src/work/marci/lp/max_flow_by_lp.cc
changeset 899 f485b3008cf5
child 921 818510fa3d99
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-1:000000000000 0:b9fd9b0217eb
       
     1 // -*- c++ -*-
       
     2 #include <iostream>
       
     3 #include <fstream>
       
     4 
       
     5 #include <sage_graph.h>
       
     6 #include <hugo/smart_graph.h>
       
     7 #include <hugo/dimacs.h>
       
     8 #include <hugo/time_measure.h>
       
     9 //#include <graph_wrapper.h>
       
    10 #include <hugo/max_flow.h>
       
    11 #include <augmenting_flow.h>
       
    12 //#include <preflow_res.h>
       
    13 #include <for_each_macros.h>
       
    14 #include <lp_solver_wrapper.h>
       
    15 
       
    16 using namespace hugo;
       
    17 
       
    18 // Use a DIMACS max flow file as stdin.
       
    19 // max_flow_demo < dimacs_max_flow_file
       
    20 
       
    21 template<typename Edge, typename EdgeIndexMap> 
       
    22 class PrimalMap {
       
    23 protected:
       
    24   LPSolverWrapper* lp;
       
    25   EdgeIndexMap* edge_index_map;
       
    26 public:
       
    27   PrimalMap(LPSolverWrapper& _lp, EdgeIndexMap& _edge_index_map) : 
       
    28     lp(&_lp), edge_index_map(&_edge_index_map) { }
       
    29   double operator[](Edge e) const { 
       
    30     return lp->getPrimal((*edge_index_map)[e]);
       
    31   }
       
    32 };
       
    33 
       
    34 int main(int, char **) {
       
    35 
       
    36   typedef SageGraph MutableGraph;
       
    37   //typedef SmartGraph Graph;
       
    38   typedef SageGraph Graph;
       
    39   typedef Graph::Node Node;
       
    40   typedef Graph::EdgeIt EdgeIt;
       
    41 
       
    42   Graph g;
       
    43 
       
    44   Node s, t;
       
    45   Graph::EdgeMap<int> cap(g);
       
    46   //readDimacsMaxFlow(std::cin, g, s, t, cap);
       
    47   readDimacs(std::cin, g, cap, s, t);
       
    48   Timer ts;
       
    49   Graph::EdgeMap<int> flow(g); //0 flow
       
    50   MaxFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > 
       
    51     max_flow_test(g, s, t, cap, flow);
       
    52   AugmentingFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > 
       
    53     augmenting_flow_test(g, s, t, cap, flow);
       
    54   
       
    55   Graph::NodeMap<bool> cut(g);
       
    56 
       
    57   {
       
    58     std::cout << "preflow ..." << std::endl;
       
    59     ts.reset();
       
    60     max_flow_test.run();
       
    61     std::cout << "elapsed time: " << ts << std::endl;
       
    62     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
       
    63     max_flow_test.actMinCut(cut);
       
    64 
       
    65     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
       
    66       if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) 
       
    67 	std::cout << "Slackness does not hold!" << std::endl;
       
    68       if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) 
       
    69 	std::cout << "Slackness does not hold!" << std::endl;
       
    70     }
       
    71   }
       
    72 
       
    73 //   {
       
    74 //     std::cout << "preflow ..." << std::endl;
       
    75 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
       
    76 //     ts.reset();
       
    77 //     max_flow_test.preflow(MaxFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> >::GEN_FLOW);
       
    78 //     std::cout << "elapsed time: " << ts << std::endl;
       
    79 //     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
       
    80 
       
    81 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
       
    82 //       if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) 
       
    83 // 	std::cout << "Slackness does not hold!" << std::endl;
       
    84 //       if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) 
       
    85 // 	std::cout << "Slackness does not hold!" << std::endl;
       
    86 //     }
       
    87 //   }
       
    88 
       
    89 //   {
       
    90 //     std::cout << "wrapped preflow ..." << std::endl;
       
    91 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
       
    92 //     ts.reset();
       
    93 //     pre_flow_res.run();
       
    94 //     std::cout << "elapsed time: " << ts << std::endl;
       
    95 //     std::cout << "flow value: "<< pre_flow_test.flowValue() << std::endl;
       
    96 //   }
       
    97 
       
    98   {
       
    99     std::cout << "physical blocking flow augmentation ..." << std::endl;
       
   100     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
       
   101     ts.reset();
       
   102     int i=0;
       
   103     while (augmenting_flow_test.augmentOnBlockingFlow<MutableGraph>()) { ++i; }
       
   104     std::cout << "elapsed time: " << ts << std::endl;
       
   105     std::cout << "number of augmentation phases: " << i << std::endl; 
       
   106     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
       
   107 
       
   108     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
       
   109       if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) 
       
   110 	std::cout << "Slackness does not hold!" << std::endl;
       
   111       if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) 
       
   112 	std::cout << "Slackness does not hold!" << std::endl;
       
   113     }
       
   114   }
       
   115 
       
   116 //   {
       
   117 //     std::cout << "faster physical blocking flow augmentation ..." << std::endl;
       
   118 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
       
   119 //     ts.reset();
       
   120 //     int i=0;
       
   121 //     while (max_flow_test.augmentOnBlockingFlow1<MutableGraph>()) { ++i; }
       
   122 //     std::cout << "elapsed time: " << ts << std::endl;
       
   123 //     std::cout << "number of augmentation phases: " << i << std::endl; 
       
