marci@764: // -*- c++ -*-
marci@764: #include <iostream>
marci@764: #include <fstream>
marci@764: 
alpar@921: #include <lemon/smart_graph.h>
marci@1014: #include <lemon/list_graph.h>
alpar@921: #include <lemon/dimacs.h>
alpar@921: #include <lemon/time_measure.h>
marci@764: //#include <graph_wrapper.h>
marci@1014: #include <lemon/preflow.h>
marci@764: #include <augmenting_flow.h>
marci@764: //#include <preflow_res.h>
marci@764: #include <lp_solver_wrapper.h>
marci@764: 
marci@764: // Use a DIMACS max flow file as stdin.
marci@764: // max_flow_demo < dimacs_max_flow_file
marci@764: 
marci@1015: using namespace lemon;
marci@1015: 
marci@1015: namespace lemon {
marci@1015: 
marci@1015:   template<typename Edge, typename EdgeIndexMap> 
marci@1015:   class PrimalMap {
marci@1015:   protected:
marci@1015:     LPSolverWrapper* lp;
marci@1015:     EdgeIndexMap* edge_index_map;
marci@1015:   public:
marci@1015:     PrimalMap(LPSolverWrapper& _lp, EdgeIndexMap& _edge_index_map) : 
marci@1015:       lp(&_lp), edge_index_map(&_edge_index_map) { }
marci@1015:     double operator[](Edge e) const { 
marci@1015:       return lp->getPrimal((*edge_index_map)[e]);
marci@1015:     }
marci@1015:   };
marci@1015: 
marci@1015:   // excess: rho-delta
marci@1015:   template <typename Graph, typename Num,
marci@1015: 	    typename Excess=typename Graph::template NodeMap<Num>, 
marci@1015: 	    typename LCapMap=typename Graph::template EdgeMap<Num>,
marci@1015: 	    typename CapMap=typename Graph::template EdgeMap<Num>,
marci@1015:             typename FlowMap=typename Graph::template EdgeMap<Num>,
marci@1015: 	    typename CostMap=typename Graph::template EdgeMap<Num> >
marci@1015:   class MinCostGenFlow {
marci@1015:   protected:
marci@1015:     const Graph& g;
marci@1015:     const Excess& excess;
marci@1015:     const LCapMap& lcapacity;
marci@1015:     const CapMap& capacity;
marci@1015:     FlowMap& flow;
marci@1015:     const CostMap& cost;
marci@1015:   public:
marci@1015:     MinCostGenFlow(const Graph& _g, const Excess& _excess, 
marci@1015: 		   const LCapMap& _lcapacity, const CapMap& _capacity, 
marci@1015: 		   FlowMap& _flow, 
marci@1015: 		   const CostMap& _cost) :
marci@1015:       g(_g), excess(_excess), lcapacity(_lcapacity),
marci@1015:       capacity(_capacity), flow(_flow), cost(_cost) { }
marci@1015:     void run() {
marci@1015:       LPSolverWrapper lp;
marci@1015:       lp.setMinimize();
marci@1015:       typedef LPSolverWrapper::ColIt ColIt;
marci@1015:       typedef LPSolverWrapper::RowIt RowIt;
marci@1015:       typedef typename Graph::template EdgeMap<ColIt> EdgeIndexMap;
marci@1015:       EdgeIndexMap edge_index_map(g);
marci@1015:       PrimalMap<typename Graph::Edge, EdgeIndexMap> lp_flow(lp, edge_index_map);
marci@1015:       for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {
marci@1015: 	ColIt col_it=lp.addCol();
marci@1015: 	edge_index_map.set(e, col_it);
marci@1015: 	if (lcapacity[e]==capacity[e])
marci@1015: 	  lp.setColBounds(col_it, LPX_FX, lcapacity[e], capacity[e]);
marci@1015: 	else 
marci@1015: 	  lp.setColBounds(col_it, LPX_DB, lcapacity[e], capacity[e]);
marci@1015: 	lp.setObjCoef(col_it, cost[e]);
marci@1015:       }
marci@1015:       for (typename Graph::NodeIt n(g); n!=INVALID; ++n) {
marci@1015: 	typename Graph::template EdgeMap<Num> coeffs(g, 0);
marci@1015: 	for (typename Graph::InEdgeIt e(g, n); e!=INVALID; ++e)
marci@1015: 	coeffs.set(e, coeffs[e]+1);
marci@1015: 	for (typename Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) 
marci@1015: 	coeffs.set(e, coeffs[e]-1);
marci@1015: 	RowIt row_it=lp.addRow();
marci@1015: 	typename std::vector< std::pair<ColIt, double> > row;
marci@1015: 	//std::cout << "node:" <<g.id(n)<<std::endl;
marci@1015: 	for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {
marci@1015: 	  if (coeffs[e]!=0) {
marci@1015: 	    //std::cout << " edge:" <<g.id(e)<<" "<<coeffs[e];
marci@1015: 	    row.push_back(std::make_pair(edge_index_map[e], coeffs[e]));
marci@1015: 	  }
marci@1015: 	}
marci@1015: 	//std::cout << std::endl;
marci@1015: 	lp.setRowCoeffs(row_it, row.begin(), row.end());
