test/max_flow_test.cc
changeset 1172 0fdf84c79bc1
parent 1168 259e3a90ad97
child 1178 61fdd06833a6
     1.1 --- a/test/max_flow_test.cc	Fri Mar 23 15:37:23 2018 +0100
     1.2 +++ b/test/max_flow_test.cc	Fri Mar 23 15:39:54 2018 +0100
     1.3 @@ -26,6 +26,7 @@
     1.4  #include <lemon/concepts/maps.h>
     1.5  #include <lemon/lgf_reader.h>
     1.6  #include <lemon/elevator.h>
     1.7 +#include <lemon/tolerance.h>
     1.8  
     1.9  using namespace lemon;
    1.10  
    1.11 @@ -65,6 +66,37 @@
    1.12    "source 1\n"
    1.13    "target 8\n";
    1.14  
    1.15 +char test_lgf_float[] =
    1.16 +  "@nodes\n"
    1.17 +  "label\n"
    1.18 +  "0\n"
    1.19 +  "1\n"
    1.20 +  "2\n"
    1.21 +  "3\n"
    1.22 +  "4\n"
    1.23 +  "5\n"
    1.24 +  "6\n"
    1.25 +  "7\n"
    1.26 +  "8\n"
    1.27 +  "9\n"
    1.28 +  "@arcs\n"
    1.29 +  "      capacity\n"
    1.30 +  "0 1 0.1\n"
    1.31 +  "0 2 0.1\n"
    1.32 +  "0 3 0.1\n"
    1.33 +  "1 4 0.1\n"
    1.34 +  "2 4 0.1\n"
    1.35 +  "3 4 0.1\n"
    1.36 +  "4 5 0.3\n"
    1.37 +  "5 6 0.1\n"
    1.38 +  "5 7 0.1\n"
    1.39 +  "5 8 0.1\n"
    1.40 +  "6 9 0.1\n"
    1.41 +  "7 9 0.1\n"
    1.42 +  "8 9 0.1\n"
    1.43 +  "@attributes\n"
    1.44 +  "source 0\n"
    1.45 +  "target 9\n";
    1.46  
    1.47  // Checks the general interface of a max flow algorithm
    1.48  template <typename GR, typename CAP>
    1.49 @@ -165,8 +197,6 @@
    1.50    typedef int Value;
    1.51    typedef concepts::Digraph Digraph;
    1.52    typedef concepts::ReadMap<Digraph::Arc, Value> CapMap;
    1.53 -  typedef Elevator<Digraph, Digraph::Node> Elev;
    1.54 -  typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev;
    1.55  
    1.56    Digraph g;
    1.57    Digraph::Node n;
    1.58 @@ -184,13 +214,13 @@
    1.59  
    1.60  
    1.61  template <typename T>
    1.62 -T cutValue (const SmartDigraph& g,
    1.63 -              const SmartDigraph::NodeMap<bool>& cut,
    1.64 -              const SmartDigraph::ArcMap<T>& cap) {
    1.65 +T cutValue(const SmartDigraph& g,
    1.66 +           const SmartDigraph::NodeMap<bool>& cut,
    1.67 +           const SmartDigraph::ArcMap<T>& cap) {
    1.68  
    1.69 -  T c=0;
    1.70 -  for(SmartDigraph::ArcIt e(g); e!=INVALID; ++e) {
    1.71 -    if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e];
    1.72 +  T c = 0;
    1.73 +  for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) {
    1.74 +    if (cut[g.source(e)] && !cut[g.target(e)]) c += cap[e];
    1.75    }
    1.76    return c;
    1.77  }
    1.78 @@ -199,10 +229,11 @@
    1.79  bool checkFlow(const SmartDigraph& g,
    1.80                 const SmartDigraph::ArcMap<T>& flow,
    1.81                 const SmartDigraph::ArcMap<T>& cap,
    1.82 -               SmartDigraph::Node s, SmartDigraph::Node t) {
    1.83 +               SmartDigraph::Node s, SmartDigraph::Node t,
    1.84 +               const Tolerance<T>& tol) {
    1.85  
    1.86    for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) {
    1.87 -    if (flow[e] < 0 || flow[e] > cap[e]) return false;
    1.88 +    if (tol.negative(flow[e]) || tol.less(cap[e], flow[e])) return false;
    1.89    }
    1.90  
    1.91    for (SmartDigraph::NodeIt n(g); n != INVALID; ++n) {
    1.92 @@ -214,28 +245,29 @@
    1.93      for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) {
    1.94        sum -= flow[e];
    1.95      }
    1.96 -    if (sum != 0) return false;
    1.97 +    if (tol.nonZero(sum)) return false;
    1.98    }
    1.99    return true;
   1.100  }
   1.101  
   1.102 -void initFlowTest()
   1.103 +void checkInitPreflow()
   1.104  {
   1.105    DIGRAPH_TYPEDEFS(SmartDigraph);
   1.106  
