r1030:a80381c43760
Mon, 28 Feb 2011 10:19:34
[Not Reviewed]
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| ... | ... |
@@ -538,33 +538,31 @@ |
| 538 | 538 |
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| 539 | 539 |
for (OutArcIt e(_graph, _source); e != INVALID; ++e) {
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| 540 | 540 |
Value rem = (*_capacity)[e] - (*_flow)[e]; |
| 541 | 541 |
if (_tolerance.positive(rem)) {
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| 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; |
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if (u != _target && !_level->active(u)) {
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_level->activate(u); |
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} |
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| 549 | 546 |
} |
| 550 | 547 |
} |
| 551 | 548 |
for (InArcIt e(_graph, _source); e != INVALID; ++e) {
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| 552 | 549 |
Value rem = (*_flow)[e]; |
| 553 | 550 |
if (_tolerance.positive(rem)) {
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| 554 | 551 |
Node v = _graph.source(e); |
| 555 | 552 |
if ((*_level)[v] == _level->maxLevel()) continue; |
| 556 | 553 |
_flow->set(e, 0); |
| 557 | 554 |
(*_excess)[v] += rem; |
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if (v != _target && !_level->active(v)) {
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_level->activate(v); |
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| 560 | 555 |
} |
| 561 | 556 |
} |
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for (NodeIt n(_graph); n != INVALID; ++n) |
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if(n!=_source && n!=_target && _tolerance.positive((*_excess)[n])) |
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_level->activate(n); |
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| 563 | 561 |
return true; |
| 564 | 562 |
} |
| 565 | 563 |
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| 566 | 564 |
/// \brief Starts the first phase of the preflow algorithm. |
| 567 | 565 |
/// |
| 568 | 566 |
/// The preflow algorithm consists of two phases, this method runs |
| 569 | 567 |
/// the first phase. After the first phase the maximum flow value |
| 570 | 568 |
/// and a minimum value cut can already be computed, although a |
| ... | ... |
@@ -151,16 +151,40 @@ |
| 151 | 151 |
for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) {
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| 152 | 152 |
sum -= flow[e]; |
| 153 | 153 |
} |
| 154 | 154 |
if (sum != 0) return false; |
| 155 | 155 |
} |
| 156 | 156 |
return true; |
| 157 | 157 |
} |
| 158 | 158 |
|
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void initFlowTest() |
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{
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DIGRAPH_TYPEDEFS(SmartDigraph); |
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SmartDigraph g; |
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SmartDigraph::ArcMap<int> cap(g),iflow(g); |
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Node s=g.addNode(); Node t=g.addNode(); |
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Node n1=g.addNode(); Node n2=g.addNode(); |
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Arc a; |
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a=g.addArc(s,n1); cap[a]=20; iflow[a]=20; |
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a=g.addArc(n1,n2); cap[a]=10; iflow[a]=0; |
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a=g.addArc(n2,t); cap[a]=20; iflow[a]=0; |
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Preflow<SmartDigraph> pre(g,cap,s,t); |
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pre.init(iflow); |
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pre.startFirstPhase(); |
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check(pre.flowValue() == 10, "The incorrect max flow value."); |
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check(pre.minCut(s), "Wrong min cut (Node s)."); |
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check(pre.minCut(n1), "Wrong min cut (Node n1)."); |
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check(!pre.minCut(n2), "Wrong min cut (Node n2)."); |
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check(!pre.minCut(t), "Wrong min cut (Node t)."); |
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} |
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| 159 | 183 |
int main() {
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| 160 | 184 |
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typedef SmartDigraph Digraph; |
| 162 | 186 |
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| 163 | 187 |
typedef Digraph::Node Node; |
| 164 | 188 |
typedef Digraph::NodeIt NodeIt; |
| 165 | 189 |
typedef Digraph::ArcIt ArcIt; |
| 166 | 190 |
typedef Digraph::ArcMap<int> CapMap; |
| ... | ... |
@@ -241,10 +265,12 @@ |
| 241 | 265 |
CutMap min_cut3(g); |
| 242 | 266 |
preflow_test.minCutMap(min_cut3); |
| 243 | 267 |
min_cut_value=cutValue(g,min_cut3,cap); |
| 244 | 268 |
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| 245 | 269 |
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check(preflow_test.flowValue() == min_cut_value, |
| 247 | 271 |
"The max flow value or the three min cut values are incorrect."); |
| 248 | 272 |
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initFlowTest(); |
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| 249 | 275 |
return 0; |
| 250 | 276 |
} |
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