + _highest = _sets.back().begin();
2.305 + while (_highest != _sets.back().end() &&
2.306 + !(*_active)[_first[*_highest]]) {
2.307 + ++_highest;
2.308 + }
2.309 + }
2.310 +
2.311 + while (true) {
2.312 + while (_highest != _sets.back().end()) {
2.313 + Node n = _first[*_highest];
2.314 + Value excess = (*_excess)[n];
2.315 + int next_bucket = _node_num;
2.316 +
2.317 + int under_bucket;
2.318 + if (++std::list<int>::iterator(_highest) == _sets.back().end()) {
2.319 + under_bucket = -1;
2.320 + } else {
2.321 + under_bucket = *(++std::list<int>::iterator(_highest));
2.322 + }
2.323 +
2.324 + for (OutArcIt a(_graph, n); a != INVALID; ++a) {
2.325 + Node v = _graph.target(a);
2.326 + if (_dormant[(*_bucket)[v]]) continue;
2.327 + Value rem = (*_capacity)[a] - (*_flow)[a];
2.328 + if (!_tolerance.positive(rem)) continue;
2.329 + if ((*_bucket)[v] == under_bucket) {
2.330 + if (!(*_active)[v] && v != target) {
2.331 + activate(v);
2.332 + }
2.333 + if (!_tolerance.less(rem, excess)) {
2.334 + _flow->set(a, (*_flow)[a] + excess);
2.335 + _excess->set(v, (*_excess)[v] + excess);
2.336 + excess = 0;
2.337 + goto no_more_push;
2.338 + } else {
2.339 + excess -= rem;
2.340 + _excess->set(v, (*_excess)[v] + rem);
2.341 + _flow->set(a, (*_capacity)[a]);
2.342 + }
2.343 + } else if (next_bucket > (*_bucket)[v]) {
2.344 + next_bucket = (*_bucket)[v];
2.345 + }
2.346 + }
2.347 +
2.348 + for (InArcIt a(_graph, n); a != INVALID; ++a) {
2.349 + Node v = _graph.source(a);
2.350 + if (_dormant[(*_bucket)[v]]) continue;
2.351 + Value rem = (*_flow)[a];
2.352 + if (!_tolerance.positive(rem)) continue;
2.353 + if ((*_bucket)[v] == under_bucket) {
2.354 + if (!(*_active)[v] && v != target) {
2.355 + activate(v);
2.356 + }
2.357 + if (!_tolerance.less(rem, excess)) {
2.358 + _flow->set(a, (*_flow)[a] - excess);
2.359 + _excess->set(v, (*_excess)[v] + excess);
2.360 + excess = 0;
2.361 + goto no_more_push;
2.362 + } else {
2.363 + excess -= rem;
2.364 + _excess->set(v, (*_excess)[v] + rem);
2.365 + _flow->set(a, 0);
2.366 + }
2.367 + } else if (next_bucket > (*_bucket)[v]) {
2.368 + next_bucket = (*_bucket)[v];
2.369 + }
2.370 + }
2.371 +
2.372 + no_more_push:
2.373 +
2.374 + _excess->set(n, excess);
2.375 +
2.376 + if (excess != 0) {
2.377 + if ((*_next)[n] == INVALID) {
2.378 + typename std::list<std::list<int> >::iterator new_set =
2.379 + _sets.insert(--_sets.end(), std::list<int>());
2.380 + new_set->splice(new_set->end(), _sets.back(),
2.381 + _sets.back().begin(), ++_highest);
2.382 + for (std::list<int>::iterator it = new_set->begin();
2.383 + it != new_set->end(); ++it) {
2.384 + _dormant[*it] = true;
2.385 + }
2.386 + while (_highest != _sets.back().end() &&
2.387 + !(*_active)[_first[*_highest]]) {
2.388 + ++_highest;
2.389 + }
2.390 + } else if (next_bucket == _node_num) {
2.391 + _first[(*_bucket)[n]] = (*_next)[n];
2.392 + _prev->set((*_next)[n], INVALID);
2.393 +
2.394 + std::list<std::list<int> >::iterator new_set =
2.395 + _sets.insert(--_sets.end(), std::list<int>());
2.396 +
2.397 + new_set->push_front(bucket_num);
