test/arborescence_test.cc
author deba
Fri, 14 Apr 2006 18:07:33 +0000
changeset 2051 08652c1763f6
child 2180 d5544c9409e4
permissions -rw-r--r--
MaxWeightedBipartiteMatching
MinCostMaxBipartiteMatching

Both algorithms are based on successive shortest
path algorithm with dijkstra shortest path
finding
     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 }