lemon/bipartite_matching.h
changeset 2115 4cd528a30ec1
parent 2051 08652c1763f6
child 2136 4f64d6b3e9ec
equal deleted inserted replaced
1:3bcda3541cca 2:07146d970d32
   326 
   326 
   327     /// \brief Runs the algorithm.
   327     /// \brief Runs the algorithm.
   328     ///
   328     ///
   329     /// It just initalize the algorithm and then start it.
   329     /// It just initalize the algorithm and then start it.
   330     void run() {
   330     void run() {
   331       init();
   331       greedyInit();
   332       start();
   332       start();
   333     }
   333     }
   334 
   334 
   335     /// @}
   335     /// @}
   336 
   336 
   347     /// The minimum covering set problem is the dual solution of the
   347     /// The minimum covering set problem is the dual solution of the
   348     /// maximum bipartite matching. It provides an solution for this
   348     /// maximum bipartite matching. It provides an solution for this
   349     /// problem what is proof of the optimality of the matching.
   349     /// problem what is proof of the optimality of the matching.
   350     /// \return The size of the cover set.
   350     /// \return The size of the cover set.
   351     template <typename CoverMap>
   351     template <typename CoverMap>
   352     int coverSet(CoverMap& covering) {
   352     int coverSet(CoverMap& covering) const {
   353 
   353 
   354       typename Graph::template ANodeMap<bool> areached(*graph, false);
   354       typename Graph::template ANodeMap<bool> areached(*graph, false);
   355       typename Graph::template BNodeMap<bool> breached(*graph, false);
   355       typename Graph::template BNodeMap<bool> breached(*graph, false);
   356       
   356       
   357       std::vector<Node> queue;
   357       std::vector<Node> queue;
   401     /// 
   401     /// 
   402     /// Set true all matching uedge in the map. It does not change the
   402     /// Set true all matching uedge in the map. It does not change the
   403     /// value mapped to the other uedges.
   403     /// value mapped to the other uedges.
   404     /// \return The number of the matching edges.
   404     /// \return The number of the matching edges.
   405     template <typename MatchingMap>
   405     template <typename MatchingMap>
   406     int quickMatching(MatchingMap& matching) {
   406     int quickMatching(MatchingMap& matching) const {
   407       for (ANodeIt it(*graph); it != INVALID; ++it) {
   407       for (ANodeIt it(*graph); it != INVALID; ++it) {
   408         if (anode_matching[it] != INVALID) {
   408         if (anode_matching[it] != INVALID) {
   409           matching[anode_matching[it]] = true;
   409           matching[anode_matching[it]] = true;
   410         }
   410         }
   411       }
   411       }
   415     /// \brief Set true all matching uedge in the map and the others to false.
   415     /// \brief Set true all matching uedge in the map and the others to false.
   416     /// 
   416     /// 
   417     /// Set true all matching uedge in the map and the others to false.
   417     /// Set true all matching uedge in the map and the others to false.
   418     /// \return The number of the matching edges.
   418     /// \return The number of the matching edges.
   419     template <typename MatchingMap>
   419     template <typename MatchingMap>
   420     int matching(MatchingMap& matching) {
   420     int matching(MatchingMap& matching) const {
   421       for (UEdgeIt it(*graph); it != INVALID; ++it) {
   421       for (UEdgeIt it(*graph); it != INVALID; ++it) {
   422         matching[it] = it == anode_matching[graph->aNode(it)];
   422         matching[it] = it == anode_matching[graph->aNode(it)];
   423       }
   423       }
   424       return matching_size;
   424       return matching_size;
   425     }
   425     }
   426 
   426 
   427 
   427 
   428     /// \brief Return true if the given uedge is in the matching.
   428     /// \brief Return true if the given uedge is in the matching.
   429     /// 
   429     /// 
   430     /// It returns true if the given uedge is in the matching.
   430     /// It returns true if the given uedge is in the matching.
   431     bool matchingEdge(const UEdge& edge) {
   431     bool matchingEdge(const UEdge& edge) const {
   432       return anode_matching[graph->aNode(edge)] == edge;
   432       return anode_matching[graph->aNode(edge)] == edge;
   433     }
   433     }
   434 
   434 
   435     /// \brief Returns the matching edge from the node.
   435     /// \brief Returns the matching edge from the node.
   436     /// 
   436     /// 
   437     /// Returns the matching edge from the node. If there is not such
   437     /// Returns the matching edge from the node. If there is not such
   438     /// edge it gives back \c INVALID.
   438     /// edge it gives back \c INVALID.
   439     UEdge matchingEdge(const Node& node) {
   439     UEdge matchingEdge(const Node& node) const {
   440       if (graph->aNode(node)) {
   440       if (graph->aNode(node)) {
   441         return anode_matching[node];
   441         return anode_matching[node];
   442       } else {
   442       } else {
   443         return bnode_matching[node];
   443         return bnode_matching[node];
   444       }
   444       }
   460     const Graph *graph;
   460     const Graph *graph;
   461 
   461 
   462     int matching_size;
   462     int matching_size;
   463   
   463   
   464   };
   464   };
       
