Changeset 899:cc9e0c15d747 in lemon for lemon/cost_scaling.h
 Timestamp:
 02/12/10 22:24:26 (10 years ago)
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 default
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 902:d2bc45e8f6f2, 915:c2ff0a365245
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 898:75c97c3786d6 (diff), 897:7762cab7f372 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
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lemon/cost_scaling.h
r891 r899 337 337 LEMON_ASSERT(std::numeric_limits<Cost>::is_signed, 338 338 "The cost type of CostScaling must be signed"); 339 339 340 // Reset data structures 341 reset(); 342 } 343 344 /// \name Parameters 345 /// The parameters of the algorithm can be specified using these 346 /// functions. 347 348 /// @{ 349 350 /// \brief Set the lower bounds on the arcs. 351 /// 352 /// This function sets the lower bounds on the arcs. 353 /// If it is not used before calling \ref run(), the lower bounds 354 /// will be set to zero on all arcs. 355 /// 356 /// \param map An arc map storing the lower bounds. 357 /// Its \c Value type must be convertible to the \c Value type 358 /// of the algorithm. 359 /// 360 /// \return <tt>(*this)</tt> 361 template <typename LowerMap> 362 CostScaling& lowerMap(const LowerMap& map) { 363 _have_lower = true; 364 for (ArcIt a(_graph); a != INVALID; ++a) { 365 _lower[_arc_idf[a]] = map[a]; 366 _lower[_arc_idb[a]] = map[a]; 367 } 368 return *this; 369 } 370 371 /// \brief Set the upper bounds (capacities) on the arcs. 372 /// 373 /// This function sets the upper bounds (capacities) on the arcs. 374 /// If it is not used before calling \ref run(), the upper bounds 375 /// will be set to \ref INF on all arcs (i.e. the flow value will be 376 /// unbounded from above). 377 /// 378 /// \param map An arc map storing the upper bounds. 379 /// Its \c Value type must be convertible to the \c Value type 380 /// of the algorithm. 381 /// 382 /// \return <tt>(*this)</tt> 383 template<typename UpperMap> 384 CostScaling& upperMap(const UpperMap& map) { 385 for (ArcIt a(_graph); a != INVALID; ++a) { 386 _upper[_arc_idf[a]] = map[a]; 387 } 388 return *this; 389 } 390 391 /// \brief Set the costs of the arcs. 392 /// 393 /// This function sets the costs of the arcs. 394 /// If it is not used before calling \ref run(), the costs 395 /// will be set to \c 1 on all arcs. 396 /// 397 /// \param map An arc map storing the costs. 398 /// Its \c Value type must be convertible to the \c Cost type 399 /// of the algorithm. 400 /// 401 /// \return <tt>(*this)</tt> 402 template<typename CostMap> 403 CostScaling& costMap(const CostMap& map) { 404 for (ArcIt a(_graph); a != INVALID; ++a) { 405 _scost[_arc_idf[a]] = map[a]; 406 _scost[_arc_idb[a]] = map[a]; 407 } 408 return *this; 409 } 410 411 /// \brief Set the supply values of the nodes. 412 /// 413 /// This function sets the supply values of the nodes. 414 /// If neither this function nor \ref stSupply() is used before 415 /// calling \ref run(), the supply of each node will be set to zero. 416 /// 417 /// \param map A node map storing the supply values. 418 /// Its \c Value type must be convertible to the \c Value type 419 /// of the algorithm. 420 /// 421 /// \return <tt>(*this)</tt> 422 template<typename SupplyMap> 423 CostScaling& supplyMap(const SupplyMap& map) { 424 for (NodeIt n(_graph); n != INVALID; ++n) { 425 _supply[_node_id[n]] = map[n]; 426 } 427 return *this; 428 } 429 430 /// \brief Set single source and target nodes and a supply value. 431 /// 432 /// This function sets a single source node and a single target node 433 /// and the required flow value. 434 /// If neither this function nor \ref supplyMap() is used before 435 /// calling \ref run(), the supply of each node will be set to zero. 436 /// 437 /// Using this function has the same effect as using \ref supplyMap() 438 /// with such a map in which \c k is assigned to \c s, \c k is 439 /// assigned to \c t and all other nodes have zero supply value. 440 /// 441 /// \param s The source node. 442 /// \param t The target node. 443 /// \param k The required amount of flow from node \c s to node \c t 444 /// (i.e. the supply of \c s and the demand of \c t). 445 /// 446 /// \return <tt>(*this)</tt> 447 CostScaling& stSupply(const Node& s, const Node& t, Value k) { 448 for (int i = 0; i != _res_node_num; ++i) { 449 _supply[i] = 0; 450 } 451 _supply[_node_id[s]] = k; 452 _supply[_node_id[t]] = k; 453 return *this; 454 } 455 456 /// @} 457 458 /// \name Execution control 459 /// The algorithm can be executed using \ref run(). 