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src/work/marci/lp/max_flow_by_lp.cc
author alpar
Mon, 21 Feb 2005 14:59:12 +0000
changeset 1164 80bb73097736
parent 1025 3b1ad8bc21da
permissions -rw-r--r--
A year has passed again. 
     1 // -*- c++ -*-

     2 #include <iostream>

     3 #include <fstream>

     4 

     5 #include <lemon/smart_graph.h>

     6 #include <lemon/list_graph.h>

     7 #include <lemon/dimacs.h>

     8 #include <lemon/time_measure.h>

     9 //#include <graph_wrapper.h>

    10 #include <lemon/preflow.h>

    11 #include <augmenting_flow.h>

    12 //#include <preflow_res.h>

    13 //#include <lp_solver_wrapper_2.h>

    14 #include <min_cost_gen_flow.h>

    15 

    16 // Use a DIMACS max flow file as stdin.

    17 // max_flow_demo < dimacs_max_flow_file

    18 

    19 using namespace lemon;

    20 

    21 int main(int, char **) {

    22 

    23   typedef ListGraph MutableGraph;

    24   typedef ListGraph Graph;

    25   typedef Graph::Node Node;

    26   typedef Graph::Edge Edge;

    27   typedef Graph::EdgeIt EdgeIt;

    28 

    29   Graph g;

    30 

    31   Node s, t;

    32   Graph::EdgeMap<int> cap(g);

    33   //readDimacsMaxFlow(std::cin, g, s, t, cap);

    34   readDimacs(std::cin, g, cap, s, t);

    35   Timer ts;

    36   Graph::EdgeMap<int> flow(g); //0 flow

    37   Preflow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > 

    38     max_flow_test(g, s, t, cap, flow);

    39   AugmentingFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > 

    40     augmenting_flow_test(g, s, t, cap, flow);

    41   

    42   Graph::NodeMap<bool> cut(g);

    43 

    44   {

    45     std::cout << "preflow ..." << std::endl;

    46     ts.reset();

    47     max_flow_test.run();

    48     std::cout << "elapsed time: " << ts << std::endl;

    49     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;

    50     max_flow_test.minCut(cut);

    51 

    52     for (EdgeIt e(g); e!=INVALID; ++e) {

    53       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 

    54 	std::cout << "Slackness does not hold!" << std::endl;

    55       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 

    56 	std::cout << "Slackness does not hold!" << std::endl;

    57     }

    58   }

    59 

    60 //   {

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

    62 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);

    63 //     ts.reset();

    64 //     max_flow_test.preflow(Preflow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> >::GEN_FLOW);

    65 //     std::cout << "elapsed time: " << ts << std::endl;

    66 //     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;

    67 

    68 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {

    69 //       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 

    70 // 	std::cout << "Slackness does not hold!" << std::endl;

    71 //       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 

    72 // 	std::cout << "Slackness does not hold!" << std::endl;

    73 //     }

    74 //   }

    75 

    76 //   {

    77 //     std::cout << "wrapped preflow ..." << std::endl;

    78 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);

    79 //     ts.reset();

    80 //     pre_flow_res.run();

    81 //     std::cout << "elapsed time: " << ts << std::endl;

    82 //     std::cout << "flow value: "<< pre_flow_test.flowValue() << std::endl;

    83 //   }

    84 

    85   {

    86     std::cout << "physical blocking flow augmentation ..." << std::endl;

    87     for (EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0);

    88     ts.reset();

    89     int i=0;

    90     while (augmenting_flow_test.augmentOnBlockingFlow<MutableGraph>()) { ++i; }

    91     std::cout << "elapsed time: " << ts << std::endl;

    92     std::cout << "number of augmentation phases: " << i << std::endl; 

    93     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;

    94 

    95     for (EdgeIt e(g); e!=INVALID; ++e) {

    96       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 

    97 	std::cout << "Slackness does not hold!" << std::endl;