   1.107    SmartDigraph g;
   1.108 -  SmartDigraph::ArcMap<int> cap(g),iflow(g);
   1.109 -  Node s=g.addNode(); Node t=g.addNode();
   1.110 -  Node n1=g.addNode(); Node n2=g.addNode();
   1.111 +  SmartDigraph::ArcMap<int> cap(g), iflow(g);
   1.112 +  Node s = g.addNode(); Node t = g.addNode();
   1.113 +  Node n1 = g.addNode(); Node n2 = g.addNode();
   1.114    Arc a;
   1.115 -  a=g.addArc(s,n1); cap[a]=20; iflow[a]=20;
   1.116 -  a=g.addArc(n1,n2); cap[a]=10; iflow[a]=0;
   1.117 -  a=g.addArc(n2,t); cap[a]=20; iflow[a]=0;
   1.118 +  a = g.addArc(s, n1); cap[a] = 20; iflow[a] = 20;
   1.119 +  a = g.addArc(n1, n2); cap[a] = 10; iflow[a] = 0;
   1.120 +  a = g.addArc(n2, t); cap[a] = 20; iflow[a] = 0;
   1.121  
   1.122 -  Preflow<SmartDigraph> pre(g,cap,s,t);
   1.123 +  Preflow<SmartDigraph> pre(g, cap, s, t);
   1.124    pre.init(iflow);
   1.125    pre.startFirstPhase();
   1.126 -  check(pre.flowValue() == 10, "The incorrect max flow value.");
   1.127 +
   1.128 +  check(pre.flowValue() == 10, "Incorrect max flow value.");
   1.129    check(pre.minCut(s), "Wrong min cut (Node s).");
   1.130    check(pre.minCut(n1), "Wrong min cut (Node n1).");
   1.131    check(!pre.minCut(n2), "Wrong min cut (Node n2).");
   1.132 @@ -243,7 +275,7 @@
   1.133  }
   1.134  
   1.135  template <typename MF, typename SF>
   1.136 -void checkMaxFlowAlg() {
   1.137 +void checkMaxFlowAlg(const char *input_lgf,  typename MF::Value expected) {
   1.138    typedef SmartDigraph Digraph;
   1.139    DIGRAPH_TYPEDEFS(Digraph);
   1.140  
   1.141 @@ -252,35 +284,36 @@
   1.142    typedef CapMap FlowMap;
   1.143    typedef BoolNodeMap CutMap;
   1.144  
   1.145 +  Tolerance<Value> tol;
   1.146 +
   1.147    Digraph g;
   1.148    Node s, t;
   1.149    CapMap cap(g);
   1.150 -  std::istringstream input(test_lgf);
   1.151 -  DigraphReader<Digraph>(g,input)
   1.152 +  std::istringstream input(input_lgf);
   1.153 +  DigraphReader<Digraph>(g, input)
   1.154        .arcMap("capacity", cap)
   1.155 -      .node("source",s)
   1.156 -      .node("target",t)
   1.157 +      .node("source", s)
   1.158 +      .node("target", t)
   1.159        .run();
   1.160  
   1.161    MF max_flow(g, cap, s, t);
   1.162    max_flow.run();
   1.163  
   1.164 -  check(checkFlow(g, max_flow.flowMap(), cap, s, t),
   1.165 +  check(!tol.different(expected, max_flow.flowValue()),
   1.166 +        "Incorrect max flow value.");
   1.167 +  check(checkFlow(g, max_flow.flowMap(), cap, s, t, tol),
   1.168          "The flow is not feasible.");
   1.169  
   1.170    CutMap min_cut(g);
   1.171    max_flow.minCutMap(min_cut);
   1.172    Value min_cut_value = cutValue(g, min_cut, cap);
   1.173  
   1.174 -  check(max_flow.flowValue() == min_cut_value,
   1.175 -        "The max flow value is not equal to the min cut value.");
   1.176 +  check(!tol.different(expected, min_cut_value),
   1.177 +        "Incorrect min cut value.");
   1.178  
   1.179    FlowMap flow(g);
   1.180 -  for (ArcIt e(g); e != INVALID; ++e) flow[e] = max_flow.flowMap()[e];
   1.181 -
   1.182 -  Value flow_value = max_flow.flowValue();
   1.183 -
   1.184 -  for (ArcIt e(g); e != INVALID; ++e) cap[e] = 2 * cap[e];
   1.185 +  for (ArcIt e(g); e != INVALID; ++e) flow[e] = 13 * max_flow.flowMap()[e];
   1.186 +  for (ArcIt e(g); e != INVALID; ++e) cap[e] = 17 * cap[e];
   1.187    max_flow.init(flow);
   1.188  
   1.189    SF::startFirstPhase(max_flow);       // start first phase of the algorithm
   1.190 @@ -289,23 +322,24 @@
   1.191    max_flow.minCutMap(min_cut1);
   1.192    min_cut_value = cutValue(g, min_cut1, cap);
   1.193  
   1.194 -  check(max_flow.flowValue() == min_cut_value &&