   465 
       
   466   /// \ingroup matching
       
   467   ///
       
   468   /// \brief Maximum cardinality bipartite matching
       
   469   ///
       
   470   /// This function calculates the maximum cardinality matching
       
   471   /// in a bipartite graph. It gives back the matching in an undirected
       
   472   /// edge map.
       
   473   ///
       
   474   /// \param graph The bipartite graph.
       
   475   /// \retval matching The undirected edge map which will be set to 
       
   476   /// the matching.
       
   477   /// \return The size of the matching.
       
   478   template <typename BpUGraph, typename MatchingMap>
       
   479   int maxBipartiteMatching(const BpUGraph& graph, MatchingMap& matching) {
       
   480     MaxBipartiteMatching<BpUGraph> bpmatching(graph);
       
   481     bpmatching.run();
       
   482     bpmatching.matching(matching);
       
   483     return bpmatching.matchingSize();
       
   484   }
   465 
   485 
   466   /// \brief Default traits class for weighted bipartite matching algoritms.
   486   /// \brief Default traits class for weighted bipartite matching algoritms.
   467   ///
   487   ///
   468   /// Default traits class for weighted bipartite matching algoritms.
   488   /// Default traits class for weighted bipartite matching algoritms.
   469   /// \param _BpUGraph The bipartite undirected graph type.
   489   /// \param _BpUGraph The bipartite undirected graph type.
   699       }
   719       }
   700       for (BNodeIt it(*graph); it != INVALID; ++it) {
   720       for (BNodeIt it(*graph); it != INVALID; ++it) {
   701         bnode_matching[it] = INVALID;
   721         bnode_matching[it] = INVALID;
   702         bnode_potential[it] = 0;
   722         bnode_potential[it] = 0;
   703         for (IncEdgeIt jt(*graph, it); jt != INVALID; ++jt) {
   723         for (IncEdgeIt jt(*graph, it); jt != INVALID; ++jt) {
   704           if (-(*weight)[jt] <= bnode_potential[it]) {
   724           if ((*weight)[jt] > bnode_potential[it]) {
   705             bnode_potential[it] = -(*weight)[jt];
   725             bnode_potential[it] = (*weight)[jt];
   706           }
   726           }
   707         }
   727         }
   708       }
   728       }
   709       matching_value = 0;
   729       matching_value = 0;
   710       matching_size = 0;
   730       matching_size = 0;
   751         Value avalue = _heap->prio();
   771         Value avalue = _heap->prio();
   752         _heap->pop();
   772         _heap->pop();
   753         for (IncEdgeIt jt(*graph, anode); jt != INVALID; ++jt) {
   773         for (IncEdgeIt jt(*graph, anode); jt != INVALID; ++jt) {
   754           if (jt == anode_matching[anode]) continue;
   774           if (jt == anode_matching[anode]) continue;
   755           Node bnode = graph->bNode(jt);
   775           Node bnode = graph->bNode(jt);
   756           Value bvalue = avalue + anode_potential[anode] - 
   776           Value bvalue = avalue  - (*weight)[jt] +
   757             bnode_potential[bnode] - (*weight)[jt];
   777             anode_potential[anode] + bnode_potential[bnode];
   758           if (bpred[bnode] == INVALID || bvalue < bdist[bnode]) {
   778           if (bpred[bnode] == INVALID || bvalue < bdist[bnode]) {
   759             bdist[bnode] = bvalue;
   779             bdist[bnode] = bvalue;
   760             bpred[bnode] = jt;
   780             bpred[bnode] = jt;
   761           }
   781           }
   762           if (bvalue > bdistMax) {
   782           if (bvalue > bdistMax) {
   776             case Heap::POST_HEAP:
   796             case Heap::POST_HEAP:
   777               break;
   797               break;
   778             }
   798             }
   779           } else {
   799           } else {
   780             if (bestNode == INVALID || 
   800             if (bestNode == INVALID || 
   781                 - bvalue - bnode_potential[bnode] > bestValue) {
   801                 bnode_potential[bnode] - bvalue > bestValue) {
   782               bestValue = - bvalue - bnode_potential[bnode];
   802               bestValue = bnode_potential[bnode] - bvalue;
   783               bestNode = bnode;
   803               bestNode = bnode;
   784             }
   804             }
   785           }
   805           }
   786         }
   806         }
   787       }
   807       }
   793       matching_value += bestValue;
   813       matching_value += bestValue;
   794       ++matching_size;
   814       ++matching_size;
   795 
   815 
   796       for (BNodeIt it(*graph); it != INVALID; ++it) {
   816       for (BNodeIt it(*graph); it != INVALID; ++it) {
   797         if (bpred[it] != INVALID) {
   817         if (bpred[it] != INVALID) {
   798           bnode_potential[it] += bdist[it];
   818           bnode_potential[it] -= bdist[it];
   799         } else {
   819         } else {
   800           bnode_potential[it] += bdistMax;
   820           bnode_potential[it] -= bdistMax;
   801         }
   821         }
   802       }
   822       }
   803       for (ANodeIt it(*graph); it != INVALID; ++it) {
   823       for (ANodeIt it(*graph); it != INVALID; ++it) {
   804         if (anode_matching[it] != INVALID) {