460 461 /// @{ 462 463 /// \brief Run the algorithm. 464 /// 465 /// This function runs the algorithm. 466 /// The paramters can be specified using functions \ref lowerMap(), 467 /// \ref upperMap(), \ref costMap(), \ref supplyMap(), \ref stSupply(). 468 /// For example, 469 /// \code 470 /// CostScaling<ListDigraph> cs(graph); 471 /// cs.lowerMap(lower).upperMap(upper).costMap(cost) 472 /// .supplyMap(sup).run(); 473 /// \endcode 474 /// 475 /// This function can be called more than once. All the given parameters 476 /// are kept for the next call, unless \ref resetParams() or \ref reset() 477 /// is used, thus only the modified parameters have to be set again. 478 /// If the underlying digraph was also modified after the construction 479 /// of the class (or the last \ref reset() call), then the \ref reset() 480 /// function must be called. 481 /// 482 /// \param method The internal method that will be used in the 483 /// algorithm. For more information, see \ref Method. 484 /// \param factor The cost scaling factor. It must be larger than one. 485 /// 486 /// \return \c INFEASIBLE if no feasible flow exists, 487 /// \n \c OPTIMAL if the problem has optimal solution 488 /// (i.e. it is feasible and bounded), and the algorithm has found 489 /// optimal flow and node potentials (primal and dual solutions), 490 /// \n \c UNBOUNDED if the digraph contains an arc of negative cost 491 /// and infinite upper bound. It means that the objective function 492 /// is unbounded on that arc, however, note that it could actually be 493 /// bounded over the feasible flows, but this algroithm cannot handle 494 /// these cases. 495 /// 496 /// \see ProblemType, Method 497 /// \see resetParams(), reset() 498 ProblemType run(Method method = PARTIAL_AUGMENT, int factor = 8) { 499 _alpha = factor; 500 ProblemType pt = init(); 501 if (pt != OPTIMAL) return pt; 502 start(method); 503 return OPTIMAL; 504 } 505 506 /// \brief Reset all the parameters that have been given before. 507 /// 508 /// This function resets all the paramaters that have been given 509 /// before using functions \ref lowerMap(), \ref upperMap(), 510 /// \ref costMap(), \ref supplyMap(), \ref stSupply(). 511 /// 512 /// It is useful for multiple \ref run() calls. Basically, all the given 513 /// parameters are kept for the next \ref run() call, unless 514 /// \ref resetParams() or \ref reset() is used. 515 /// If the underlying digraph was also modified after the construction 516 /// of the class or the last \ref reset() call, then the \ref reset() 517 /// function must be used, otherwise \ref resetParams() is sufficient. 518 /// 519 /// For example, 520 /// \code 521 /// CostScaling<ListDigraph> cs(graph); 522 /// 523 /// // First run 524 /// cs.lowerMap(lower).upperMap(upper).costMap(cost) 525 /// .supplyMap(sup).run(); 526 /// 527 /// // Run again with modified cost map (resetParams() is not called, 528 /// // so only the cost map have to be set again) 529 /// cost[e] += 100; 530 /// cs.costMap(cost).run(); 531 /// 532 /// // Run again from scratch using resetParams() 533 /// // (the lower bounds will be set to zero on all arcs) 534 /// cs.resetParams(); 535 /// cs.upperMap(capacity).costMap(cost) 536 /// .supplyMap(sup).run(); 537 /// \endcode 538 /// 539 /// \return <tt>(*this)</tt> 540 /// 541 /// \see reset(), run() 542 CostScaling& resetParams() { 543 for (int i = 0; i != _res_node_num; ++i) { 544 _supply[i] = 0; 545 } 546 int limit = _first_out[_root]; 547 for (int j = 0; j != limit; ++j) { 548 _lower[j] = 0; 549 _upper[j] = INF; 550 _scost[j] = _forward[j] ? 1 : 1; 551 } 552 for (int j = limit; j != _res_arc_num; ++j) { 553 _lower[j] = 0; 554 _upper[j] = INF; 555 _scost[j] = 0; 556 _scost[_reverse[j]] = 0; 557 } 558 _have_lower = false; 559 return *this; 560 } 561 562 /// \brief Reset all the parameters that have been given before. 563 /// 564 /// This function resets all the paramaters that have been given 565 /// before using functions \ref lowerMap(), \ref upperMap(), 566 /// \ref costMap(), \ref supplyMap(), \ref stSupply(). 567 /// 568 /// It is useful for multiple run() calls. If this function is not 569 /// used, all the parameters given before are kept for the next 570 /// \ref run() call. 571 /// However, the underlying digraph must not be modified after this 572 /// class have been constructed, since it copies and extends the graph. 