test/max_flow_test.cc
changeset 1069 d1a48668ddb4
parent 1008 d216e1c8b3fa
child 1086 97f1760dcd13
equal deleted inserted replaced
12:83b06e975c83 0:0a4410be7bb3
    19 #include <iostream>
    19 #include <iostream>
    20 
    20 
    21 #include "test_tools.h"
    21 #include "test_tools.h"
    22 #include <lemon/smart_graph.h>
    22 #include <lemon/smart_graph.h>
    23 #include <lemon/preflow.h>
    23 #include <lemon/preflow.h>
       
    24 #include <lemon/edmonds_karp.h>
    24 #include <lemon/concepts/digraph.h>
    25 #include <lemon/concepts/digraph.h>
    25 #include <lemon/concepts/maps.h>
    26 #include <lemon/concepts/maps.h>
    26 #include <lemon/lgf_reader.h>
    27 #include <lemon/lgf_reader.h>
    27 #include <lemon/elevator.h>
    28 #include <lemon/elevator.h>
    28 
    29 
    62   "9 5 16    5\n"
    63   "9 5 16    5\n"
    63   "@attributes\n"
    64   "@attributes\n"
    64   "source 1\n"
    65   "source 1\n"
    65   "target 8\n";
    66   "target 8\n";
    66 
    67 
       
    68 
       
    69 // Checks the general interface of a max flow algorithm
       
    70 template <typename GR, typename CAP>
       
    71 struct MaxFlowClassConcept
       
    72 {
       
    73 
       
    74   template <typename MF>
       
    75   struct Constraints {
       
    76 
       
    77     typedef typename GR::Node Node;
       
    78     typedef typename GR::Arc Arc;
       
    79     typedef typename CAP::Value Value;
       
    80     typedef concepts::ReadWriteMap<Arc, Value> FlowMap;
       
    81     typedef concepts::WriteMap<Node, bool> CutMap;
       
    82 
       
    83     GR g;
       
    84     Node n;
       
    85     Arc e;
       
    86     CAP cap;
       
    87     FlowMap flow;
       
    88     CutMap cut;
       
    89     Value v;
       
    90     bool b;
       
    91 
       
    92     void constraints() {
       
    93       checkConcept<concepts::Digraph, GR>();
       
    94 
       
    95       const Constraints& me = *this;
       
    96 
       
    97       typedef typename MF
       
    98           ::template SetFlowMap<FlowMap>
       
    99           ::Create MaxFlowType;
       
   100       typedef typename MF::Create MaxFlowType2;
       
   101       MaxFlowType max_flow(me.g, me.cap, me.n, me.n);
       
   102       const MaxFlowType& const_max_flow = max_flow;
       
   103 
       
   104       max_flow
       
   105           .capacityMap(cap)
       
   106           .flowMap(flow)
       
   107           .source(n)
       
   108           .target(n);
       
   109 
       
   110       typename MaxFlowType::Tolerance tol = const_max_flow.tolerance();
       
   111       max_flow.tolerance(tol);
       
   112 
       
   113       max_flow.init();
       
   114       max_flow.init(cap);
       
   115       max_flow.run();
       
   116 
       
   117       v = const_max_flow.flowValue();
       
   118       v = const_max_flow.flow(e);
       
   119       const FlowMap& fm = const_max_flow.flowMap();
       
   120 
       
   121       b = const_max_flow.minCut(n);
       
   122       const_max_flow.minCutMap(cut);
       
   123 
       
   124       ignore_unused_variable_warning(fm);
       
   125     }
       
   126 
       
   127   };
       
   128 
       
   129 };
       
   130 
       
   131 // Checks the specific parts of Preflow's interface
    67 void checkPreflowCompile()
   132 void checkPreflowCompile()
    68 {
   133 {
    69   typedef int VType;
   134   typedef int Value;
    70   typedef concepts::Digraph Digraph;
   135   typedef concepts::Digraph Digraph;
    71 
   136   typedef concepts::ReadMap<Digraph::Arc, Value> CapMap;
    72   typedef Digraph::Node Node;
       
    73   typedef Digraph::Arc Arc;
       