   824         if (anode_matching[it] != INVALID) {
   805           Node bnode = graph->bNode(anode_matching[it]);
   825           Node bnode = graph->bNode(anode_matching[it]);
   862     
   882     
   863     ///@{
   883     ///@{
   864 
   884 
   865     /// \brief Gives back the potential in the NodeMap
   885     /// \brief Gives back the potential in the NodeMap
   866     ///
   886     ///
   867     /// Gives back the potential in the NodeMap. The potential
   887     /// Gives back the potential in the NodeMap. The matching is optimal
   868     /// is feasible if \f$ \pi(a) - \pi(b) - w(ab) = 0 \f$ for
   888     /// with the current number of edges if \f$ \pi(a) + \pi(b) - w(ab) = 0 \f$
   869     /// each matching edges and \f$ \pi(a) - \pi(b) - w(ab) \ge 0 \f$
   889     /// for each matching edges and \f$ \pi(a) + \pi(b) - w(ab) \ge 0 \f$
   870     /// for each edges.
   890     /// for each edges. 
   871     template <typename PotentialMap>
   891     template <typename PotentialMap>
   872     void potential(PotentialMap& potential) {
   892     void potential(PotentialMap& potential) const {
   873       for (ANodeIt it(*graph); it != INVALID; ++it) {
   893       for (ANodeIt it(*graph); it != INVALID; ++it) {
   874         potential[it] = anode_potential[it];
   894         potential[it] = anode_potential[it];
   875       }
   895       }
   876       for (BNodeIt it(*graph); it != INVALID; ++it) {
   896       for (BNodeIt it(*graph); it != INVALID; ++it) {
   877         potential[it] = bnode_potential[it];
   897         potential[it] = bnode_potential[it];
   882     /// 
   902     /// 
   883     /// Set true all matching uedge in the map. It does not change the
   903     /// Set true all matching uedge in the map. It does not change the
   884     /// value mapped to the other uedges.
   904     /// value mapped to the other uedges.
   885     /// \return The number of the matching edges.
   905     /// \return The number of the matching edges.
   886     template <typename MatchingMap>
   906     template <typename MatchingMap>
   887     int quickMatching(MatchingMap& matching) {
   907     int quickMatching(MatchingMap& matching) const {
   888       for (ANodeIt it(*graph); it != INVALID; ++it) {
   908       for (ANodeIt it(*graph); it != INVALID; ++it) {
   889         if (anode_matching[it] != INVALID) {
   909         if (anode_matching[it] != INVALID) {
   890           matching[anode_matching[it]] = true;
   910           matching[anode_matching[it]] = true;
   891         }
   911         }
   892       }
   912       }
   896     /// \brief Set true all matching uedge in the map and the others to false.
   916     /// \brief Set true all matching uedge in the map and the others to false.
   897     /// 
   917     /// 
   898     /// Set true all matching uedge in the map and the others to false.
   918     /// Set true all matching uedge in the map and the others to false.
   899     /// \return The number of the matching edges.
   919     /// \return The number of the matching edges.
   900     template <typename MatchingMap>
   920     template <typename MatchingMap>
   901     int matching(MatchingMap& matching) {
   921     int matching(MatchingMap& matching) const {
   902       for (UEdgeIt it(*graph); it != INVALID; ++it) {
   922       for (UEdgeIt it(*graph); it != INVALID; ++it) {
   903         matching[it] = it == anode_matching[graph->aNode(it)];
   923         matching[it] = it == anode_matching[graph->aNode(it)];
   904       }
   924       }
   905       return matching_size;
   925       return matching_size;
   906     }
   926     }
   907 
   927 
   908 
   928 
   909     /// \brief Return true if the given uedge is in the matching.
   929     /// \brief Return true if the given uedge is in the matching.
   910     /// 
   930     /// 
   911     /// It returns true if the given uedge is in the matching.
   931     /// It returns true if the given uedge is in the matching.
   912     bool matchingEdge(const UEdge& edge) {
   932     bool matchingEdge(const UEdge& edge) const {
   913       return anode_matching[graph->aNode(edge)] == edge;
   933       return anode_matching[graph->aNode(edge)] == edge;
   914     }
   934     }
   915 
   935 
   916     /// \brief Returns the matching edge from the node.
   936     /// \brief Returns the matching edge from the node.
   917     /// 
   937     /// 
   918     /// Returns the matching edge from the node. If there is not such
   938     /// Returns the matching edge from the node. If there is not such
   919     /// edge it gives back \c INVALID.
   939     /// edge it gives back \c INVALID.
   920     UEdge matchingEdge(const Node& node) {
   940     UEdge matchingEdge(const Node& node) const {
   921       if (graph->aNode(node)) {
   941       if (graph->aNode(node)) {
   922         return anode_matching[node];
   942         return anode_matching[node];
   923       } else {
   943       } else {
   924         return bnode_matching[node];
   944         return bnode_matching[node];
   925       }
   945       }
   979 
   999 
   980     Heap *_heap;
  1000     Heap *_heap;
   981     bool local_heap;
  1001     bool local_heap;
   982   
  1002   
   983   };
  1003   };
       