   124 //     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
       
   125 //   }
       
   126 
       
   127   {
       
   128     std::cout << "on-the-fly blocking flow augmentation ..." << std::endl;
       
   129     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
       
   130     ts.reset();
       
   131     int i=0;
       
   132     while (augmenting_flow_test.augmentOnBlockingFlow2()) { ++i; }
       
   133     std::cout << "elapsed time: " << ts << std::endl;
       
   134     std::cout << "number of augmentation phases: " << i << std::endl; 
       
   135     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
       
   136 
       
   137     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
       
   138       if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) 
       
   139 	std::cout << "Slackness does not hold!" << std::endl;
       
   140       if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) 
       
   141 	std::cout << "Slackness does not hold!" << std::endl;
       
   142     }
       
   143   }
       
   144 
       
   145 //   {
       
   146 //     std::cout << "on-the-fly shortest path augmentation ..." << std::endl;
       
   147 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
       
   148 //     ts.reset();
       
   149 //     int i=0;
       
   150 //     while (augmenting_flow_test.augmentOnShortestPath()) { ++i; }
       
   151 //     std::cout << "elapsed time: " << ts << std::endl;
       
   152 //     std::cout << "number of augmentation phases: " << i << std::endl; 
       
   153 //     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
       
   154 
       
   155 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
       
   156 //       if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) 
       
   157 // 	std::cout << "Slackness does not hold!" << std::endl;
       
   158 //       if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) 
       
   159 // 	std::cout << "Slackness does not hold!" << std::endl;
       
   160 //     }
       
   161 //   }
       
   162 
       
   163 //   {
       
   164 //     std::cout << "on-the-fly shortest path augmentation ..." << std::endl;
       
   165 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);
       
   166 //     ts.reset();
       
   167 //     int i=0;
       
   168 //     while (augmenting_flow_test.augmentOnShortestPath2()) { ++i; }
       
   169 //     std::cout << "elapsed time: " << ts << std::endl;
       
   170 //     std::cout << "number of augmentation phases: " << i << std::endl; 
       
   171 //     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;
       
   172 
       
   173 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {
       
   174 //       if (cut[g.tail(e)] && !cut[g.head(e)] && !flow[e]==cap[e]) 
       
   175 // 	std::cout << "Slackness does not hold!" << std::endl;
       
   176 //       if (!cut[g.tail(e)] && cut[g.head(e)] && flow[e]>0) 
       
   177 // 	std::cout << "Slackness does not hold!" << std::endl;
       
   178 //     }
       
   179 //   }
       
   180 
       
   181   ts.reset();
       
   182   LPSolverWrapper lp;
       
   183   lp.setMaximize();
       
   184   typedef LPSolverWrapper::ColIt ColIt;
       
   185   typedef LPSolverWrapper::RowIt RowIt;
       
   186   typedef Graph::EdgeMap<ColIt> EdgeIndexMap;
       
   187   EdgeIndexMap edge_index_map(g);
       
   188   PrimalMap<Graph::Edge, EdgeIndexMap> lp_flow(lp, edge_index_map);
       
   189   Graph::EdgeIt e;
       
   190   for (g.first(e); g.valid(e); g.next(e)) {
       
   191     ColIt col_it=lp.addCol();
       
   192     edge_index_map.set(e, col_it);
       
   193     lp.setColBounds(col_it, LPX_DB, 0.0, cap[e]);
       
   194   }
       
   195   Graph::NodeIt n;
       
   196   for (g.first(n); g.valid(n); g.next(n)) {
       
   197     if (n!=s) {
       
   198       //hurokelek miatt
       
   199       Graph::EdgeMap<int> coeffs(g, 0);
       
   200       {
       
   201 	Graph::InEdgeIt e;
       
   202 	for (g.first(e, n); g.valid(e); g.next(e)) coeffs.set(e, coeffs[e]+1);
       
   203       }
       
   204       {
       
   205 	Graph::OutEdgeIt e;
       
   206 	for (g.first(e, n); g.valid(e); g.next(e)) coeffs.set(e, coeffs[e]-1);
       
   207       }
       
   208       if (n==t) {
       
   209 	Graph::EdgeIt e;
       
   210 	//std::vector< std::pair<ColIt, double> > row;
       
   211 	for (g.first(e); g.valid(e); g.next(e)) {
       
   212 	  if (coeffs[e]!=0) 
       
   213 	    lp.setObjCoef(edge_index_map[e], coeffs[e]);
       
   214 	}
       
   215       } else  {
       
   216 	RowIt row_it=lp.addRow();
       
   217 	Graph::EdgeIt e;
       
   218 	std::vector< std::pair<ColIt, double> > row;
       
   219 	for (g.first(e); g.valid(e); g.next(e)) {
       
   220 	  if (coeffs[e]!=0) 
       
   221 	    row.push_back(std::make_pair(edge_index_map[e], coeffs[e]));
       
   222 	}	
       
   223 	lp.setRowCoeffs(row_it, row.begin(), row.end());
       
   224 	lp.setRowBounds(row_it, LPX_FX, 0.0, 0.0);
       
   225       }
       
   226     }
       
   227   }
       
   228   lp.solveSimplex();
       
   229   std::cout << "flow value: "<< lp.getObjVal() << std::endl;
       
   230   std::cout << "elapsed time: " << ts << std::endl;
       
   231 
       
   232   return 0;
       
   233 }