test/arborescence_test.cc
changeset 2031 080d51024ac5
child 2180 d5544c9409e4
equal deleted inserted replaced
-1:000000000000 0:c439840dea46
       
     1 #include <iostream>
       
     2 #include <set>
       
     3 #include <vector>
       
     4 #include <iterator>
       
     5 
       
     6 #include <cmath>
       
     7 #include <cstdlib>
       
     8 
       
     9 #include <lemon/smart_graph.h>
       
    10 #include <lemon/min_cost_arborescence.h>
       
    11 
       
    12 #include <lemon/graph_utils.h>
       
    13 #include <lemon/time_measure.h>
       
    14 
       
    15 #include <lemon/tolerance.h>
       
    16 
       
    17 using namespace lemon;
       
    18 using namespace std;
       
    19 
       
    20 int main(int argc, const char *argv[]) {
       
    21   srand(time(0));
       
    22   typedef SmartGraph Graph;
       
    23   GRAPH_TYPEDEFS(Graph);
       
    24 
       
    25   typedef Graph::EdgeMap<double> CostMap;
       
    26 
       
    27   const int n = argc > 1 ? atoi(argv[1]) : 100;
       
    28   const int e = argc > 2 ? atoi(argv[2]) : (int)(n * log(n));
       
    29 
       
    30   Graph graph;
       
    31   CostMap cost(graph);
       
    32   vector<Node> nodes;
       
    33   
       
    34   for (int i = 0; i < n; ++i) {
       
    35     nodes.push_back(graph.addNode());
       
    36   }
       
    37 
       
    38   for (int i = 0; i < e; ++i) {
       
    39     int s = (int)(n * (double)rand() / (RAND_MAX + 1.0));
       
    40     int t = (int)(n * (double)rand() / (RAND_MAX + 1.0));
       
    41     double c = rand() / (1.0 + RAND_MAX) * 100.0 + 20.0;
       
    42     Edge edge = graph.addEdge(nodes[s], nodes[t]);
       
    43     cost[edge] = c;
       
    44   }
       
    45 
       
    46   Node source = nodes[(int)(n * (double)rand() / (RAND_MAX + 1.0))];
       
    47 
       
    48   MinCostArborescence<Graph, CostMap> mca(graph, cost);
       
    49   mca.run(source);
       
    50 
       
    51   vector<pair<double, set<Node> > > dualSolution(mca.dualSize());
       
    52 
       
    53   for (int i = 0; i < mca.dualSize(); ++i) {
       
    54     dualSolution[i].first = mca.dualValue(i);
       
    55     for (MinCostArborescence<Graph, CostMap>::DualIt it(mca, i); 
       
    56          it != INVALID; ++it) {
       
    57       dualSolution[i].second.insert(it);
       
    58     }
       
    59   }
       
    60 
       
    61   Tolerance<double> tolerance;
       
    62 
       
    63   for (EdgeIt it(graph); it != INVALID; ++it) {
       
    64     if (mca.reached(graph.source(it))) {
       
    65       double sum = 0.0;
       
    66       for (int i = 0; i < (int)dualSolution.size(); ++i) {
       
    67         if (dualSolution[i].second.find(graph.target(it)) 
       
    68             != dualSolution[i].second.end() &&
       
    69             dualSolution[i].second.find(graph.source(it)) 
       
    70             == dualSolution[i].second.end()) {
       
    71           sum += dualSolution[i].first;
       
    72         }
       
    73       }
       
    74       if (mca.arborescence(it)) {
       
    75         LEMON_ASSERT(!tolerance.less(sum, cost[it]), "INVALID DUAL");
       
    76       }
       
    77       LEMON_ASSERT(!tolerance.less(cost[it], sum), "INVALID DUAL");
       
    78     }
       
    79   }
       
    80 
       
    81 
       
    82   LEMON_ASSERT(!tolerance.different(mca.dualValue(), mca.arborescenceValue()),
       
    83                "INVALID DUAL");
       
    84 
       
    85 
       
    86   LEMON_ASSERT(mca.reached(source), "INVALID ARBORESCENCE");
       
    87   for (EdgeIt it(graph); it != INVALID; ++it) {
       
    88     LEMON_ASSERT(!mca.reached(graph.source(it)) || 
       
    89                  mca.reached(graph.target(it)), "INVALID ARBORESCENCE");
       
    90   }
       
    91 
       
    92   for (NodeIt it(graph); it != INVALID; ++it) {
       
    93     if (!mca.reached(it)) continue;
       
    94     int cnt = 0;
       
    95     for (InEdgeIt jt(graph, it); jt != INVALID; ++jt) {
       
    96       if (mca.arborescence(jt)) {
       
    97         ++cnt;
       
    98       }
       
    99     }
       
   100     LEMON_ASSERT((it == source ? cnt == 0 : cnt == 1), "INVALID ARBORESCENCE");
       
   101   }
       
   102   
       
   103   return 0;
       
   104 }