2.398 + _bucket->set(n, bucket_num);
2.399 + _first[bucket_num] = _last[bucket_num] = n;
2.400 + _next->set(n, INVALID);
2.401 + _prev->set(n, INVALID);
2.402 + _dormant[bucket_num] = true;
2.403 + ++bucket_num;
2.404 +
2.405 + while (_highest != _sets.back().end() &&
2.406 + !(*_active)[_first[*_highest]]) {
2.407 + ++_highest;
2.408 + }
2.409 + } else {
2.410 + _first[*_highest] = (*_next)[n];
2.411 + _prev->set((*_next)[n], INVALID);
2.412 +
2.413 + while (next_bucket != *_highest) {
2.414 + --_highest;
2.415 + }
2.416 +
2.417 + if (_highest == _sets.back().begin()) {
2.418 + _sets.back().push_front(bucket_num);
2.419 + _dormant[bucket_num] = false;
2.420 + _first[bucket_num] = _last[bucket_num] = INVALID;
2.421 + ++bucket_num;
2.422 + }
2.423 + --_highest;
2.424 +
2.425 + _bucket->set(n, *_highest);
2.426 + _next->set(n, _first[*_highest]);
2.427 + if (_first[*_highest] != INVALID) {
2.428 + _prev->set(_first[*_highest], n);
2.429 + } else {
2.430 + _last[*_highest] = n;
2.431 + }
2.432 + _first[*_highest] = n;
2.433 + }
2.434 + } else {
2.435 +
2.436 + deactivate(n);
2.437 + if (!(*_active)[_first[*_highest]]) {
2.438 + ++_highest;
2.439 + if (_highest != _sets.back().end() &&
2.440 + !(*_active)[_first[*_highest]]) {
2.441 + _highest = _sets.back().end();
2.442 + }
2.443 + }
2.444 + }
2.445 + }
2.446 +
2.447 + if ((*_excess)[target] < _min_cut) {
2.448 + _min_cut = (*_excess)[target];
2.449 + for (NodeIt i(_graph); i != INVALID; ++i) {
2.450 + _min_cut_map->set(i, true);
2.451 + }
2.452 + for (std::list<int>::iterator it = _sets.back().begin();
2.453 + it != _sets.back().end(); ++it) {
2.454 + Node n = _first[*it];
2.455 + while (n != INVALID) {
2.456 + _min_cut_map->set(n, false);
2.457 + n = (*_next)[n];
2.458 + }
2.459 + }
2.460 + }
2.461 +
2.462 + {
2.463 + Node new_target;
2.464 + if ((*_prev)[target] != INVALID || (*_next)[target] != INVALID) {
2.465 + if ((*_next)[target] == INVALID) {
2.466 + _last[(*_bucket)[target]] = (*_prev)[target];
2.467 + new_target = (*_prev)[target];
2.468 + } else {
2.469 + _prev->set((*_next)[target], (*_prev)[target]);
2.470 + new_target = (*_next)[target];
2.471 + }
2.472 + if ((*_prev)[target] == INVALID) {
2.473 + _first[(*_bucket)[target]] = (*_next)[target];
2.474 + } else {
2.475 + _next->set((*_prev)[target], (*_next)[target]);
2.476 + }
2.477 + } else {
2.478 + _sets.back().pop_back();
2.479 + if (_sets.back().empty()) {
2.480 + _sets.pop_back();
2.481 + if (_sets.empty())
2.482 + break;
2.483 + for (std::list<int>::iterator it = _sets.back().begin();
2.484 + it != _sets.back().end(); ++it) {
2.485 + _dormant[*it] = false;
2.486 + }
2.487 + }
2.488 + new_target = _last[_sets.back().back()];
2.489 + }
2.490 +
2.491 + _bucket->set(target, 0);
2.492 +
2.493 + _source_set->set(target, true);
2.494 + for (OutArcIt a(_graph, target); a != INVALID; ++a) {
2.495 + Value rem = (*_capacity)[a] - (*_flow)[a];
2.496 + if (!_tolerance.positive(rem)) continue;
2.497 + Node v = _graph.target(a);
2.498 + if (!(*_active)[v] && !(*_source_set)[v]) {
