... | ... |
@@ -531,253 +531,257 @@ |
531 | 531 |
nqueue.push_back(v); |
532 | 532 |
} |
533 | 533 |
} |
534 | 534 |
} |
535 | 535 |
queue.swap(nqueue); |
536 | 536 |
} |
537 | 537 |
_level->initFinish(); |
538 | 538 |
|
539 | 539 |
for (OutArcIt e(_graph, _source); e != INVALID; ++e) { |
540 | 540 |
Value rem = (*_capacity)[e] - (*_flow)[e]; |
541 | 541 |
if (_tolerance.positive(rem)) { |
542 | 542 |
Node u = _graph.target(e); |
543 | 543 |
if ((*_level)[u] == _level->maxLevel()) continue; |
544 | 544 |
_flow->set(e, (*_capacity)[e]); |
545 | 545 |
(*_excess)[u] += rem; |
546 | 546 |
if (u != _target && !_level->active(u)) { |
547 | 547 |
_level->activate(u); |
548 | 548 |
} |
549 | 549 |
} |
550 | 550 |
} |
551 | 551 |
for (InArcIt e(_graph, _source); e != INVALID; ++e) { |
552 | 552 |
Value rem = (*_flow)[e]; |
553 | 553 |
if (_tolerance.positive(rem)) { |
554 | 554 |
Node v = _graph.source(e); |
555 | 555 |
if ((*_level)[v] == _level->maxLevel()) continue; |
556 | 556 |
_flow->set(e, 0); |
557 | 557 |
(*_excess)[v] += rem; |
558 | 558 |
if (v != _target && !_level->active(v)) { |
559 | 559 |
_level->activate(v); |
560 | 560 |
} |
561 | 561 |
} |
562 | 562 |
} |
563 | 563 |
return true; |
564 | 564 |
} |
565 | 565 |
|
566 | 566 |
/// \brief Starts the first phase of the preflow algorithm. |
567 | 567 |
/// |
568 | 568 |
/// The preflow algorithm consists of two phases, this method runs |
569 | 569 |
/// the first phase. After the first phase the maximum flow value |
570 | 570 |
/// and a minimum value cut can already be computed, although a |
571 | 571 |
/// maximum flow is not yet obtained. So after calling this method |
572 | 572 |
/// \ref flowValue() returns the value of a maximum flow and \ref |
573 | 573 |
/// minCut() returns a minimum cut. |
574 | 574 |
/// \pre One of the \ref init() functions must be called before |
575 | 575 |
/// using this function. |
576 | 576 |
void startFirstPhase() { |
577 | 577 |
_phase = true; |
578 | 578 |
|
579 |
Node n = _level->highestActive(); |
|
580 |
int level = _level->highestActiveLevel(); |
|
581 |
while ( |
|
579 |
while (true) { |
|
582 | 580 |
int num = _node_num; |
583 | 581 |
|
584 |
|
|
582 |
Node n = INVALID; |
|
583 |
int level = -1; |
|
584 |
|
|
585 |
while (num > 0) { |
|
586 |
n = _level->highestActive(); |
|
587 |
if (n == INVALID) goto first_phase_done; |
|
588 |
level = _level->highestActiveLevel(); |
|
589 |
--num; |
|
590 |
|
|
585 | 591 |
Value excess = (*_excess)[n]; |
586 | 592 |
int new_level = _level->maxLevel(); |
587 | 593 |
|
588 | 594 |
for (OutArcIt e(_graph, n); e != INVALID; ++e) { |
589 | 595 |
Value rem = (*_capacity)[e] - (*_flow)[e]; |
590 | 596 |
if (!_tolerance.positive(rem)) continue; |
591 | 597 |
Node v = _graph.target(e); |
592 | 598 |
if ((*_level)[v] < level) { |
593 | 599 |
if (!_level->active(v) && v != _target) { |
594 | 600 |
_level->activate(v); |
595 | 601 |
} |
596 | 602 |
if (!_tolerance.less(rem, excess)) { |
597 | 603 |
_flow->set(e, (*_flow)[e] + excess); |
598 | 604 |
(*_excess)[v] += excess; |
599 | 605 |
excess = 0; |
600 | 606 |
goto no_more_push_1; |
601 | 607 |
} else { |
602 | 608 |
excess -= rem; |
603 | 609 |
(*_excess)[v] += rem; |
604 | 610 |
_flow->set(e, (*_capacity)[e]); |
605 | 611 |
} |
606 | 612 |
} else if (new_level > (*_level)[v]) { |
607 | 613 |
new_level = (*_level)[v]; |
608 | 614 |
