... | ... |
@@ -224,33 +224,32 @@ |
224 | 224 |
const Value& operator[](const Key& key) const { |
225 | 225 |
return _v[StaticDigraph::id(key)]; |
226 | 226 |
} |
227 | 227 |
|
228 | 228 |
Value& operator[](const Key& key) { |
229 | 229 |
return _v[StaticDigraph::id(key)]; |
230 | 230 |
} |
231 | 231 |
|
232 | 232 |
void set(const Key& key, const Value& val) { |
233 | 233 |
_v[StaticDigraph::id(key)] = val; |
234 | 234 |
} |
235 | 235 |
|
236 | 236 |
private: |
237 | 237 |
std::vector<Value>& _v; |
238 | 238 |
}; |
239 | 239 |
|
240 |
typedef StaticVectorMap<StaticDigraph::Node, LargeCost> LargeCostNodeMap; |
|
241 | 240 |
typedef StaticVectorMap<StaticDigraph::Arc, LargeCost> LargeCostArcMap; |
242 | 241 |
|
243 | 242 |
private: |
244 | 243 |
|
245 | 244 |
// Data related to the underlying digraph |
246 | 245 |
const GR &_graph; |
247 | 246 |
int _node_num; |
248 | 247 |
int _arc_num; |
249 | 248 |
int _res_node_num; |
250 | 249 |
int _res_arc_num; |
251 | 250 |
int _root; |
252 | 251 |
|
253 | 252 |
// Parameters of the problem |
254 | 253 |
bool _have_lower; |
255 | 254 |
Value _sum_supply; |
256 | 255 |
int _sup_node_num; |
... | ... |
@@ -275,40 +274,32 @@ |
275 | 274 |
LargeCostVector _cost; |
276 | 275 |
LargeCostVector _pi; |
277 | 276 |
ValueVector _excess; |
278 | 277 |
IntVector _next_out; |
279 | 278 |
std::deque<int> _active_nodes; |
280 | 279 |
|
281 | 280 |
// Data for scaling |
282 | 281 |
LargeCost _epsilon; |
283 | 282 |
int _alpha; |
284 | 283 |
|
285 | 284 |
IntVector _buckets; |
286 | 285 |
IntVector _bucket_next; |
287 | 286 |
IntVector _bucket_prev; |
288 | 287 |
IntVector _rank; |
289 | 288 |
int _max_rank; |
290 | 289 |
|
291 |
// Data for a StaticDigraph structure |
|
292 |
typedef std::pair<int, int> IntPair; |
|
293 |
StaticDigraph _sgr; |
|
294 |
std::vector<IntPair> _arc_vec; |
|
295 |
std::vector<LargeCost> _cost_vec; |
|
296 |
LargeCostArcMap _cost_map; |
|
297 |
LargeCostNodeMap _pi_map; |
|
298 |
|
|
299 | 290 |
public: |
300 | 291 |
|
301 | 292 |
/// \brief Constant for infinite upper bounds (capacities). |
302 | 293 |
/// |
303 | 294 |
/// Constant for infinite upper bounds (capacities). |
304 | 295 |
/// It is \c std::numeric_limits<Value>::infinity() if available, |
305 | 296 |
/// \c std::numeric_limits<Value>::max() otherwise. |
306 | 297 |
const Value INF; |
307 | 298 |
|
308 | 299 |
public: |
309 | 300 |
|
310 | 301 |
/// \name Named Template Parameters |
311 | 302 |
/// @{ |
312 | 303 |
|
313 | 304 |
template <typename T> |
314 | 305 |
struct SetLargeCostTraits : public Traits { |
... | ... |
@@ -329,33 +320,32 @@ |
329 | 320 |
|
330 | 321 |
/// @} |
331 | 322 |
|
332 | 323 |
protected: |
333 | 324 |
|
334 | 325 |
CostScaling() {} |
335 | 326 |
|
336 | 327 |
public: |
337 | 328 |
|
338 | 329 |
/// \brief Constructor. |
339 | 330 |
/// |
340 | 331 |
/// The constructor of the class. |
341 | 332 |
/// |
342 | 333 |
/// \param graph The digraph the algorithm runs on. |
343 | 334 |
CostScaling(const GR& graph) : |