2.499 + activate(v);
2.500 + }
2.501 + _excess->set(v, (*_excess)[v] + rem);
2.502 + _flow->set(a, (*_capacity)[a]);
2.503 + }
2.504 +
2.505 + for (InArcIt a(_graph, target); a != INVALID; ++a) {
2.506 + Value rem = (*_flow)[a];
2.507 + if (!_tolerance.positive(rem)) continue;
2.508 + Node v = _graph.source(a);
2.509 + if (!(*_active)[v] && !(*_source_set)[v]) {
2.510 + activate(v);
2.511 + }
2.512 + _excess->set(v, (*_excess)[v] + rem);
2.513 + _flow->set(a, 0);
2.514 + }
2.515 +
2.516 + target = new_target;
2.517 + if ((*_active)[target]) {
2.518 + deactivate(target);
2.519 + }
2.520 +
2.521 + _highest = _sets.back().begin();
2.522 + while (_highest != _sets.back().end() &&
2.523 + !(*_active)[_first[*_highest]]) {
2.524 + ++_highest;
2.525 + }
2.526 + }
2.527 + }
2.528 + }
2.529 +
2.530 + void findMinCutIn() {
2.531 +
2.532 + for (NodeIt n(_graph); n != INVALID; ++n) {
2.533 + _excess->set(n, 0);
2.534 + }
2.535 +
2.536 + for (ArcIt a(_graph); a != INVALID; ++a) {
2.537 + _flow->set(a, 0);
2.538 + }
2.539 +
2.540 + int bucket_num = 1;
2.541 +
2.542 + {
2.543 + typename Digraph::template NodeMap<bool> reached(_graph, false);
2.544 +
2.545 + reached.set(_source, true);
2.546 +
2.547 + bool first_set = true;
2.548 +
2.549 + for (NodeIt t(_graph); t != INVALID; ++t) {
2.550 + if (reached[t]) continue;
2.551 + _sets.push_front(std::list<int>());
2.552 + _sets.front().push_front(bucket_num);
2.553 + _dormant[bucket_num] = !first_set;
2.554 +
2.555 + _bucket->set(t, bucket_num);
2.556 + _first[bucket_num] = _last[bucket_num] = t;
2.557 + _next->set(t, INVALID);
2.558 + _prev->set(t, INVALID);
2.559 +
2.560 + ++bucket_num;
2.561 +
2.562 + std::vector<Node> queue;
2.563 + queue.push_back(t);
2.564 + reached.set(t, true);
2.565 +
2.566 + while (!queue.empty()) {
2.567 + _sets.front().push_front(bucket_num);
2.568 + _dormant[bucket_num] = !first_set;
2.569 + _first[bucket_num] = _last[bucket_num] = INVALID;
2.570 +
2.571 + std::vector<Node> nqueue;
2.572 + for (int i = 0; i < int(queue.size()); ++i) {
2.573 + Node n = queue[i];
2.574 + for (OutArcIt a(_graph, n); a != INVALID; ++a) {
2.575 + Node u = _graph.target(a);
2.576 + if (!reached[u] && _tolerance.positive((*_capacity)[a])) {
2.577 + reached.set(u, true);
2.578 + addItem(u, bucket_num);
2.579 + nqueue.push_back(u);
2.580 + }
2.581 + }
2.582 + }
2.583 + queue.swap(nqueue);
2.584 + ++bucket_num;
2.585 + }
2.586 + _sets.front().pop_front();
2.587 + --bucket_num;
2.588 + first_set = false;
2.589 + }
2.590 +
2.591 + _bucket->set(_source, 0);
2.592 + _dormant[0] = true;
2.593 + }
2.594 + _source_set->set(_source, true);
2.595 +
2.596 + Node target = _last[_sets.back().back()];
2.597 + {
2.598 + for (InArcIt a(_graph, _source); a != INVALID; ++a) {
2.599 + if (_tolerance.positive((*_capacity)[a])) {
2.600 + Node u = _graph.source(a);
2.601 + _flow->set(a, (*_capacity)[a]);
2.602 + _excess->set(u, (*_excess)[u] + (*_capacity)[a]);
2.603 + if (!(*_active)[u] && u != _source) {
2.604 + activate(u);
2.605 + }
2.606 + }
2.607 + }
2.608 + if ((*_active)[target]) {
