src/work/marci/preflow_bug.cc
author athos
Fri, 25 Mar 2005 15:32:05 +0000
changeset 1262 61f989e3e525
parent 921 818510fa3d99
permissions -rw-r--r--
This was a bug, I guess
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// -*- c++ -*-
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#include <iostream>
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#include <fstream>
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#include <sage_graph.h>
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#include <lemon/smart_graph.h>
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#include <lemon/dimacs.h>
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//#include <lemon/time_measure.h>
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//#include <graph_wrapper.h>
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#include <lemon/max_flow.h>
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//#include <preflow_res.h>
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#include <for_each_macros.h>
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#include <graph_concept.h>
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using std::cout;
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using std::endl;
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using namespace lemon;
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// Use a DIMACS min cost flow file as stdin.
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// read_dimacs_demo < dimacs_max_flow_file
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int main(int, char **) {
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  //typedef SageGraph MutableGraph;
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  //typedef FullFeatureGraphConcept Graph;
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  //typedef SmartGraph Graph;
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  typedef SageGraph Graph;
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  typedef Graph::Node Node;
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  typedef Graph::EdgeIt EdgeIt;
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  Graph g;
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  Node s, t;
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  Graph::EdgeMap<int> cap(g);
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  Graph::EdgeMap<int> flow(g); //0 flow
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  //readDimacs(std::cin, g, cap, s, t);
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  readDimacs(std::cin, g, cap, s, t, flow);
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//  Timer ts;
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  MaxFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > 
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    max_flow_test(g, s, t, cap, flow);
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  Graph::NodeMap<bool> cut(g);
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  {
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    Graph::EdgeIt e;
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    for (g.first(e); g.valid(e); g.next(e))
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      cout << 1+g.id(g.source(e)) << "->" << 1+g.id(g.target(e)) << " cap: " << cap[e] << " preflow: " << flow[e] << endl;
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  }
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  {
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    Graph::NodeIt n;
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    for (g.first(n); g.valid(n); g.next(n)) {
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      int a=0;
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      {
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	Graph::InEdgeIt e;
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	for (g.first(e, n); g.valid(e); g.next(e)) a+=flow[e];
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      }
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      {
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	Graph::OutEdgeIt e;
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	for (g.first(e, n); g.valid(e); g.next(e)) a-=flow[e];
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      }
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      cout << 1+g.id(n) << " excess: " << a << endl;
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    }
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  }
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  {
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//    std::cout << "preflow ..." << std::endl;
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//    ts.reset();
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    max_flow_test.preflowPhase1(MaxFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> >::PRE_FLOW);
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//    std::cout << "elapsed time: " << ts << std::endl;
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    std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
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    std::cout << "flow value 2: "<< max_flow_test.flowValue2() << std::endl;
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    max_flow_test.actMinCut(cut);
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    Graph::EdgeIt e;
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    for (g.first(e); g.valid(e); g.next(e)) {
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      if (cut[g.source(e)] && !cut[g.target(e)]) {
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	cout << 1+g.id(g.source(e)) << "->" << 1+g.id(g.target(e)) 
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	     << "(forward edge) flow: " << flow[e] 
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	     << " cap: " << cap[e]<< endl;
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	if (flow[e]!=cap[e]) 
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	std::cout << "Slackness does not hold!" << std::endl;
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      }
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      if (!cut[g.source(e)] && cut[g.target(e)]) {
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	cout << 1+g.id(g.source(e)) << "->" << 1+g.id(g.target(e)) 
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	     << "(backward edge) flow: " << flow[e] << endl;
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	if (flow[e]!=0) 
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	std::cout << "Slackness does not hold!" << std::endl;
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      }
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    }
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    Graph::NodeIt n;
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    for (g.first(n); g.valid(n); g.next(n)) {
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      if (cut[n]) 
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	cout << "in cut: " << 1+g.id(n) << endl;
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    }
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  }
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//   {
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//     std::cout << "preflow ..." << std::endl;
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//     ts.reset();
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//     max_flow_test.run();
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//     std::cout << "elapsed time: " << ts << std::endl;
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//     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
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//     max_flow_test.actMinCut(cut);
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
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//       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//     }
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//   }
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//   {
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//     std::cout << "preflow ..." << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
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//     ts.reset();
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//     max_flow_test.preflow(MaxFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> >::GEN_FLOW);
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//     std::cout << "elapsed time: " << ts << std::endl;
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//     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
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//       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//     }
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//   }
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// //   {
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// //     std::cout << "wrapped preflow ..." << std::endl;
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// //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
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// //     ts.reset();
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// //     pre_flow_res.run();
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// //     std::cout << "elapsed time: " << ts << std::endl;
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// //     std::cout << "flow value: "<< pre_flow_test.flowValue() << std::endl;
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// //   }
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//   {
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//     std::cout << "physical blocking flow augmentation ..." << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
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//     ts.reset();
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//     int i=0;
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//     while (augmenting_flow_test.augmentOnBlockingFlow<MutableGraph>()) { ++i; }
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//     std::cout << "elapsed time: " << ts << std::endl;
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//     std::cout << "number of augmentation phases: " << i << std::endl; 
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//     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
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//       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//     }
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//   }
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// //   {
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// //     std::cout << "faster physical blocking flow augmentation ..." << std::endl;
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// //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
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// //     ts.reset();
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// //     int i=0;
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// //     while (max_flow_test.augmentOnBlockingFlow1<MutableGraph>()) { ++i; }
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// //     std::cout << "elapsed time: " << ts << std::endl;
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// //     std::cout << "number of augmentation phases: " << i << std::endl; 
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// //     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
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// //   }
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//   {
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//     std::cout << "on-the-fly blocking flow augmentation ..." << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
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//     ts.reset();
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//     int i=0;
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//     while (augmenting_flow_test.augmentOnBlockingFlow2()) { ++i; }
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//     std::cout << "elapsed time: " << ts << std::endl;
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//     std::cout << "number of augmentation phases: " << i << std::endl; 
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//     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
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//       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//     }
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//   }
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//   {
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//     std::cout << "on-the-fly shortest path augmentation ..." << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
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//     ts.reset();
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//     int i=0;
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//     while (augmenting_flow_test.augmentOnShortestPath()) { ++i; }
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//     std::cout << "elapsed time: " << ts << std::endl;
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//     std::cout << "number of augmentation phases: " << i << std::endl; 
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//     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
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//       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//     }
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//   }
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//   {
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//     std::cout << "on-the-fly shortest path augmentation ..." << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
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//     ts.reset();
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//     int i=0;
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//     while (augmenting_flow_test.augmentOnShortestPath2()) { ++i; }
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//     std::cout << "elapsed time: " << ts << std::endl;
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//     std::cout << "number of augmentation phases: " << i << std::endl; 
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//     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
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//     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
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//       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
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// 	std::cout << "Slackness does not hold!" << std::endl;
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//     }
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//   }
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  return 0;
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}