marci@1015: 	lp.setRowBounds(row_it, LPX_FX, 0.0, 0.0);
marci@1015:       }
marci@1015:       lp.solveSimplex();
marci@1015:       //std::cout << lp.colNum() << std::endl;
marci@1015:       //std::cout << lp.rowNum() << std::endl;
marci@1015:       //std::cout << "flow value: "<< lp.getObjVal() << std::endl;
marci@1015:       for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) 
marci@1015:       flow.set(e, lp_flow[e]);
marci@1015:     }
marci@1015:   };
marci@1015: 
marci@1015: }
marci@764: 
marci@764: int main(int, char **) {
marci@764: 
marci@1014:   typedef ListGraph MutableGraph;
marci@1014:   typedef SmartGraph Graph;
marci@764:   typedef Graph::Node Node;
marci@1015:   typedef Graph::Edge Edge;
marci@764:   typedef Graph::EdgeIt EdgeIt;
marci@764: 
marci@764:   Graph g;
marci@764: 
marci@764:   Node s, t;
marci@764:   Graph::EdgeMap<int> cap(g);
marci@764:   //readDimacsMaxFlow(std::cin, g, s, t, cap);
marci@764:   readDimacs(std::cin, g, cap, s, t);
marci@764:   Timer ts;
marci@764:   Graph::EdgeMap<int> flow(g); //0 flow
marci@1014:   Preflow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > 
marci@764:     max_flow_test(g, s, t, cap, flow);
marci@764:   AugmentingFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > 
marci@764:     augmenting_flow_test(g, s, t, cap, flow);
marci@764:   
marci@764:   Graph::NodeMap<bool> cut(g);
marci@764: 
marci@764:   {
marci@764:     std::cout << "preflow ..." << std::endl;
marci@764:     ts.reset();
marci@764:     max_flow_test.run();
marci@764:     std::cout << "elapsed time: " << ts << std::endl;
marci@764:     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
marci@1014:     max_flow_test.minCut(cut);
marci@764: 
marci@1015:     for (EdgeIt e(g); e!=INVALID; ++e) {
alpar@986:       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
marci@764: 	std::cout << "Slackness does not hold!" << std::endl;
alpar@986:       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
marci@764: 	std::cout << "Slackness does not hold!" << std::endl;
marci@764:     }
marci@764:   }
marci@764: 
marci@764: //   {
marci@764: //     std::cout << "preflow ..." << std::endl;
marci@764: //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
marci@764: //     ts.reset();
marci@1014: //     max_flow_test.preflow(Preflow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> >::GEN_FLOW);
marci@764: //     std::cout << "elapsed time: " << ts << std::endl;
marci@764: //     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
marci@764: 
marci@764: //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
alpar@986: //       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
marci@764: // 	std::cout << "Slackness does not hold!" << std::endl;
alpar@986: //       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
marci@764: // 	std::cout << "Slackness does not hold!" << std::endl;
marci@764: //     }
marci@764: //   }
marci@764: 
marci@764: //   {
marci@764: //     std::cout << "wrapped preflow ..." << std::endl;
marci@764: //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
marci@764: //     ts.reset();
marci@764: //     pre_flow_res.run();
marci@764: //     std::cout << "elapsed time: " << ts << std::endl;
marci@764: //     std::cout << "flow value: "<< pre_flow_test.flowValue() << std::endl;
marci@764: //   }
marci@764: 
marci@764:   {
marci@764:     std::cout << "physical blocking flow augmentation ..." << std::endl;
marci@1015:     for (EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0);
marci@764:     ts.reset();
marci@764:     int i=0;
marci@764:     while (augmenting_flow_test.augmentOnBlockingFlow<MutableGraph>()) { ++i; }
marci@764:     std::cout << "elapsed time: " << ts << std::endl;
marci@764:     std::cout << "number of augmentation phases: " << i << std::endl; 
marci@764:     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
marci@764: 
marci@1015:     for (EdgeIt e(g); e!=INVALID; ++e) {
alpar@986:       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
marci@764: 	std::cout << "Slackness does not hold!" << std::endl;
alpar@986:       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