    74   typedef concepts::ReadMap<Arc,VType> CapMap;
       
    75   typedef concepts::ReadWriteMap<Arc,VType> FlowMap;
       
    76   typedef concepts::WriteMap<Node,bool> CutMap;
       
    77 
       
    78   typedef Elevator<Digraph, Digraph::Node> Elev;
   137   typedef Elevator<Digraph, Digraph::Node> Elev;
    79   typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev;
   138   typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev;
    80 
   139 
    81   Digraph g;
   140   Digraph g;
    82   Node n;
   141   Digraph::Node n;
    83   Arc e;
       
    84   CapMap cap;
   142   CapMap cap;
    85   FlowMap flow;
       
    86   CutMap cut;
       
    87   VType v;
       
    88   bool b;
       
    89   ignore_unused_variable_warning(v,b);
       
    90 
   143 
    91   typedef Preflow<Digraph, CapMap>
   144   typedef Preflow<Digraph, CapMap>
    92             ::SetFlowMap<FlowMap>
   145       ::SetElevator<Elev>
    93             ::SetElevator<Elev>
   146       ::SetStandardElevator<LinkedElev>
    94             ::SetStandardElevator<LinkedElev>
   147       ::Create PreflowType;
    95             ::Create PreflowType;
       
    96   PreflowType preflow_test(g, cap, n, n);
   148   PreflowType preflow_test(g, cap, n, n);
    97   const PreflowType& const_preflow_test = preflow_test;
   149   const PreflowType& const_preflow_test = preflow_test;
    98 
   150 
    99   const PreflowType::Elevator& elev = const_preflow_test.elevator();
   151   const PreflowType::Elevator& elev = const_preflow_test.elevator();
   100   preflow_test.elevator(const_cast<PreflowType::Elevator&>(elev));
   152   preflow_test.elevator(const_cast<PreflowType::Elevator&>(elev));
   101   PreflowType::Tolerance tol = const_preflow_test.tolerance();
   153 
   102   preflow_test.tolerance(tol);
   154   bool b = preflow_test.init(cap);
   103 
       
   104   preflow_test
       
   105     .capacityMap(cap)
       
   106     .flowMap(flow)
       
   107     .source(n)
       
   108     .target(n);
       
   109 
       
   110   preflow_test.init();
       
   111   preflow_test.init(cap);
       
   112   preflow_test.startFirstPhase();
   155   preflow_test.startFirstPhase();
   113   preflow_test.startSecondPhase();
   156   preflow_test.startSecondPhase();
   114   preflow_test.run();
       
   115   preflow_test.runMinCut();
   157   preflow_test.runMinCut();
   116 
   158 
   117   v = const_preflow_test.flowValue();
   159   ignore_unused_variable_warning(b);
   118   v = const_preflow_test.flow(e);
   160 }
   119   const FlowMap& fm = const_preflow_test.flowMap();
   161 
   120   b = const_preflow_test.minCut(n);
   162 // Checks the specific parts of EdmondsKarp's interface
   121   const_preflow_test.minCutMap(cut);
   163 void checkEdmondsKarpCompile()
   122 
   164 {
   123   ignore_unused_variable_warning(fm);
   165   typedef int Value;
   124 }
   166   typedef concepts::Digraph Digraph;
   125 
   167   typedef concepts::ReadMap<Digraph::Arc, Value> CapMap;
   126 int cutValue (const SmartDigraph& g,
   168   typedef Elevator<Digraph, Digraph::Node> Elev;
       
   169   typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev;
       
   170 
       
   171   Digraph g;
       
   172   Digraph::Node n;
       
   173   CapMap cap;
       
   174 
       
   175   EdmondsKarp<Digraph, CapMap> ek_test(g, cap, n, n);
       
   176 
       
   177   ek_test.init(cap);
       
   178   bool b = ek_test.checkedInit(cap);
       
   179   b = ek_test.augment();
       
   180   ek_test.start();
       
   181 
       
   182   ignore_unused_variable_warning(b);
       