344 | 335 |
_graph(graph), _node_id(graph), _arc_idf(graph), _arc_idb(graph), |
345 |
_cost_map(_cost_vec), _pi_map(_pi), |
|
346 | 336 |
INF(std::numeric_limits<Value>::has_infinity ? |
347 | 337 |
std::numeric_limits<Value>::infinity() : |
348 | 338 |
std::numeric_limits<Value>::max()) |
349 | 339 |
{ |
350 | 340 |
// Check the number types |
351 | 341 |
LEMON_ASSERT(std::numeric_limits<Value>::is_signed, |
352 | 342 |
"The flow type of CostScaling must be signed"); |
353 | 343 |
LEMON_ASSERT(std::numeric_limits<Cost>::is_signed, |
354 | 344 |
"The cost type of CostScaling must be signed"); |
355 | 345 |
|
356 | 346 |
// Reset data structures |
357 | 347 |
reset(); |
358 | 348 |
} |
359 | 349 |
|
360 | 350 |
/// \name Parameters |
361 | 351 |
/// The parameters of the algorithm can be specified using these |
... | ... |
@@ -606,35 +596,32 @@ |
606 | 596 |
_forward.resize(_res_arc_num); |
607 | 597 |
_source.resize(_res_arc_num); |
608 | 598 |
_target.resize(_res_arc_num); |
609 | 599 |
_reverse.resize(_res_arc_num); |
610 | 600 |
|
611 | 601 |
_lower.resize(_res_arc_num); |
612 | 602 |
_upper.resize(_res_arc_num); |
613 | 603 |
_scost.resize(_res_arc_num); |
614 | 604 |
_supply.resize(_res_node_num); |
615 | 605 |
|
616 | 606 |
_res_cap.resize(_res_arc_num); |
617 | 607 |
_cost.resize(_res_arc_num); |
618 | 608 |
_pi.resize(_res_node_num); |
619 | 609 |
_excess.resize(_res_node_num); |
620 | 610 |
_next_out.resize(_res_node_num); |
621 | 611 |
|
622 |
_arc_vec.reserve(_res_arc_num); |
|
623 |
_cost_vec.reserve(_res_arc_num); |
|
624 |
|
|
625 | 612 |
// Copy the graph |
626 | 613 |
int i = 0, j = 0, k = 2 * _arc_num + _node_num; |
627 | 614 |
for (NodeIt n(_graph); n != INVALID; ++n, ++i) { |
628 | 615 |
_node_id[n] = i; |
629 | 616 |
} |
630 | 617 |
i = 0; |
631 | 618 |
for (NodeIt n(_graph); n != INVALID; ++n, ++i) { |
632 | 619 |
_first_out[i] = j; |
633 | 620 |
for (OutArcIt a(_graph, n); a != INVALID; ++a, ++j) { |
634 | 621 |
_arc_idf[a] = j; |
635 | 622 |
_forward[j] = true; |
636 | 623 |
_source[j] = i; |
637 | 624 |
_target[j] = _node_id[_graph.runningNode(a)]; |
638 | 625 |
} |
639 | 626 |
for (InArcIt a(_graph, n); a != INVALID; ++a, ++j) { |
640 | 627 |
_arc_idb[a] = j; |
... | ... |
@@ -910,48 +897,89 @@ |
910 | 897 |
// Execute the algorithm and transform the results |
911 | 898 |
void start(Method method) { |
912 | 899 |
const int MAX_PARTIAL_PATH_LENGTH = 4; |
913 | 900 |
|
914 | 901 |
switch (method) { |
915 | 902 |
case PUSH: |
916 | 903 |
startPush(); |
917 | 904 |
break; |
918 | 905 |
case AUGMENT: |
919 | 906 |
startAugment(_res_node_num - 1); |
920 | 907 |
break; |
921 | 908 |
case PARTIAL_AUGMENT: |
922 | 909 |
startAugment(MAX_PARTIAL_PATH_LENGTH); |
923 | 910 |
break; |
924 | 911 |
} |
925 | 912 |
|
926 |
// Compute node potentials for the original costs |
|
927 |
_arc_vec.clear(); |
|
928 |
_cost_vec.clear(); |
|
929 |
for (int j = 0; j != _res_arc_num; ++j) { |
|
930 |
if (_res_cap[j] > 0) { |
|
931 |