marci@764: 	std::cout << "Slackness does not hold!" << std::endl;
marci@764:     }
marci@764:   }
marci@764: 
marci@764: //   {
marci@764: //     std::cout << "faster physical blocking flow augmentation ..." << std::endl;
marci@764: //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
marci@764: //     ts.reset();
marci@764: //     int i=0;
marci@764: //     while (max_flow_test.augmentOnBlockingFlow1<MutableGraph>()) { ++i; }
marci@764: //     std::cout << "elapsed time: " << ts << std::endl;
marci@764: //     std::cout << "number of augmentation phases: " << i << std::endl; 
marci@764: //     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
marci@764: //   }
marci@764: 
marci@764:   {
marci@764:     std::cout << "on-the-fly blocking flow augmentation ..." << std::endl;
marci@1015:     for (EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0);
marci@764:     ts.reset();
marci@764:     int i=0;
marci@764:     while (augmenting_flow_test.augmentOnBlockingFlow2()) { ++i; }
marci@764:     std::cout << "elapsed time: " << ts << std::endl;
marci@764:     std::cout << "number of augmentation phases: " << i << std::endl; 
marci@764:     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
marci@764: 
marci@1015:     for (EdgeIt e(g); e!=INVALID; ++e) {
alpar@986:       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
marci@764: 	std::cout << "Slackness does not hold!" << std::endl;
alpar@986:       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
marci@764: 	std::cout << "Slackness does not hold!" << std::endl;
marci@764:     }
marci@764:   }
marci@764: 
marci@764: //   {
marci@764: //     std::cout << "on-the-fly shortest path augmentation ..." << std::endl;
marci@764: //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
marci@764: //     ts.reset();
marci@764: //     int i=0;
marci@764: //     while (augmenting_flow_test.augmentOnShortestPath()) { ++i; }
marci@764: //     std::cout << "elapsed time: " << ts << std::endl;
marci@764: //     std::cout << "number of augmentation phases: " << i << std::endl; 
marci@764: //     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
marci@764: 
marci@764: //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
alpar@986: //       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
marci@764: // 	std::cout << "Slackness does not hold!" << std::endl;
alpar@986: //       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
marci@764: // 	std::cout << "Slackness does not hold!" << std::endl;
marci@764: //     }
marci@764: //   }
marci@764: 
marci@764: //   {
marci@764: //     std::cout << "on-the-fly shortest path augmentation ..." << std::endl;
marci@764: //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
marci@764: //     ts.reset();
marci@764: //     int i=0;
marci@764: //     while (augmenting_flow_test.augmentOnShortestPath2()) { ++i; }
marci@764: //     std::cout << "elapsed time: " << ts << std::endl;
marci@764: //     std::cout << "number of augmentation phases: " << i << std::endl; 
marci@764: //     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
marci@764: 
marci@764: //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
alpar@986: //       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 
marci@764: // 	std::cout << "Slackness does not hold!" << std::endl;
alpar@986: //       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 
marci@764: // 	std::cout << "Slackness does not hold!" << std::endl;
marci@764: //     }
marci@764: //   }
marci@764: 
marci@764:   ts.reset();
marci@1015: 
marci@1015:   Edge e=g.addEdge(t, s);
marci@1015:   Graph::EdgeMap<int> cost(g, 0);
marci@1015:   cost.set(e, -1);
marci@1015:   cap.set(e, 10000);
marci@1015:   typedef ConstMap<Node, int> Excess;
marci@1015:   Excess excess(0);
marci@1015:   typedef ConstMap<Edge, int> LCap;
marci@1015:   LCap lcap(0);
marci@1015: 
marci@1015:   MinCostGenFlow<Graph, int, Excess, LCap> 
marci@1015:     min_cost(g, excess, lcap, cap, flow, cost); 
marci@1015:   min_cost.run();
marci@1015: 
marci@764:   std::cout << "elapsed time: " << ts << std::endl;
marci@1015:   std::cout << "flow value: "<< flow[e] << std::endl;
marci@764: }