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src/work/marci/lp/min_cost_gen_flow.h
author marci
Wed, 01 Dec 2004 14:08:37 +0000
changeset 1026 bd7ea1a718e2
parent 1017 f588efc6d607
child 1028 2497336d7e14
permissions -rw-r--r--
More rational structure of classes in MergeGraphWrappers 
     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 <../merge_node_graph_wrapper.h>

    16 #include <lemon/../work/marci/lp/lp_solver_wrapper.h>

    17 

    18 namespace lemon {

    19 

    20   template<typename Edge, typename EdgeIndexMap> 

    21   class PrimalMap {

    22   protected:

    23     LPSolverWrapper* lp;

    24     EdgeIndexMap* edge_index_map;

    25   public:

    26     PrimalMap(LPSolverWrapper& _lp, EdgeIndexMap& _edge_index_map) : 

    27       lp(&_lp), edge_index_map(&_edge_index_map) { }

    28     double operator[](Edge e) const { 

    29       return lp->getPrimal((*edge_index_map)[e]);

    30     }

    31   };

    32 

    33   // excess: rho-delta

    34   template <typename Graph, typename Num,

    35 	    typename Excess=typename Graph::template NodeMap<Num>, 

    36 	    typename LCapMap=typename Graph::template EdgeMap<Num>,

    37 	    typename CapMap=typename Graph::template EdgeMap<Num>,

    38             typename FlowMap=typename Graph::template EdgeMap<Num>,

    39 	    typename CostMap=typename Graph::template EdgeMap<Num> >

    40   class MinCostGenFlow {

    41   protected:

    42     const Graph& g;

    43     const Excess& excess;

    44     const LCapMap& lcapacity;

    45     const CapMap& capacity;

    46     FlowMap& flow;

    47     const CostMap& cost;

    48   public:

    49     MinCostGenFlow(const Graph& _g, const Excess& _excess, 

    50 		   const LCapMap& _lcapacity, const CapMap& _capacity, 

    51 		   FlowMap& _flow, 

    52 		   const CostMap& _cost) :

    53       g(_g), excess(_excess), lcapacity(_lcapacity),

    54       capacity(_capacity), flow(_flow), cost(_cost) { }

    55     bool feasible() {

    56       //      std::cout << "making new vertices..." << std::endl; 

    57       typedef ListGraph Graph2;

    58       Graph2 g2;

    59       typedef MergeEdgeGraphWrapper<const Graph, Graph2> GW;

    60       //      std::cout << "merging..." << std::endl; 

    61       GW gw(g, g2);

    62       typename GW::Node s(INVALID, g2.addNode(), true);

    63       typename GW::Node t(INVALID, g2.addNode(), true);

    64       typedef SmartGraph Graph3;

    65       //      std::cout << "making extender graph..." << std::endl; 

    66       typedef NewEdgeSetGraphWrapper2<GW, Graph3> GWW;

    67 //       {

    68 // 	checkConcept<StaticGraph, GWW>();   

    69 //       }

    70       GWW gww(gw);

    71       typedef AugmentingGraphWrapper<GW, GWW> GWWW;

    72       GWWW gwww(gw, gww);

    73 

    74       //      std::cout << "making new edges..." << std::endl; 

    75       typename GWWW::template EdgeMap<Num> translated_cap(gwww);

    76 

    77       for (typename GW::EdgeIt e(gw); e!=INVALID; ++e)

    78       translated_cap.set(typename GWWW::Edge(e,INVALID,false), 

    79 			 capacity[e]-lcapacity[e]);

    80 

    81       Num expected=0;

    82 

    83       //      std::cout << "making new edges 2..." << std::endl; 

    84       for (typename Graph::NodeIt n(g); n!=INVALID; ++n) {

    85 	Num a=0;

    86 	for (typename Graph::InEdgeIt e(g, n); e!=INVALID; ++e)

    87 	  a+=lcapacity[e];

    88 	for (typename Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) 

    89 	  a-=lcapacity[e];