   183 }
       
   184 
       
   185 
       
   186 template <typename T>
       
   187 T cutValue (const SmartDigraph& g,
   127               const SmartDigraph::NodeMap<bool>& cut,
   188               const SmartDigraph::NodeMap<bool>& cut,
   128               const SmartDigraph::ArcMap<int>& cap) {
   189               const SmartDigraph::ArcMap<T>& cap) {
   129 
   190 
   130   int c=0;
   191   T c=0;
   131   for(SmartDigraph::ArcIt e(g); e!=INVALID; ++e) {
   192   for(SmartDigraph::ArcIt e(g); e!=INVALID; ++e) {
   132     if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e];
   193     if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e];
   133   }
   194   }
   134   return c;
   195   return c;
   135 }
   196 }
   136 
   197 
       
   198 template <typename T>
   137 bool checkFlow(const SmartDigraph& g,
   199 bool checkFlow(const SmartDigraph& g,
   138                const SmartDigraph::ArcMap<int>& flow,
   200                const SmartDigraph::ArcMap<T>& flow,
   139                const SmartDigraph::ArcMap<int>& cap,
   201                const SmartDigraph::ArcMap<T>& cap,
   140                SmartDigraph::Node s, SmartDigraph::Node t) {
   202                SmartDigraph::Node s, SmartDigraph::Node t) {
   141 
   203 
   142   for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) {
   204   for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) {
   143     if (flow[e] < 0 || flow[e] > cap[e]) return false;
   205     if (flow[e] < 0 || flow[e] > cap[e]) return false;
   144   }
   206   }
   145 
   207 
   146   for (SmartDigraph::NodeIt n(g); n != INVALID; ++n) {
   208   for (SmartDigraph::NodeIt n(g); n != INVALID; ++n) {
   147     if (n == s || n == t) continue;
   209     if (n == s || n == t) continue;
   148     int sum = 0;
   210     T sum = 0;
   149     for (SmartDigraph::OutArcIt e(g, n); e != INVALID; ++e) {
   211     for (SmartDigraph::OutArcIt e(g, n); e != INVALID; ++e) {
   150       sum += flow[e];
   212       sum += flow[e];
   151     }
   213     }
   152     for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) {
   214     for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) {
   153       sum -= flow[e];
   215       sum -= flow[e];
   178   check(pre.minCut(n1), "Wrong min cut (Node n1).");
   240   check(pre.minCut(n1), "Wrong min cut (Node n1).");
   179   check(!pre.minCut(n2), "Wrong min cut (Node n2).");
   241   check(!pre.minCut(n2), "Wrong min cut (Node n2).");
   180   check(!pre.minCut(t), "Wrong min cut (Node t).");
   242   check(!pre.minCut(t), "Wrong min cut (Node t).");
   181 }
   243 }
   182 
   244 
   183 
   245 template <typename MF, typename SF>
   184 int main() {
   246 void checkMaxFlowAlg() {
   185 
       
   186   typedef SmartDigraph Digraph;
   247   typedef SmartDigraph Digraph;
   187 
   248   DIGRAPH_TYPEDEFS(Digraph);
   188   typedef Digraph::Node Node;
   249 
   189   typedef Digraph::NodeIt NodeIt;
   250   typedef typename MF::Value Value;
   190   typedef Digraph::ArcIt ArcIt;
   251   typedef Digraph::ArcMap<Value> CapMap;
   191   typedef Digraph::ArcMap<int> CapMap;
   252   typedef CapMap FlowMap;
   192   typedef Digraph::ArcMap<int> FlowMap;
   253   typedef BoolNodeMap CutMap;
   193   typedef Digraph::NodeMap<bool> CutMap;
       
   194 
       
   195   typedef Preflow<Digraph, CapMap> PType;
       
