src/work/marci/lp/min_cost_gen_flow.h
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     1 // -*- c++ -*-
       
     2 #ifndef LEMON_MIN_COST_GEN_FLOW_H
       
     3 #define LEMON_MIN_COST_GEN_FLOW_H
       
     4 //#include <iostream>
       
     5 //#include <fstream>
       
     6 
       
     7 //#include <lemon/smart_graph.h>
       
     8 //#include <lemon/list_graph.h>
       
     9 //#include <lemon/dimacs.h>
       
    10 //#include <lemon/time_measure.h>
       
    11 //#include <graph_wrapper.h>
       
    12 //#include <lemon/preflow.h>
       
    13 //#include <augmenting_flow.h>
       
    14 //#include <preflow_res.h>
       
    15 #include <lemon/../work/marci/lp/lp_solver_wrapper.h>
       
    16 
       
    17 namespace lemon {
       
    18 
       
    19   template<typename Edge, typename EdgeIndexMap> 
       
    20   class PrimalMap {
       
    21   protected:
       
    22     LPSolverWrapper* lp;
       
    23     EdgeIndexMap* edge_index_map;
       
    24   public:
       
    25     PrimalMap(LPSolverWrapper& _lp, EdgeIndexMap& _edge_index_map) : 
       
    26       lp(&_lp), edge_index_map(&_edge_index_map) { }
       
    27     double operator[](Edge e) const { 
       
    28       return lp->getPrimal((*edge_index_map)[e]);
       
    29     }
       
    30   };
       
    31 
       
    32   // excess: rho-delta
       
    33   template <typename Graph, typename Num,
       
    34 	    typename Excess=typename Graph::template NodeMap<Num>, 
       
    35 	    typename LCapMap=typename Graph::template EdgeMap<Num>,
       
    36 	    typename CapMap=typename Graph::template EdgeMap<Num>,
       
    37             typename FlowMap=typename Graph::template EdgeMap<Num>,
       
    38 	    typename CostMap=typename Graph::template EdgeMap<Num> >
       
    39   class MinCostGenFlow {
       
    40   protected:
       
    41     const Graph& g;
       
    42     const Excess& excess;
       
    43     const LCapMap& lcapacity;
       
    44     const CapMap& capacity;
       
    45     FlowMap& flow;
       
    46     const CostMap& cost;
       
    47   public:
       
    48     MinCostGenFlow(const Graph& _g, const Excess& _excess, 
       
    49 		   const LCapMap& _lcapacity, const CapMap& _capacity, 
       
    50 		   FlowMap& _flow, 
       
    51 		   const CostMap& _cost) :
       
    52       g(_g), excess(_excess), lcapacity(_lcapacity),
       
    53       capacity(_capacity), flow(_flow), cost(_cost) { }
       
    54     void run() {
       
    55       LPSolverWrapper lp;
       
    56       lp.setMinimize();
       
    57       typedef LPSolverWrapper::ColIt ColIt;
       
    58       typedef LPSolverWrapper::RowIt RowIt;
       
    59       typedef typename Graph::template EdgeMap<ColIt> EdgeIndexMap;
       
    60       EdgeIndexMap edge_index_map(g);
       
    61       PrimalMap<typename Graph::Edge, EdgeIndexMap> lp_flow(lp, edge_index_map);
       
    62       for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {
       
    63 	ColIt col_it=lp.addCol();
       
    64 	edge_index_map.set(e, col_it);
       
    65 	if (lcapacity[e]==capacity[e])
       
    66 	  lp.setColBounds(col_it, LPX_FX, lcapacity[e], capacity[e]);
       
    67 	else 
       
    68 	  lp.setColBounds(col_it, LPX_DB, lcapacity[e], capacity[e]);
       
    69 	lp.setObjCoef(col_it, cost[e]);
       
    70       }
       
    71       for (typename Graph::NodeIt n(g); n!=INVALID; ++n) {
       
    72 	typename Graph::template EdgeMap<Num> coeffs(g, 0);
       
    73 	for (typename Graph::InEdgeIt e(g, n); e!=INVALID; ++e)
       
    74 	coeffs.set(e, coeffs[e]+1);
       
    75 	for (typename Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) 
       
    76 	coeffs.set(e, coeffs[e]-1);
       
    77 	RowIt row_it=lp.addRow();
       
    78 	typename std::vector< std::pair<ColIt, double> > row;
       
    79 	//std::cout << "node:" <<g.id(n)<<std::endl;
       
    80 	for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {
       
    81 	  if (coeffs[e]!=0) {
       
    82 	    //std::cout << " edge:" <<g.id(e)<<" "<<coeffs[e];
       
    83 	    row.push_back(std::make_pair(edge_index_map[e], coeffs[e]));
       
    84 	  }
       
    85 	}
       
    86 	//std::cout << std::endl;
       
    87 	lp.setRowCoeffs(row_it, row.begin(), row.end());
       
    88 	lp.setRowBounds(row_it, LPX_FX, 0.0, 0.0);
       
    89       }
       
    90       lp.solveSimplex();
       
    91       //std::cout << lp.colNum() << std::endl;
       
    92       //std::cout << lp.rowNum() << std::endl;
       
    93       //std::cout << "flow value: "<< lp.getObjVal() << std::endl;
       
    94       for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) 
       
    95       flow.set(e, lp_flow[e]);
       
    96     }
       
    97   };
       
    98 
       
    99 } // namespace lemon
       
   100 
       
   101 #endif //LEMON_MIN_COST_GEN_FLOW_H