2.609 + deactivate(target);
2.610 + }
2.611 +
2.612 + _highest = _sets.back().begin();
2.613 + while (_highest != _sets.back().end() &&
2.614 + !(*_active)[_first[*_highest]]) {
2.615 + ++_highest;
2.616 + }
2.617 + }
2.618 +
2.619 +
2.620 + while (true) {
2.621 + while (_highest != _sets.back().end()) {
2.622 + Node n = _first[*_highest];
2.623 + Value excess = (*_excess)[n];
2.624 + int next_bucket = _node_num;
2.625 +
2.626 + int under_bucket;
2.627 + if (++std::list<int>::iterator(_highest) == _sets.back().end()) {
2.628 + under_bucket = -1;
2.629 + } else {
2.630 + under_bucket = *(++std::list<int>::iterator(_highest));
2.631 + }
2.632 +
2.633 + for (InArcIt a(_graph, n); a != INVALID; ++a) {
2.634 + Node v = _graph.source(a);
2.635 + if (_dormant[(*_bucket)[v]]) continue;
2.636 + Value rem = (*_capacity)[a] - (*_flow)[a];
2.637 + if (!_tolerance.positive(rem)) continue;
2.638 + if ((*_bucket)[v] == under_bucket) {
2.639 + if (!(*_active)[v] && v != target) {
2.640 + activate(v);
2.641 + }
2.642 + if (!_tolerance.less(rem, excess)) {
2.643 + _flow->set(a, (*_flow)[a] + excess);
2.644 + _excess->set(v, (*_excess)[v] + excess);
2.645 + excess = 0;
2.646 + goto no_more_push;
2.647 + } else {
2.648 + excess -= rem;
2.649 + _excess->set(v, (*_excess)[v] + rem);
2.650 + _flow->set(a, (*_capacity)[a]);
2.651 + }
2.652 + } else if (next_bucket > (*_bucket)[v]) {
2.653 + next_bucket = (*_bucket)[v];
2.654 + }
2.655 + }
2.656 +
2.657 + for (OutArcIt a(_graph, n); a != INVALID; ++a) {
2.658 + Node v = _graph.target(a);
2.659 + if (_dormant[(*_bucket)[v]]) continue;
2.660 + Value rem = (*_flow)[a];
2.661 + if (!_tolerance.positive(rem)) continue;
2.662 + if ((*_bucket)[v] == under_bucket) {
2.663 + if (!(*_active)[v] && v != target) {
2.664 + activate(v);
2.665 + }
2.666 + if (!_tolerance.less(rem, excess)) {
2.667 + _flow->set(a, (*_flow)[a] - excess);
2.668 + _excess->set(v, (*_excess)[v] + excess);
2.669 + excess = 0;
2.670 + goto no_more_push;
2.671 + } else {
2.672 + excess -= rem;
2.673 + _excess->set(v, (*_excess)[v] + rem);
2.674 + _flow->set(a, 0);
2.675 + }
2.676 + } else if (next_bucket > (*_bucket)[v]) {
2.677 + next_bucket = (*_bucket)[v];
2.678 + }
2.679 + }
2.680 +
2.681 + no_more_push:
2.682 +
2.683 + _excess->set(n, excess);
2.684 +
2.685 + if (excess != 0) {
2.686 + if ((*_next)[n] == INVALID) {
2.687 + typename std::list<std::list<int> >::iterator new_set =
2.688 + _sets.insert(--_sets.end(), std::list<int>());
2.689 + new_set->splice(new_set->end(), _sets.back(),
2.690 + _sets.back().begin(), ++_highest);
2.691 + for (std::list<int>::iterator it = new_set->begin();
2.692 + it != new_set->end(); ++it) {
2.693 + _dormant[*it] = true;
2.694 + }
2.695 + while (_highest != _sets.back().end() &&
2.696 + !(*_active)[_first[*_highest]]) {
2.697 + ++_highest;
2.698 + }
2.699 + } else if (next_bucket == _node_num) {
2.700 + _first[(*_bucket)[n]] = (*_next)[n];
2.701 + _prev->set((*_next)[n], INVALID);
2.702 +
2.703 + std::list<std::list<int> >::iterator new_set =