   196 
   254 
   197   Digraph g;
   255   Digraph g;
   198   Node s, t;
   256   Node s, t;
   199   CapMap cap(g);
   257   CapMap cap(g);
   200   std::istringstream input(test_lgf);
   258   std::istringstream input(test_lgf);
   201   DigraphReader<Digraph>(g,input).
   259   DigraphReader<Digraph>(g,input)
   202     arcMap("capacity", cap).
   260       .arcMap("capacity", cap)
   203     node("source",s).
   261       .node("source",s)
   204     node("target",t).
   262       .node("target",t)
   205     run();
   263       .run();
   206 
   264 
   207   PType preflow_test(g, cap, s, t);
   265   MF max_flow(g, cap, s, t);
   208   preflow_test.run();
   266   max_flow.run();
   209 
   267 
   210   check(checkFlow(g, preflow_test.flowMap(), cap, s, t),
   268   check(checkFlow(g, max_flow.flowMap(), cap, s, t),
   211         "The flow is not feasible.");
   269         "The flow is not feasible.");
   212 
   270 
   213   CutMap min_cut(g);
   271   CutMap min_cut(g);
   214   preflow_test.minCutMap(min_cut);
   272   max_flow.minCutMap(min_cut);
   215   int min_cut_value=cutValue(g,min_cut,cap);
   273   Value min_cut_value = cutValue(g, min_cut, cap);
   216 
   274 
   217   check(preflow_test.flowValue() == min_cut_value,
   275   check(max_flow.flowValue() == min_cut_value,
   218         "The max flow value is not equal to the three min cut values.");
   276         "The max flow value is not equal to the min cut value.");
   219 
   277 
   220   FlowMap flow(g);
   278   FlowMap flow(g);
   221   for(ArcIt e(g); e!=INVALID; ++e) flow[e] = preflow_test.flowMap()[e];
   279   for (ArcIt e(g); e != INVALID; ++e) flow[e] = max_flow.flowMap()[e];
   222 
   280 
   223   int flow_value=preflow_test.flowValue();
   281   Value flow_value = max_flow.flowValue();
   224 
   282 
   225   for(ArcIt e(g); e!=INVALID; ++e) cap[e]=2*cap[e];
   283   for (ArcIt e(g); e != INVALID; ++e) cap[e] = 2 * cap[e];
   226   preflow_test.init(flow);
   284   max_flow.init(flow);
   227   preflow_test.startFirstPhase();
   285 
       
   286   SF::startFirstPhase(max_flow);       // start first phase of the algorithm
   228 
   287 
   229   CutMap min_cut1(g);
   288   CutMap min_cut1(g);
   230   preflow_test.minCutMap(min_cut1);
   289   max_flow.minCutMap(min_cut1);
   231   min_cut_value=cutValue(g,min_cut1,cap);
   290   min_cut_value = cutValue(g, min_cut1, cap);
   232 
   291 
   233   check(preflow_test.flowValue() == min_cut_value &&
   292   check(max_flow.flowValue() == min_cut_value &&
   234         min_cut_value == 2*flow_value,
   293         min_cut_value == 2 * flow_value,
   235         "The max flow value or the min cut value is wrong.");
   294         "The max flow value or the min cut value is wrong.");
   236 
   295 
   237   preflow_test.startSecondPhase();
   296   SF::startSecondPhase(max_flow);       // start second phase of the algorithm
   238 
   297 
   239   check(checkFlow(g, preflow_test.flowMap(), cap, s, t),
   298   check(checkFlow(g, max_flow.flowMap(), cap, s, t),
   240         "The flow is not feasible.");
   299         "The flow is not feasible.");
   241 
   300 
   242   CutMap min_cut2(g);
   301   CutMap min_cut2(g);
   243   preflow_test.minCutMap(min_cut2);
   302   max_flow.minCutMap(min_cut2);
   244   min_cut_value=cutValue(g,min_cut2,cap);
   303   min_cut_value = cutValue(g, min_cut2, cap);
   245 
   304 
   246   check(preflow_test.flowValue() == min_cut_value &&
   305   check(max_flow.flowValue() == min_cut_value &&
   247         min_cut_value == 2*flow_value,
   306         min_cut_value == 2 * flow_value,
   248         "The max flow value or the three min cut values were not doubled");
   307         "The max flow value or the min cut value was not doubled");
   249 
   308 
   250 
   309 
   251   preflow_test.flowMap(flow);
   310   max_flow.flowMap(flow);
   252 
   311 
   253   NodeIt tmp1(g,s);
   312   NodeIt tmp1(g, s);
   254   ++tmp1;
   313   ++tmp1;
   255   if ( tmp1 != INVALID ) s=tmp1;
   314   if (tmp1 != INVALID) s = tmp1;
   256 
   315 
   257   NodeIt tmp2(g,t);
   316   NodeIt tmp2(g, t);
   258   ++tmp2;
   317   ++tmp2;
   259   if ( tmp2 != INVALID ) t=tmp2;
   318   if (tmp2 != INVALID) t = tmp2;
   260 
   319 
   261   preflow_test.source(s);
   320   max_flow.source(s);
   262   preflow_test.target(t);
   321   max_flow.target(t);
   263 
   322 
   264   preflow_test.run();
   323   max_flow.run();
   265 
   324 
   266   CutMap min_cut3(g);
   325   CutMap min_cut3(g);
   267   preflow_test.minCutMap(min_cut3);
   326   max_flow.minCutMap(min_cut3);
   268   min_cut_value=cutValue(g,min_cut3,cap);
   327   min_cut_value=cutValue(g, min_cut3, cap);
   269 
   328 
   270 
   329   check(max_flow.flowValue() == min_cut_value,
   271   check(preflow_test.flowValue() == min_cut_value,
   330         "The max flow value or the min cut value is wrong.");
   272         "The max flow value or the three min cut values are incorrect.");
   331 }
       