    90 	if (excess[n]>a) {

    91 	  typename GWW::Edge e=

    92 	    gww.addEdge(typename GW::Node(n,INVALID,false), t);

    93 	  translated_cap.set(typename GWWW::Edge(INVALID, e, true), 

    94 			     excess[n]-a);

    95 	}

    96 	if (excess[n]<a) {

    97 	  typename GWW::Edge e=

    98 	    gww.addEdge(s, typename GW::Node(n,INVALID,false));

    99 	  translated_cap.set(typename GWWW::Edge(INVALID, e, true), 

   100 			     a-excess[n]);

   101 	  expected+=a-excess[n];

   102 	}

   103       }

   104 

   105       //      std::cout << "preflow..." << std::endl; 

   106       typename GWWW::template EdgeMap<Num> translated_flow(gwww, 0);

   107       Preflow<GWWW, Num> preflow(gwww, s, t, 

   108 				 translated_cap, translated_flow);

   109       preflow.run();

   110       //      std::cout << "fv: " << preflow.flowValue() << std::endl; 

   111       //      std::cout << "expected: " << expected << std::endl; 

   112 

   113       for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {

   114 	typename GW::Edge ew(e, INVALID, false);

   115 	typename GWWW::Edge ewww(ew, INVALID, false);

   116 	flow.set(e, translated_flow[ewww]+lcapacity[e]);

   117       }

   118       return (expected>=preflow.flowValue());

   119     }

   120     void run() {

   121       LPSolverWrapper lp;

   122       lp.setMinimize();

   123       typedef LPSolverWrapper::ColIt ColIt;

   124       typedef LPSolverWrapper::RowIt RowIt;

   125       typedef typename Graph::template EdgeMap<ColIt> EdgeIndexMap;

   126       EdgeIndexMap edge_index_map(g);

   127       PrimalMap<typename Graph::Edge, EdgeIndexMap> lp_flow(lp, edge_index_map);

   128       for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {

   129 	ColIt col_it=lp.addCol();

   130 	edge_index_map.set(e, col_it);

   131 	if (lcapacity[e]==capacity[e])

   132 	  lp.setColBounds(col_it, LPX_FX, lcapacity[e], capacity[e]);

   133 	else 

   134 	  lp.setColBounds(col_it, LPX_DB, lcapacity[e], capacity[e]);

   135 	lp.setObjCoef(col_it, cost[e]);

   136       }

   137       for (typename Graph::NodeIt n(g); n!=INVALID; ++n) {

   138 	typename Graph::template EdgeMap<Num> coeffs(g, 0);

   139 	for (typename Graph::InEdgeIt e(g, n); e!=INVALID; ++e)

   140 	coeffs.set(e, coeffs[e]+1);

   141 	for (typename Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) 

   142 	coeffs.set(e, coeffs[e]-1);

   143 	RowIt row_it=lp.addRow();

   144 	typename std::vector< std::pair<ColIt, double> > row;

   145 	//std::cout << "node:" <<g.id(n)<<std::endl;

   146 	for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {

   147 	  if (coeffs[e]!=0) {

   148 	    //std::cout << " edge:" <<g.id(e)<<" "<<coeffs[e];

   149 	    row.push_back(std::make_pair(edge_index_map[e], coeffs[e]));

   150 	  }

   151 	}

   152 	//std::cout << std::endl;

   153 	lp.setRowCoeffs(row_it, row.begin(), row.end());

   154 	lp.setRowBounds(row_it, LPX_FX, 0.0, 0.0);

   155       }

   156       lp.solveSimplex();

   157       //std::cout << lp.colNum() << std::endl;

   158       //std::cout << lp.rowNum() << std::endl;

   159       //std::cout << "flow value: "<< lp.getObjVal() << std::endl;

   160       for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) 

   161       flow.set(e, lp_flow[e]);

   162     }

   163   };

   164 

   165 } // namespace lemon

   166 

   167 #endif //LEMON_MIN_COST_GEN_FLOW_H
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