r891:bb70ad62c95f
Thu, 24 Jun 2010 09:27:53
[Not Reviewed]
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| ... | ... |
@@ -549,30 +549,36 @@ |
| 549 | 549 |
/// |
| 550 | 550 |
/// The preflow algorithm consists of two phases, this method runs |
| 551 | 551 |
/// the first phase. After the first phase the maximum flow value |
| 552 | 552 |
/// and a minimum value cut can already be computed, although a |
| 553 | 553 |
/// maximum flow is not yet obtained. So after calling this method |
| 554 | 554 |
/// \ref flowValue() returns the value of a maximum flow and \ref |
| 555 | 555 |
/// minCut() returns a minimum cut. |
| 556 | 556 |
/// \pre One of the \ref init() functions must be called before |
| 557 | 557 |
/// using this function. |
| 558 | 558 |
void startFirstPhase() {
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| 559 | 559 |
_phase = true; |
| 560 | 560 |
|
| 561 |
Node n = _level->highestActive(); |
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| 562 |
int level = _level->highestActiveLevel(); |
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while ( |
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| 561 |
while (true) {
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|
| 564 | 562 |
int num = _node_num; |
| 565 | 563 |
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Node n = INVALID; |
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| 565 |
int level = -1; |
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|
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while (num > 0) {
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n = _level->highestActive(); |
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if (n == INVALID) goto first_phase_done; |
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level = _level->highestActiveLevel(); |
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--num; |
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|
|
| 567 | 573 |
Value excess = (*_excess)[n]; |
| 568 | 574 |
int new_level = _level->maxLevel(); |
| 569 | 575 |
|
| 570 | 576 |
for (OutArcIt e(_graph, n); e != INVALID; ++e) {
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| 571 | 577 |
Value rem = (*_capacity)[e] - (*_flow)[e]; |
| 572 | 578 |
if (!_tolerance.positive(rem)) continue; |
| 573 | 579 |
Node v = _graph.target(e); |
| 574 | 580 |
if ((*_level)[v] < level) {
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| 575 | 581 |
if (!_level->active(v) && v != _target) {
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| 576 | 582 |
_level->activate(v); |
| 577 | 583 |
} |
| 578 | 584 |
if (!_tolerance.less(rem, excess)) {
|
| ... | ... |
@@ -620,32 +626,40 @@ |
| 620 | 626 |
if (excess != 0) {
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| 621 | 627 |
if (new_level + 1 < _level->maxLevel()) {
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| 622 | 628 |
_level->liftHighestActive(new_level + 1); |
| 623 | 629 |
} else {
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| 624 | 630 |
_level->liftHighestActiveToTop(); |
| 625 | 631 |
} |
| 626 | 632 |
if (_level->emptyLevel(level)) {
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| 627 | 633 |
_level->liftToTop(level); |
| 628 | 634 |
} |
| 629 | 635 |
} else {
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| 630 | 636 |
_level->deactivate(n); |
| 631 | 637 |
} |
| 632 |
|
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n = _level->highestActive(); |
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level = _level->highestActiveLevel(); |
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--num; |
|
| 636 | 638 |
} |
| 637 | 639 |
|
| 638 | 640 |
num = _node_num * 20; |
| 639 |
while (num > 0 |
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while (num > 0) {
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while (level >= 0 && _level->activeFree(level)) {
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--level; |
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} |
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if (level == -1) {
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n = _level->highestActive(); |
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level = _level->highestActiveLevel(); |
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if (n == INVALID) goto first_phase_done; |
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} else {
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n = _level->activeOn(level); |
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} |
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--num; |
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|
|
| 640 | 654 |
Value excess = (*_excess)[n]; |
| 641 | 655 |
int new_level = _level->maxLevel(); |
| 642 | 656 |
|
| 643 | 657 |
for (OutArcIt e(_graph, n); e != INVALID; ++e) {
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| 644 | 658 |
Value rem = (*_capacity)[e] - (*_flow)[e]; |
| 645 | 659 |
if (!_tolerance.positive(rem)) continue; |
| 646 | 660 |
Node v = _graph.target(e); |
| 647 | 661 |
if ((*_level)[v] < level) {
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| 648 | 662 |
if (!_level->active(v) && v != _target) {
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| 649 | 663 |
_level->activate(v); |
| 650 | 664 |
} |
| 651 | 665 |
if (!_tolerance.less(rem, excess)) {
|
| ... | ... |
@@ -693,37 +707,27 @@ |
| 693 | 707 |
if (excess != 0) {
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| 694 | 708 |
if (new_level + 1 < _level->maxLevel()) {
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| 695 | 709 |
_level->liftActiveOn(level, new_level + 1); |
| 696 | 710 |
} else {
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| 697 | 711 |
_level->liftActiveToTop(level); |
| 698 | 712 |
} |
| 699 | 713 |
if (_level->emptyLevel(level)) {
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| 700 | 714 |
_level->liftToTop(level); |
| 701 | 715 |
} |
| 702 | 716 |
} else {
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| 703 | 717 |
_level->deactivate(n); |
| 704 | 718 |
} |
| 705 |
|
|
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while (level >= 0 && _level->activeFree(level)) {
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|
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--level; |
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} |
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if (level == -1) {
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n = _level->highestActive(); |
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level = _level->highestActiveLevel(); |
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} else {
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n = _level->activeOn(level); |
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} |
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--num; |
|
| 716 | 719 |
} |
| 717 | 720 |
} |
| 721 |
first_phase_done:; |
|
| 718 | 722 |
} |
| 719 | 723 |
|
| 720 | 724 |
/// \brief Starts the second phase of the preflow algorithm. |
| 721 | 725 |
/// |
| 722 | 726 |
/// The preflow algorithm consists of two phases, this method runs |
| 723 | 727 |
/// the second phase. After calling one of the \ref init() functions |
| 724 | 728 |
/// and \ref startFirstPhase() and then \ref startSecondPhase(), |
| 725 | 729 |
/// \ref flowMap() returns a maximum flow, \ref flowValue() returns the |
| 726 | 730 |
/// value of a maximum flow, \ref minCut() returns a minimum cut |
| 727 | 731 |
/// \pre One of the \ref init() functions and \ref startFirstPhase() |
| 728 | 732 |
/// must be called before using this function. |
| 729 | 733 |
void startSecondPhase() {
|
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