   332 
       
   333 // Struct for calling start functions of a general max flow algorithm
       
   334 template <typename MF>
       
   335 struct GeneralStartFunctions {
       
   336 
       
   337   static void startFirstPhase(MF& mf) {
       
   338     mf.start();
       
   339   }
       
   340 
       
   341   static void startSecondPhase(MF& mf) {
       
   342     ignore_unused_variable_warning(mf);
       
   343   }
       
   344 
       
   345 };
       
   346 
       
   347 // Struct for calling start functions of Preflow
       
   348 template <typename MF>
       
   349 struct PreflowStartFunctions {
       
   350 
       
   351   static void startFirstPhase(MF& mf) {
       
   352     mf.startFirstPhase();
       
   353   }
       
   354 
       
   355   static void startSecondPhase(MF& mf) {
       
   356     mf.startSecondPhase();
       
   357   }
       
   358 
       
   359 };
       
   360 
       
   361 int main() {
       
   362 
       
   363   typedef concepts::Digraph GR;
       
   364   typedef concepts::ReadMap<GR::Arc, int> CM1;
       
   365   typedef concepts::ReadMap<GR::Arc, double> CM2;
       
   366 
       
   367   // Check the interface of Preflow
       
   368   checkConcept< MaxFlowClassConcept<GR, CM1>,
       
   369                 Preflow<GR, CM1> >();
       
   370   checkConcept< MaxFlowClassConcept<GR, CM2>,
       
   371                 Preflow<GR, CM2> >();
       
   372 
       
   373   // Check the interface of EdmondsKarp
       
   374   checkConcept< MaxFlowClassConcept<GR, CM1>,
       
   375                 EdmondsKarp<GR, CM1> >();
       
   376   checkConcept< MaxFlowClassConcept<GR, CM2>,
       
   377                 EdmondsKarp<GR, CM2> >();
       
   378 
       
   379   // Check Preflow
       
   380   typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<int> > PType1;
       
   381   typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<float> > PType2;
       
   382   checkMaxFlowAlg<PType1, PreflowStartFunctions<PType1> >();
       
   383   checkMaxFlowAlg<PType2, PreflowStartFunctions<PType2> >();
       
   384   initFlowTest();
       
   385   
       
   386   // Check EdmondsKarp
       
   387   typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<int> > EKType1;
       
   388   typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<float> > EKType2;
       
   389   checkMaxFlowAlg<EKType1, GeneralStartFunctions<EKType1> >();
       
   390   checkMaxFlowAlg<EKType2, GeneralStartFunctions<EKType2> >();
   273 
   391 
   274   initFlowTest();
   392   initFlowTest();
   275   
   393   
   276   return 0;
   394   return 0;
   277 }
   395 }