2.704 + _sets.insert(--_sets.end(), std::list<int>());
2.705 +
2.706 + new_set->push_front(bucket_num);
2.707 + _bucket->set(n, bucket_num);
2.708 + _first[bucket_num] = _last[bucket_num] = n;
2.709 + _next->set(n, INVALID);
2.710 + _prev->set(n, INVALID);
2.711 + _dormant[bucket_num] = true;
2.712 + ++bucket_num;
2.713 +
2.714 + while (_highest != _sets.back().end() &&
2.715 + !(*_active)[_first[*_highest]]) {
2.716 + ++_highest;
2.717 + }
2.718 + } else {
2.719 + _first[*_highest] = (*_next)[n];
2.720 + _prev->set((*_next)[n], INVALID);
2.721 +
2.722 + while (next_bucket != *_highest) {
2.723 + --_highest;
2.724 + }
2.725 + if (_highest == _sets.back().begin()) {
2.726 + _sets.back().push_front(bucket_num);
2.727 + _dormant[bucket_num] = false;
2.728 + _first[bucket_num] = _last[bucket_num] = INVALID;
2.729 + ++bucket_num;
2.730 + }
2.731 + --_highest;
2.732 +
2.733 + _bucket->set(n, *_highest);
2.734 + _next->set(n, _first[*_highest]);
2.735 + if (_first[*_highest] != INVALID) {
2.736 + _prev->set(_first[*_highest], n);
2.737 + } else {
2.738 + _last[*_highest] = n;
2.739 + }
2.740 + _first[*_highest] = n;
2.741 + }
2.742 + } else {
2.743 +
2.744 + deactivate(n);
2.745 + if (!(*_active)[_first[*_highest]]) {
2.746 + ++_highest;
2.747 + if (_highest != _sets.back().end() &&
2.748 + !(*_active)[_first[*_highest]]) {
2.749 + _highest = _sets.back().end();
2.750 + }
2.751 + }
2.752 + }
2.753 + }
2.754 +
2.755 + if ((*_excess)[target] < _min_cut) {
2.756 + _min_cut = (*_excess)[target];
2.757 + for (NodeIt i(_graph); i != INVALID; ++i) {
2.758 + _min_cut_map->set(i, false);
2.759 + }
2.760 + for (std::list<int>::iterator it = _sets.back().begin();
2.761 + it != _sets.back().end(); ++it) {
2.762 + Node n = _first[*it];
2.763 + while (n != INVALID) {
2.764 + _min_cut_map->set(n, true);
2.765 + n = (*_next)[n];
2.766 + }
2.767 + }
2.768 + }
2.769 +
2.770 + {
2.771 + Node new_target;
2.772 + if ((*_prev)[target] != INVALID || (*_next)[target] != INVALID) {
2.773 + if ((*_next)[target] == INVALID) {
2.774 + _last[(*_bucket)[target]] = (*_prev)[target];
2.775 + new_target = (*_prev)[target];
2.776 + } else {
2.777 + _prev->set((*_next)[target], (*_prev)[target]);
2.778 + new_target = (*_next)[target];
2.779 + }
2.780 + if ((*_prev)[target] == INVALID) {
2.781 + _first[(*_bucket)[target]] = (*_next)[target];
2.782 + } else {
2.783 + _next->set((*_prev)[target], (*_next)[target]);
2.784 + }
2.785 + } else {
2.786 + _sets.back().pop_back();
2.787 + if (_sets.back().empty()) {
2.788 + _sets.pop_back();
2.789 + if (_sets.empty())
2.790 + break;
2.791 + for (std::list<int>::iterator it = _sets.back().begin();
2.792 + it != _sets.back().end(); ++it) {
2.793 + _dormant[*it] = false;
2.794 + }
2.795 + }
2.796 + new_target = _last[_sets.back().back()];
2.797 + }
2.798 +
2.799 + _bucket->set(target, 0);
2.800 +
2.801 + _source_set->set(target, true);
2.802 + for (InArcIt a(_graph, target); a != INVALID; ++a) {
2.803 + Value rem = (*_capacity)[a] - (*_flow)[a];
2.804 + if (!_tolerance.positive(rem)) continue;
2.805 + Node v = _graph.source(a);