   1.195 -        min_cut_value == 2 * flow_value,
   1.196 -        "The max flow value or the min cut value is wrong.");
   1.197 +  check(!tol.different(17 * expected, max_flow.flowValue()),
   1.198 +        "Incorrect max flow value.");
   1.199 +  check(!tol.different(17 * expected, min_cut_value),
   1.200 +        "Incorrect min cut value.");
   1.201  
   1.202    SF::startSecondPhase(max_flow);       // start second phase of the algorithm
   1.203  
   1.204 -  check(checkFlow(g, max_flow.flowMap(), cap, s, t),
   1.205 +  check(checkFlow(g, max_flow.flowMap(), cap, s, t, tol),
   1.206          "The flow is not feasible.");
   1.207  
   1.208    CutMap min_cut2(g);
   1.209    max_flow.minCutMap(min_cut2);
   1.210    min_cut_value = cutValue(g, min_cut2, cap);
   1.211  
   1.212 -  check(max_flow.flowValue() == min_cut_value &&
   1.213 -        min_cut_value == 2 * flow_value,
   1.214 -        "The max flow value or the min cut value was not doubled");
   1.215 -
   1.216 +  check(!tol.different(17 * expected, max_flow.flowValue()),
   1.217 +        "Incorrect max flow value.");
   1.218 +  check(!tol.different(17 * expected, min_cut_value),
   1.219 +        "Incorrect min cut value.");
   1.220  
   1.221    max_flow.flowMap(flow);
   1.222  
   1.223 @@ -324,9 +358,9 @@
   1.224  
   1.225    CutMap min_cut3(g);
   1.226    max_flow.minCutMap(min_cut3);
   1.227 -  min_cut_value=cutValue(g, min_cut3, cap);
   1.228 +  min_cut_value = cutValue(g, min_cut3, cap);
   1.229  
   1.230 -  check(max_flow.flowValue() == min_cut_value,
   1.231 +  check(!tol.different(max_flow.flowValue(), min_cut_value),
   1.232          "The max flow value or the min cut value is wrong.");
   1.233  }
   1.234  
   1.235 @@ -379,17 +413,28 @@
   1.236    // Check Preflow
   1.237    typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<int> > PType1;
   1.238    typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<float> > PType2;
   1.239 -  checkMaxFlowAlg<PType1, PreflowStartFunctions<PType1> >();
   1.240 -  checkMaxFlowAlg<PType2, PreflowStartFunctions<PType2> >();
   1.241 -  initFlowTest();
   1.242 +  typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<double> > PType3;
   1.243 +
   1.244 +  checkMaxFlowAlg<PType1, PreflowStartFunctions<PType1> >(test_lgf, 13);
   1.245 +  checkMaxFlowAlg<PType2, PreflowStartFunctions<PType2> >(test_lgf, 13);
   1.246 +  checkMaxFlowAlg<PType3, PreflowStartFunctions<PType3> >(test_lgf, 13);
   1.247 +
   1.248 +  checkMaxFlowAlg<PType2, PreflowStartFunctions<PType2> >(test_lgf_float, 0.3);
   1.249 +  checkMaxFlowAlg<PType3, PreflowStartFunctions<PType3> >(test_lgf_float, 0.3);
   1.250 +
   1.251 +  checkInitPreflow();
   1.252  
   1.253    // Check EdmondsKarp
   1.254    typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<int> > EKType1;
   1.255    typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<float> > EKType2;
   1.256 -  checkMaxFlowAlg<EKType1, GeneralStartFunctions<EKType1> >();
   1.257 -  checkMaxFlowAlg<EKType2, GeneralStartFunctions<EKType2> >();
   1.258 +  typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<double> > EKType3;
   1.259  
   1.260 -  initFlowTest();
   1.261 +  checkMaxFlowAlg<EKType1, GeneralStartFunctions<EKType1> >(test_lgf, 13);
   1.262 +  checkMaxFlowAlg<EKType2, GeneralStartFunctions<EKType2> >(test_lgf, 13);
   1.263 +  checkMaxFlowAlg<EKType3, GeneralStartFunctions<EKType3> >(test_lgf, 13);
   1.264 +
   1.265 +  checkMaxFlowAlg<EKType2, GeneralStartFunctions<EKType2> >(test_lgf_float, 0.3);
   1.266 +  checkMaxFlowAlg<EKType3, GeneralStartFunctions<EKType3> >(test_lgf_float, 0.3);
   1.267  
   1.268    return 0;
   1.269  }