// -*- c++ -*- // Use a DIMACS max flow file as stdin. // max_flow_demo < dimacs_max_flow_file #include #include #include #include #include #include #include #include #include using namespace lemon; int main(int, char **) { typedef ListGraph MutableGraph; typedef SmartGraph Graph; typedef Graph::Node Node; typedef Graph::EdgeIt EdgeIt; Graph g; Node s, t; Graph::EdgeMap cap(g); //readDimacsMaxFlow(std::cin, g, s, t, cap); readDimacs(std::cin, g, cap, s, t); Timer ts; Graph::EdgeMap flow(g); //0 flow Preflow, Graph::EdgeMap > max_flow_test(g, s, t, cap, flow); AugmentingFlow, Graph::EdgeMap > augmenting_flow_test(g, s, t, cap, flow); Graph::NodeMap cut(g); { std::cout << "preflow ..." << std::endl; ts.reset(); max_flow_test.run(); std::cout << "elapsed time: " << ts << std::endl; std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl; max_flow_test.minCut(cut); for(Graph::EdgeIt e(g); e!=INVALID; ++e) { if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) std::cout << "Slackness does not hold!" << std::endl; if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) std::cout << "Slackness does not hold!" << std::endl; } } { std::cout << "preflow ..." << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0); ts.reset(); max_flow_test.run(Preflow, Graph::EdgeMap >::GEN_FLOW); std::cout << "elapsed time: " << ts << std::endl; std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) { if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) std::cout << "Slackness does not hold!" << std::endl; if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) std::cout << "Slackness does not hold!" << std::endl; } } // { // std::cout << "wrapped preflow ..." << std::endl; // FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0); // ts.reset(); // pre_flow_res.run(); // std::cout << "elapsed time: " << ts << std::endl; // std::cout << "flow value: "<< pre_flow_test.flowValue() << std::endl; // } { std::cout << "physical blocking flow augmentation ..." << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0); ts.reset(); int i=0; while (augmenting_flow_test.augmentOnBlockingFlow()) { ++i; } std::cout << "elapsed time: " << ts << std::endl; std::cout << "number of augmentation phases: " << i << std::endl; std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) { if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) std::cout << "Slackness does not hold!" << std::endl; if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) std::cout << "Slackness does not hold!" << std::endl; } } { std::cout << "on-the-fly blocking flow augmentation ..." << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0); ts.reset(); int i=0; while (augmenting_flow_test.augmentOnBlockingFlow2()) { ++i; } std::cout << "elapsed time: " << ts << std::endl; std::cout << "number of augmentation phases: " << i << std::endl; std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) { if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) std::cout << "Slackness does not hold!" << std::endl; if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) std::cout << "Slackness does not hold!" << std::endl; } } { std::cout << "on-the-fly shortest path augmentation ..." << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0); ts.reset(); int i=0; while (augmenting_flow_test.augmentOnShortestPath()) { ++i; } std::cout << "elapsed time: " << ts << std::endl; std::cout << "number of augmentation phases: " << i << std::endl; std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) { if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) std::cout << "Slackness does not hold!" << std::endl; if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) std::cout << "Slackness does not hold!" << std::endl; } } { std::cout << "on-the-fly shortest path augmentation ..." << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0); ts.reset(); int i=0; while (augmenting_flow_test.augmentOnShortestPath2()) { ++i; } std::cout << "elapsed time: " << ts << std::endl; std::cout << "number of augmentation phases: " << i << std::endl; std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl; for(Graph::EdgeIt e(g); e!=INVALID; ++e) { if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) std::cout << "Slackness does not hold!" << std::endl; if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) std::cout << "Slackness does not hold!" << std::endl; } } return 0; }