  1004 
       
  1005   /// \ingroup matching
       
  1006   ///
       
  1007   /// \brief Maximum weighted bipartite matching
       
  1008   ///
       
  1009   /// This function calculates the maximum weighted matching
       
  1010   /// in a bipartite graph. It gives back the matching in an undirected
       
  1011   /// edge map.
       
  1012   ///
       
  1013   /// \param graph The bipartite graph.
       
  1014   /// \param weight The undirected edge map which contains the weights.
       
  1015   /// \retval matching The undirected edge map which will be set to 
       
  1016   /// the matching.
       
  1017   /// \return The value of the matching.
       
  1018   template <typename BpUGraph, typename WeightMap, typename MatchingMap>
       
  1019   typename WeightMap::Value 
       
  1020   maxWeightedBipartiteMatching(const BpUGraph& graph, const WeightMap& weight,
       
  1021                                MatchingMap& matching) {
       
  1022     MaxWeightedBipartiteMatching<BpUGraph, WeightMap> 
       
  1023       bpmatching(graph, weight);
       
  1024     bpmatching.run();
       
  1025     bpmatching.matching(matching);
       
  1026     return bpmatching.matchingValue();
       
  1027   }
       
  1028 
       
  1029   /// \ingroup matching
       
  1030   ///
       
  1031   /// \brief Maximum weighted maximum cardinality bipartite matching
       
  1032   ///
       
  1033   /// This function calculates the maximum weighted of the maximum cardinality
       
  1034   /// matchings of a bipartite graph. It gives back the matching in an 
       
  1035   /// undirected edge map.
       
  1036   ///
       
  1037   /// \param graph The bipartite graph.
       
  1038   /// \param weight The undirected edge map which contains the weights.
       