    98       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 

    99 	std::cout << "Slackness does not hold!" << std::endl;

   100     }

   101   }

   102 

   103 //   {

   104 //     std::cout << "faster physical blocking flow augmentation ..." << std::endl;

   105 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);

   106 //     ts.reset();

   107 //     int i=0;

   108 //     while (max_flow_test.augmentOnBlockingFlow1<MutableGraph>()) { ++i; }

   109 //     std::cout << "elapsed time: " << ts << std::endl;

   110 //     std::cout << "number of augmentation phases: " << i << std::endl; 

   111 //     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;

   112 //   }

   113 

   114   {

   115     std::cout << "on-the-fly blocking flow augmentation ..." << std::endl;

   116     for (EdgeIt e(g); e!=INVALID; ++e) flow.set(e, 0);

   117     ts.reset();

   118     int i=0;

   119     while (augmenting_flow_test.augmentOnBlockingFlow2()) { ++i; }

   120     std::cout << "elapsed time: " << ts << std::endl;

   121     std::cout << "number of augmentation phases: " << i << std::endl; 

   122     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;

   123 

   124     for (EdgeIt e(g); e!=INVALID; ++e) {

   125       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 

   126 	std::cout << "Slackness does not hold!" << std::endl;

   127       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 

   128 	std::cout << "Slackness does not hold!" << std::endl;

   129     }

   130   }

   131 

   132 //   {

   133 //     std::cout << "on-the-fly shortest path augmentation ..." << std::endl;

   134 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);

   135 //     ts.reset();

   136 //     int i=0;

   137 //     while (augmenting_flow_test.augmentOnShortestPath()) { ++i; }

   138 //     std::cout << "elapsed time: " << ts << std::endl;

   139 //     std::cout << "number of augmentation phases: " << i << std::endl; 

   140 //     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;

   141 

   142 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {

   143 //       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 

   144 // 	std::cout << "Slackness does not hold!" << std::endl;

   145 //       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 

   146 // 	std::cout << "Slackness does not hold!" << std::endl;

   147 //     }

   148 //   }

   149 

   150 //   {

   151 //     std::cout << "on-the-fly shortest path augmentation ..." << std::endl;

   152 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) flow.set(e, 0);

   153 //     ts.reset();

   154 //     int i=0;

   155 //     while (augmenting_flow_test.augmentOnShortestPath2()) { ++i; }

   156 //     std::cout << "elapsed time: " << ts << std::endl;

   157 //     std::cout << "number of augmentation phases: " << i << std::endl; 

   158 //     std::cout << "flow value: "<< augmenting_flow_test.flowValue() << std::endl;

   159 

   160 //     FOR_EACH_LOC(Graph::EdgeIt, e, g) {

   161 //       if (cut[g.source(e)] && !cut[g.target(e)] && !flow[e]==cap[e]) 

   162 // 	std::cout << "Slackness does not hold!" << std::endl;

   163 //       if (!cut[g.source(e)] && cut[g.target(e)] && flow[e]>0) 

   164 // 	std::cout << "Slackness does not hold!" << std::endl;

   165 //     }

   166 //   }

   167 

   168   ts.reset();

   169 

   170   Edge e=g.addEdge(t, s);

   171   Graph::EdgeMap<int> cost(g, 0);

   172   cost.set(e, -1);

   173   cap.set(e, 10000);

   174   typedef ConstMap<Node, int> Excess;

   175   Excess excess(0);

   176   typedef ConstMap<Edge, int> LCap;

   177   LCap lcap(0);

   178 

   179   MinCostGenFlow<Graph, int, Excess, LCap> 

   180     min_cost(g, excess, lcap, cap, flow, cost); 

   181   min_cost.feasible();

   182   min_cost.runByLP();

   183 

   184   std::cout << "elapsed time: " << ts << std::endl;

   185   std::cout << "flow value: "<< flow[e] << std::endl;

   186 }
lemon-0.x