2.806 + if (!(*_active)[v] && !(*_source_set)[v]) {
2.807 + activate(v);
2.808 + }
2.809 + _excess->set(v, (*_excess)[v] + rem);
2.810 + _flow->set(a, (*_capacity)[a]);
2.811 + }
2.812 +
2.813 + for (OutArcIt a(_graph, target); a != INVALID; ++a) {
2.814 + Value rem = (*_flow)[a];
2.815 + if (!_tolerance.positive(rem)) continue;
2.816 + Node v = _graph.target(a);
2.817 + if (!(*_active)[v] && !(*_source_set)[v]) {
2.818 + activate(v);
2.819 + }
2.820 + _excess->set(v, (*_excess)[v] + rem);
2.821 + _flow->set(a, 0);
2.822 + }
2.823 +
2.824 + target = new_target;
2.825 + if ((*_active)[target]) {
2.826 + deactivate(target);
2.827 + }
2.828 +
2.829 + _highest = _sets.back().begin();
2.830 + while (_highest != _sets.back().end() &&
2.831 + !(*_active)[_first[*_highest]]) {
2.832 + ++_highest;
2.833 + }
2.834 + }
2.835 + }
2.836 + }
2.837 +
2.838 + public:
2.839 +
2.840 + /// \name Execution control
2.841 + /// The simplest way to execute the algorithm is to use
2.842 + /// one of the member functions called \c run(...).
2.843 + /// \n
2.844 + /// If you need more control on the execution,
2.845 + /// first you must call \ref init(), then the \ref calculateIn() or
2.846 + /// \ref calculateIn() functions.
2.847 +
2.848 + /// @{
2.849 +
2.850 + /// \brief Initializes the internal data structures.
2.851 + ///
2.852 + /// Initializes the internal data structures. It creates
2.853 + /// the maps, residual graph adaptors and some bucket structures
2.854 + /// for the algorithm.
2.855 + void init() {
2.856 + init(NodeIt(_graph));
2.857 + }
2.858 +
2.859 + /// \brief Initializes the internal data structures.
2.860 + ///
2.861 + /// Initializes the internal data structures. It creates
2.862 + /// the maps, residual graph adaptor and some bucket structures
2.863 + /// for the algorithm. Node \c source is used as the push-relabel
2.864 + /// algorithm's source.
2.865 + void init(const Node& source) {
2.866 + _source = source;
2.867 +
2.868 + _node_num = countNodes(_graph);
2.869 +
2.870 + _first.resize(_node_num + 1);
2.871 + _last.resize(_node_num + 1);
2.872 +
2.873 + _dormant.resize(_node_num + 1);
2.874 +
2.875 + if (!_flow) {
2.876 + _flow = new FlowMap(_graph);
2.877 + }
2.878 + if (!_next) {
2.879 + _next = new typename Digraph::template NodeMap<Node>(_graph);
2.880 + }
2.881 + if (!_prev) {
2.882 + _prev = new typename Digraph::template NodeMap<Node>(_graph);
2.883 + }
2.884 + if (!_active) {
2.885 + _active = new typename Digraph::template NodeMap<bool>(_graph);
2.886 + }
2.887 + if (!_bucket) {
2.888 + _bucket = new typename Digraph::template NodeMap<int>(_graph);
2.889 + }
2.890 + if (!_excess) {
2.891 + _excess = new ExcessMap(_graph);
2.892 + }
2.893 + if (!_source_set) {
2.894 + _source_set = new SourceSetMap(_graph);
2.895 + }
2.896 + if (!_min_cut_map) {
2.897 + _min_cut_map = new MinCutMap(_graph);
2.898 + }
2.899 +
2.900 + _min_cut = std::numeric_limits<Value>::max();
2.901 + }
2.902 +
2.903 +
2.904 + /// \brief Calculates a minimum cut with \f$ source \f$ on the
2.905 + /// source-side.