} |
609 | 615 |
} |
610 | 616 |
|
611 | 617 |
for (InArcIt e(_graph, n); e != INVALID; ++e) { |
612 | 618 |
Value rem = (*_flow)[e]; |
613 | 619 |
if (!_tolerance.positive(rem)) continue; |
614 | 620 |
Node v = _graph.source(e); |
615 | 621 |
if ((*_level)[v] < level) { |
616 | 622 |
if (!_level->active(v) && v != _target) { |
617 | 623 |
_level->activate(v); |
618 | 624 |
} |
619 | 625 |
if (!_tolerance.less(rem, excess)) { |
620 | 626 |
_flow->set(e, (*_flow)[e] - excess); |
621 | 627 |
(*_excess)[v] += excess; |
622 | 628 |
excess = 0; |
623 | 629 |
goto no_more_push_1; |
624 | 630 |
} else { |
625 | 631 |
excess -= rem; |
626 | 632 |
(*_excess)[v] += rem; |
627 | 633 |
_flow->set(e, 0); |
628 | 634 |
} |
629 | 635 |
} else if (new_level > (*_level)[v]) { |
630 | 636 |
new_level = (*_level)[v]; |
631 | 637 |
} |
632 | 638 |
} |
633 | 639 |
|
634 | 640 |
no_more_push_1: |
635 | 641 |
|
636 | 642 |
(*_excess)[n] = excess; |
637 | 643 |
|
638 | 644 |
if (excess != 0) { |
639 | 645 |
if (new_level + 1 < _level->maxLevel()) { |
640 | 646 |
_level->liftHighestActive(new_level + 1); |
641 | 647 |
} else { |
642 | 648 |
_level->liftHighestActiveToTop(); |
643 | 649 |
} |
644 | 650 |
if (_level->emptyLevel(level)) { |
645 | 651 |
_level->liftToTop(level); |
646 | 652 |
} |
647 | 653 |
} else { |
648 | 654 |
_level->deactivate(n); |
649 | 655 |
} |
650 |
|
|
651 |
n = _level->highestActive(); |
|
652 |
level = _level->highestActiveLevel(); |
|
653 |
--num; |
|
654 | 656 |
} |
655 | 657 |
|
656 | 658 |
num = _node_num * 20; |
657 |
while (num > 0 |
|
659 |
while (num > 0) { |
|
660 |
while (level >= 0 && _level->activeFree(level)) { |
|
661 |
--level; |
|
662 |
} |
|
663 |
if (level == -1) { |
|
664 |
n = _level->highestActive(); |
|
665 |
level = _level->highestActiveLevel(); |
|
666 |
if (n == INVALID) goto first_phase_done; |
|
667 |
} else { |
|
668 |
n = _level->activeOn(level); |
|
669 |
} |
|
670 |
--num; |
|
671 |
|
|
658 | 672 |
Value excess = (*_excess)[n]; |
659 | 673 |
int new_level = _level->maxLevel(); |
660 | 674 |
|
661 | 675 |
for (OutArcIt e(_graph, n); e != INVALID; ++e) { |
662 | 676 |
Value rem = (*_capacity)[e] - (*_flow)[e]; |
663 | 677 |
if (!_tolerance.positive(rem)) continue; |
664 | 678 |
Node v = _graph.target(e); |
665 | 679 |
if ((*_level)[v] < level) { |
666 | 680 |
if (!_level->active(v) && v != _target) { |
667 | 681 |
_level->activate(v); |
668 | 682 |
} |
669 | 683 |
if (!_tolerance.less(rem, excess)) { |
670 | 684 |
_flow->set(e, (*_flow)[e] + excess); |
671 | 685 |
(*_excess)[v] += excess; |
672 | 686 |
excess = 0; |
673 | 687 |
goto no_more_push_2; |
674 | 688 |
} else { |
675 | 689 |
excess -= rem; |
676 | 690 |
(*_excess)[v] += rem; |
677 | 691 |
_flow->set(e, (*_capacity)[e]); |
678 | 692 |
} |
679 | 693 |
} else if (new_level > (*_level)[v]) { |
680 | 694 |
new_level = (*_level)[v]; |
681 | 695 |
} |
682 | 696 |
} |
683 | 697 |
|
684 | 698 |
for (InArcIt e(_graph, n); e != INVALID; ++e) { |
685 | 699 |
Value rem = (*_flow)[e]; |
686 | 700 |
if (!_tolerance.positive(rem)) continue; |
687 | 701 |
Node v = _graph.source(e); |
688 | 702 |
if ((*_level)[v] < level) { |
689 | 703 |
if (!_level->active(v) && v != _target) { |
690 | 704 |
_level->activate(v); |
691 | 705 |
} |
692 | 706 |
if (!_tolerance.less(rem, excess)) { |
693 | 707 |
_flow->set(e, (*_flow)[e] - excess); |