573 /// \return <tt>(*this)</tt> 574 CostScaling& reset() { 340 575 // Resize vectors 341 576 _node_num = countNodes(_graph); … … 405 640 406 641 // Reset parameters 407 reset(); 408 } 409 410 /// \name Parameters 411 /// The parameters of the algorithm can be specified using these 412 /// functions. 413 414 /// @{ 415 416 /// \brief Set the lower bounds on the arcs. 417 /// 418 /// This function sets the lower bounds on the arcs. 419 /// If it is not used before calling \ref run(), the lower bounds 420 /// will be set to zero on all arcs. 421 /// 422 /// \param map An arc map storing the lower bounds. 423 /// Its \c Value type must be convertible to the \c Value type 424 /// of the algorithm. 425 /// 426 /// \return <tt>(*this)</tt> 427 template <typename LowerMap> 428 CostScaling& lowerMap(const LowerMap& map) { 429 _have_lower = true; 430 for (ArcIt a(_graph); a != INVALID; ++a) { 431 _lower[_arc_idf[a]] = map[a]; 432 _lower[_arc_idb[a]] = map[a]; 433 } 434 return *this; 435 } 436 437 /// \brief Set the upper bounds (capacities) on the arcs. 438 /// 439 /// This function sets the upper bounds (capacities) on the arcs. 440 /// If it is not used before calling \ref run(), the upper bounds 441 /// will be set to \ref INF on all arcs (i.e. the flow value will be 442 /// unbounded from above). 443 /// 444 /// \param map An arc map storing the upper bounds. 445 /// Its \c Value type must be convertible to the \c Value type 446 /// of the algorithm. 447 /// 448 /// \return <tt>(*this)</tt> 449 template<typename UpperMap> 450 CostScaling& upperMap(const UpperMap& map) { 451 for (ArcIt a(_graph); a != INVALID; ++a) { 452 _upper[_arc_idf[a]] = map[a]; 453 } 454 return *this; 455 } 456 457 /// \brief Set the costs of the arcs. 458 /// 459 /// This function sets the costs of the arcs. 460 /// If it is not used before calling \ref run(), the costs 461 /// will be set to \c 1 on all arcs. 462 /// 463 /// \param map An arc map storing the costs. 464 /// Its \c Value type must be convertible to the \c Cost type 465 /// of the algorithm. 466 /// 467 /// \return <tt>(*this)</tt> 468 template<typename CostMap> 469 CostScaling& costMap(const CostMap& map) { 470 for (ArcIt a(_graph); a != INVALID; ++a) { 471 _scost[_arc_idf[a]] = map[a]; 472 _scost[_arc_idb[a]] = map[a]; 473 } 474 return *this; 475 } 476 477 /// \brief Set the supply values of the nodes. 478 /// 479 /// This function sets the supply values of the nodes. 480 /// If neither this function nor \ref stSupply() is used before 481 /// calling \ref run(), the supply of each node will be set to zero. 482 /// 483 /// \param map A node map storing the supply values. 484 /// Its \c Value type must be convertible to the \c Value type 485 /// of the algorithm. 486 /// 487 /// \return <tt>(*this)</tt> 488 template<typename SupplyMap> 489 CostScaling& supplyMap(const SupplyMap& map) { 490 for (NodeIt n(_graph); n != INVALID; ++n) { 491 _supply[_node_id[n]] = map[n]; 492 } 493 return *this; 494 } 495 496 /// \brief Set single source and target nodes and a supply value. 497 /// 498 /// This function sets a single source node and a single target node 499 /// and the required flow value. 500 /// If neither this function nor \ref supplyMap() is used before 501 /// calling \ref run(), the supply of each node will be set to zero. 502 /// 503 /// Using this function has the same effect as using \ref supplyMap() 504 /// with such a map in which \c k is assigned to \c s, \c k is 505 /// assigned to \c t and all other nodes have zero supply value. 506 /// 507 /// \param s The source node. 508 /// \param t The target node. 509 /// \param k The required amount of flow from node \c s to node \c t 510 /// (i.e. the supply of \c s and the demand of \c t). 511 /// 512 /// \return <tt>(*this)</tt> 513 CostScaling& stSupply(const Node& s, const Node& t, Value k) { 514 for (int i = 0; i != _res_node_num; ++i) { 515 _supply[i] = 0; 516 } 517 _supply[_node_id[s]] = k; 518 _supply[_node_id[t]] = k; 519 return *this; 520 } 521 522 /// @} 523 524 /// \name Execution control 525 /// The algorithm can be executed using \ref run(). 526 527 /// @{ 528 529 /// \brief Run the algorithm. 530 /// 531 /// This function runs the algorithm. 532 /// The paramters can be specified using functions \ref lowerMap(), 533 /// \ref upperMap(), \ref costMap(), \ref supplyMap(), \ref stSupply(). 