2.906 + ///
2.907 + /// Calculates a minimum cut with \f$ source \f$ on the
2.908 + /// source-side (i.e. a set \f$ X\subsetneq V \f$ with \f$ source
2.909 + /// \in X \f$ and minimal out-degree).
2.910 + void calculateOut() {
2.911 + findMinCutOut();
2.912 + }
2.913 +
2.914 + /// \brief Calculates a minimum cut with \f$ source \f$ on the
2.915 + /// target-side.
2.916 + ///
2.917 + /// Calculates a minimum cut with \f$ source \f$ on the
2.918 + /// target-side (i.e. a set \f$ X\subsetneq V \f$ with \f$ source
2.919 + /// \in X \f$ and minimal out-degree).
2.920 + void calculateIn() {
2.921 + findMinCutIn();
2.922 + }
2.923 +
2.924 +
2.925 + /// \brief Runs the algorithm.
2.926 + ///
2.927 + /// Runs the algorithm. It finds nodes \c source and \c target
2.928 + /// arbitrarily and then calls \ref init(), \ref calculateOut()
2.929 + /// and \ref calculateIn().
2.930 + void run() {
2.931 + init();
2.932 + calculateOut();
2.933 + calculateIn();
2.934 + }
2.935 +
2.936 + /// \brief Runs the algorithm.
2.937 + ///
2.938 + /// Runs the algorithm. It uses the given \c source node, finds a
2.939 + /// proper \c target and then calls the \ref init(), \ref
2.940 + /// calculateOut() and \ref calculateIn().
2.941 + void run(const Node& s) {
2.942 + init(s);
2.943 + calculateOut();
2.944 + calculateIn();
2.945 + }
2.946 +
2.947 + /// @}
2.948 +
2.949 + /// \name Query Functions
2.950 + /// The result of the %HaoOrlin algorithm
2.951 + /// can be obtained using these functions.
2.952 + /// \n
2.953 + /// Before using these functions, either \ref run(), \ref
2.954 + /// calculateOut() or \ref calculateIn() must be called.
2.955 +
2.956 + /// @{
2.957 +
2.958 + /// \brief Returns the value of the minimum value cut.
2.959 + ///
2.960 + /// Returns the value of the minimum value cut.
2.961 + Value minCutValue() const {
2.962 + return _min_cut;
2.963 + }
2.964 +
2.965 +
2.966 + /// \brief Returns a minimum cut.
2.967 + ///
2.968 + /// Sets \c nodeMap to the characteristic vector of a minimum
2.969 + /// value cut: it will give a nonempty set \f$ X\subsetneq V \f$
2.970 + /// with minimal out-degree (i.e. \c nodeMap will be true exactly
2.971 + /// for the nodes of \f$ X \f$). \pre nodeMap should be a
2.972 + /// bool-valued node-map.
2.973 + template <typename NodeMap>
2.974 + Value minCutMap(NodeMap& nodeMap) const {
2.975 + for (NodeIt it(_graph); it != INVALID; ++it) {
2.976 + nodeMap.set(it, (*_min_cut_map)[it]);
2.977 + }
2.978 + return _min_cut;
2.979 + }
2.980 +
2.981 + /// @}
2.982 +
2.983 + }; //class HaoOrlin
2.984 +
2.985 +
2.986 +} //namespace lemon
2.987 +
2.988 +#endif //LEMON_HAO_ORLIN_H