694 | 708 |
(*_excess)[v] += excess; |
695 | 709 |
excess = 0; |
696 | 710 |
goto no_more_push_2; |
697 | 711 |
} else { |
698 | 712 |
excess -= rem; |
699 | 713 |
(*_excess)[v] += rem; |
700 | 714 |
_flow->set(e, 0); |
701 | 715 |
} |
702 | 716 |
} else if (new_level > (*_level)[v]) { |
703 | 717 |
new_level = (*_level)[v]; |
704 | 718 |
} |
705 | 719 |
} |
706 | 720 |
|
707 | 721 |
no_more_push_2: |
708 | 722 |
|
709 | 723 |
(*_excess)[n] = excess; |
710 | 724 |
|
711 | 725 |
if (excess != 0) { |
712 | 726 |
if (new_level + 1 < _level->maxLevel()) { |
713 | 727 |
_level->liftActiveOn(level, new_level + 1); |
714 | 728 |
} else { |
715 | 729 |
_level->liftActiveToTop(level); |
716 | 730 |
} |
717 | 731 |
if (_level->emptyLevel(level)) { |
718 | 732 |
_level->liftToTop(level); |
719 | 733 |
} |
720 | 734 |
} else { |
721 | 735 |
_level->deactivate(n); |
722 | 736 |
} |
723 |
|
|
724 |
while (level >= 0 && _level->activeFree(level)) { |
|
725 |
--level; |
|
726 | 737 |
} |
727 |
if (level == -1) { |
|
728 |
n = _level->highestActive(); |
|
729 |
level = _level->highestActiveLevel(); |
|
730 |
} else { |
|
731 |
n = _level->activeOn(level); |
|
732 | 738 |
} |
733 |
--num; |
|
734 |
} |
|
735 |
|
|
739 |
first_phase_done:; |
|
736 | 740 |
} |
737 | 741 |
|
738 | 742 |
/// \brief Starts the second phase of the preflow algorithm. |
739 | 743 |
/// |
740 | 744 |
/// The preflow algorithm consists of two phases, this method runs |
741 | 745 |
/// the second phase. After calling one of the \ref init() functions |
742 | 746 |
/// and \ref startFirstPhase() and then \ref startSecondPhase(), |
743 | 747 |
/// \ref flowMap() returns a maximum flow, \ref flowValue() returns the |
744 | 748 |
/// value of a maximum flow, \ref minCut() returns a minimum cut |
745 | 749 |
/// \pre One of the \ref init() functions and \ref startFirstPhase() |
746 | 750 |
/// must be called before using this function. |
747 | 751 |
void startSecondPhase() { |
748 | 752 |
_phase = false; |
749 | 753 |
|
750 | 754 |
typename Digraph::template NodeMap<bool> reached(_graph); |
751 | 755 |
for (NodeIt n(_graph); n != INVALID; ++n) { |
752 | 756 |
reached[n] = (*_level)[n] < _level->maxLevel(); |
753 | 757 |
} |
754 | 758 |
|
755 | 759 |
_level->initStart(); |
756 | 760 |
_level->initAddItem(_source); |
757 | 761 |
|
758 | 762 |
std::vector<Node> queue; |
759 | 763 |
queue.push_back(_source); |
760 | 764 |
reached[_source] = true; |
761 | 765 |
|
762 | 766 |
while (!queue.empty()) { |
763 | 767 |
_level->initNewLevel(); |
764 | 768 |
std::vector<Node> nqueue; |
765 | 769 |
for (int i = 0; i < int(queue.size()); ++i) { |
766 | 770 |
Node n = queue[i]; |
767 | 771 |
for (OutArcIt e(_graph, n); e != INVALID; ++e) { |
768 | 772 |
Node v = _graph.target(e); |
769 | 773 |
if (!reached[v] && _tolerance.positive((*_flow)[e])) { |
770 | 774 |
reached[v] = true; |
771 | 775 |
_level->initAddItem(v); |
772 | 776 |
nqueue.push_back(v); |
773 | 777 |
} |
774 | 778 |
} |
775 | 779 |
for (InArcIt e(_graph, n); e != INVALID; ++e) { |
776 | 780 |
Node u = _graph.source(e); |
777 | 781 |
if (!reached[u] && |
778 | 782 |
_tolerance.positive((*_capacity)[e] - (*_flow)[e])) { |
779 | 783 |
reached[u] = true; |
780 | 784 |
_level->initAddItem(u); |
781 | 785 |
nqueue.push_back(u); |
782 | 786 |
} |
783 | 787 |
} |
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