534 /// For example, 535 /// \code 536 /// CostScaling<ListDigraph> cs(graph); 537 /// cs.lowerMap(lower).upperMap(upper).costMap(cost) 538 /// .supplyMap(sup).run(); 539 /// \endcode 540 /// 541 /// This function can be called more than once. All the parameters 542 /// that have been given are kept for the next call, unless 543 /// \ref reset() is called, thus only the modified parameters 544 /// have to be set again. See \ref reset() for examples. 545 /// However, the underlying digraph must not be modified after this 546 /// class have been constructed, since it copies and extends the graph. 547 /// 548 /// \param method The internal method that will be used in the 549 /// algorithm. For more information, see \ref Method. 550 /// \param factor The cost scaling factor. It must be larger than one. 551 /// 552 /// \return \c INFEASIBLE if no feasible flow exists, 553 /// \n \c OPTIMAL if the problem has optimal solution 554 /// (i.e. it is feasible and bounded), and the algorithm has found 555 /// optimal flow and node potentials (primal and dual solutions), 556 /// \n \c UNBOUNDED if the digraph contains an arc of negative cost 557 /// and infinite upper bound. It means that the objective function 558 /// is unbounded on that arc, however, note that it could actually be 559 /// bounded over the feasible flows, but this algroithm cannot handle 560 /// these cases. 561 /// 562 /// \see ProblemType, Method 563 ProblemType run(Method method = PARTIAL_AUGMENT, int factor = 8) { 564 _alpha = factor; 565 ProblemType pt = init(); 566 if (pt != OPTIMAL) return pt; 567 start(method); 568 return OPTIMAL; 569 } 570 571 /// \brief Reset all the parameters that have been given before. 572 /// 573 /// This function resets all the paramaters that have been given 574 /// before using functions \ref lowerMap(), \ref upperMap(), 575 /// \ref costMap(), \ref supplyMap(), \ref stSupply(). 576 /// 577 /// It is useful for multiple run() calls. If this function is not 578 /// used, all the parameters given before are kept for the next 579 /// \ref run() call. 580 /// However, the underlying digraph must not be modified after this 581 /// class have been constructed, since it copies and extends the graph. 582 /// 583 /// For example, 584 /// \code 585 /// CostScaling<ListDigraph> cs(graph); 586 /// 587 /// // First run 588 /// cs.lowerMap(lower).upperMap(upper).costMap(cost) 589 /// .supplyMap(sup).run(); 590 /// 591 /// // Run again with modified cost map (reset() is not called, 592 /// // so only the cost map have to be set again) 593 /// cost[e] += 100; 594 /// cs.costMap(cost).run(); 595 /// 596 /// // Run again from scratch using reset() 597 /// // (the lower bounds will be set to zero on all arcs) 598 /// cs.reset(); 599 /// cs.upperMap(capacity).costMap(cost) 600 /// .supplyMap(sup).run(); 601 /// \endcode 602 /// 603 /// \return <tt>(*this)</tt> 604 CostScaling& reset() { 605 for (int i = 0; i != _res_node_num; ++i) { 606 _supply[i] = 0; 607 } 608 int limit = _first_out[_root]; 609 for (int j = 0; j != limit; ++j) { 610 _lower[j] = 0; 611 _upper[j] = INF; 612 _scost[j] = _forward[j] ? 1 : 1; 613 } 614 for (int j = limit; j != _res_arc_num; ++j) { 615 _lower[j] = 0; 616 _upper[j] = INF; 617 _scost[j] = 0; 618 _scost[_reverse[j]] = 0; 619 } 620 _have_lower = false; 642 resetParams(); 621 643 return *this; 622 644 } 
lemon/cost_scaling.h
r898 r899 105 105 /// \tparam GR The digraph type the algorithm runs on. 106 106 /// \tparam V The number type used for flow amounts, capacity bounds 107 /// and supply values in the algorithm. By default it is \c int.107 /// and supply values in the algorithm. By default, it is \c int. 108 108 /// \tparam C The number type used for costs and potentials in the 109 /// algorithm. By default it is the same as \c V. 109 /// algorithm. By default, it is the same as \c V. 110 /// \tparam TR The traits class that defines various types used by the 111 /// algorithm. By default, it is \ref CostScalingDefaultTraits 112 /// "CostScalingDefaultTraits<GR, V, C>". 113 /// In most cases, this parameter should not be set directly, 114 /// consider to use the named template parameters instead. 110 115 /// 111 116 /// \warning Both number types must be signed and all input data must … … 137 142 /// 138 143 /// The large cost type used for internal computations. 139 /// Using the \ref CostScalingDefaultTraits "default traits class", 140 /// it is \c long \c long if the \c Cost type is integer, 144 /// By default, it is \c long \c long if the \c Cost type is integer, 141 145 /// otherwise it is \c double. 142 146 typedef typename TR::LargeCost LargeCost;
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