_arc_vec.push_back(IntPair(_source[j], _target[j])); |
|
932 |
|
|
913 |
// Compute node potentials (dual solution) |
|
914 |
for (int i = 0; i != _res_node_num; ++i) { |
|
915 |
_pi[i] = static_cast<Cost>(_pi[i] / (_res_node_num * _alpha)); |
|
916 |
} |
|
917 |
bool optimal = true; |
|
918 |
for (int i = 0; optimal && i != _res_node_num; ++i) { |
|
919 |
LargeCost pi_i = _pi[i]; |
|
920 |
int last_out = _first_out[i+1]; |
|
921 |
for (int j = _first_out[i]; j != last_out; ++j) { |
|
922 |
if (_res_cap[j] > 0 && _scost[j] + pi_i - _pi[_target[j]] < 0) { |
|
923 |
optimal = false; |
|
924 |
break; |
|
925 |
} |
|
933 | 926 |
} |
934 | 927 |
} |
935 |
_sgr.build(_res_node_num, _arc_vec.begin(), _arc_vec.end()); |
|
936 | 928 |
|
937 |
typename BellmanFord<StaticDigraph, LargeCostArcMap> |
|
938 |
::template SetDistMap<LargeCostNodeMap>::Create bf(_sgr, _cost_map); |
|
939 |
bf.distMap(_pi_map); |
|
940 |
bf.init(0); |
|
941 |
|
|
929 |
if (!optimal) { |
|
930 |
// Compute node potentials for the original costs with BellmanFord |
|
931 |
// (if it is necessary) |
|
932 |
typedef std::pair<int, int> IntPair; |
|
933 |
StaticDigraph sgr; |
|
934 |
std::vector<IntPair> arc_vec; |
|
935 |
std::vector<LargeCost> cost_vec; |
|
936 |
LargeCostArcMap cost_map(cost_vec); |
|
937 |
|
|
938 |
arc_vec.clear(); |
|
939 |
cost_vec.clear(); |
|
940 |
for (int j = 0; j != _res_arc_num; ++j) { |
|
941 |
if (_res_cap[j] > 0) { |
|
942 |
int u = _source[j], v = _target[j]; |
|
943 |
arc_vec.push_back(IntPair(u, v)); |
|
944 |
cost_vec.push_back(_scost[j] + _pi[u] - _pi[v]); |
|
945 |
} |
|
946 |
} |
|
947 |
sgr.build(_res_node_num, arc_vec.begin(), arc_vec.end()); |
|
948 |
|
|
949 |
typename BellmanFord<StaticDigraph, LargeCostArcMap>::Create |
|
950 |
bf(sgr, cost_map); |
|
951 |
bf.init(0); |
|
952 |
bf.start(); |
|
953 |
|
|
954 |
for (int i = 0; i != _res_node_num; ++i) { |
|
955 |
_pi[i] += bf.dist(sgr.node(i)); |
|
956 |
} |
|
957 |
} |
|
958 |
|
|
959 |
// Shift potentials to meet the requirements of the GEQ type |
|
960 |
// optimality conditions |
|
961 |
LargeCost max_pot = _pi[_root]; |
|
962 |
for (int i = 0; i != _res_node_num; ++i) { |
|
963 |
if (_pi[i] > max_pot) max_pot = _pi[i]; |
|
964 |
} |
|
965 |
if (max_pot != 0) { |
|
966 |
for (int i = 0; i != _res_node_num; ++i) { |
|
967 |
_pi[i] -= max_pot; |
|
968 |
} |
|
969 |
} |
|
942 | 970 |
|
943 | 971 |
// Handle non-zero lower bounds |
944 | 972 |
if (_have_lower) { |
945 | 973 |
int limit = _first_out[_root]; |
946 | 974 |
for (int j = 0; j != limit; ++j) { |
947 | 975 |
if (!_forward[j]) _res_cap[j] += _lower[j]; |
948 | 976 |
} |
949 | 977 |
} |
950 | 978 |
} |
951 | 979 |
|
952 | 980 |
// Initialize a cost scaling phase |
953 | 981 |
void initPhase() { |
954 | 982 |
// Saturate arcs not satisfying the optimality condition |
955 | 983 |
for (int u = 0; u != _res_node_num; ++u) { |
956 | 984 |
int last_out = _first_out[u+1]; |
957 | 985 |
LargeCost pi_u = _pi[u]; |
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