  1039   /// \retval matching The undirected edge map which will be set to 
       
  1040   /// the matching.
       
  1041   /// \return The value of the matching.
       
  1042   template <typename BpUGraph, typename WeightMap, typename MatchingMap>
       
  1043   typename WeightMap::Value 
       
  1044   maxWeightedMaxBipartiteMatching(const BpUGraph& graph, 
       
  1045                                   const WeightMap& weight,
       
  1046                                   MatchingMap& matching) {
       
  1047     MaxWeightedBipartiteMatching<BpUGraph, WeightMap> 
       
  1048       bpmatching(graph, weight);
       
  1049     bpmatching.run(true);
       
  1050     bpmatching.matching(matching);
       
  1051     return bpmatching.matchingValue();
       
  1052   }
   984 
  1053 
   985   /// \brief Default traits class for minimum cost bipartite matching
  1054   /// \brief Default traits class for minimum cost bipartite matching
   986   /// algoritms.
  1055   /// algoritms.
   987   ///
  1056   ///
   988   /// Default traits class for minimum cost bipartite matching
  1057   /// Default traits class for minimum cost bipartite matching
  1358     
  1427     
  1359     ///@{
  1428     ///@{
  1360 
  1429 
  1361     /// \brief Gives back the potential in the NodeMap
  1430     /// \brief Gives back the potential in the NodeMap
  1362     ///
  1431     ///
  1363     /// Gives back the potential in the NodeMap. The potential
  1432     /// Gives back the potential in the NodeMap. The potential is optimal with 
  1364     /// is feasible if \f$ \pi(a) - \pi(b) + w(ab) = 0 \f$ for
  1433     /// the current number of edges if \f$ \pi(a) - \pi(b) + w(ab) = 0 \f$ for
  1365     /// each matching edges and \f$ \pi(a) - \pi(b) + w(ab) \ge 0 \f$
  1434     /// each matching edges and \f$ \pi(a) - \pi(b) + w(ab) \ge 0 \f$
  1366     /// for each edges.
  1435     /// for each edges.
  1367     template <typename PotentialMap>
  1436     template <typename PotentialMap>
  1368     void potential(PotentialMap& potential) {
  1437     void potential(PotentialMap& potential) const {
  1369       for (ANodeIt it(*graph); it != INVALID; ++it) {
  1438       for (ANodeIt it(*graph); it != INVALID; ++it) {
  1370         potential[it] = anode_potential[it];
  1439         potential[it] = anode_potential[it];
  1371       }
  1440       }
  1372       for (BNodeIt it(*graph); it != INVALID; ++it) {
  1441       for (BNodeIt it(*graph); it != INVALID; ++it) {
  1373         potential[it] = bnode_potential[it];
  1442         potential[it] = bnode_potential[it];
  1378     /// 
  1447     /// 
  1379     /// Set true all matching uedge in the map. It does not change the
  1448     /// Set true all matching uedge in the map. It does not change the
  1380     /// value mapped to the other uedges.
  1449     /// value mapped to the other uedges.
  1381     /// \return The number of the matching edges.
  1450     /// \return The number of the matching edges.
  1382     template <typename MatchingMap>
  1451     template <typename MatchingMap>
  1383     int quickMatching(MatchingMap& matching) {
  1452     int quickMatching(MatchingMap& matching) const {
  1384       for (ANodeIt it(*graph); it != INVALID; ++it) {
  1453       for (ANodeIt it(*graph); it != INVALID; ++it) {
  1385         if (anode_matching[it] != INVALID) {
  1454         if (anode_matching[it] != INVALID) {
  1386           matching[anode_matching[it]] = true;
  1455           matching[anode_matching[it]] = true;
  1387         }
  1456         }
  1388       }
  1457       }
  1392     /// \brief Set true all matching uedge in the map and the others to false.
  1461     /// \brief Set true all matching uedge in the map and the others to false.
  1393     /// 
  1462     /// 
  1394     /// Set true all matching uedge in the map and the others to false.
  1463     /// Set true all matching uedge in the map and the others to false.
  1395     /// \return The number of the matching edges.
  1464     /// \return The number of the matching edges.
  1396     template <typename MatchingMap>
  1465     template <typename MatchingMap>
  1397     int matching(MatchingMap& matching) {
  1466     int matching(MatchingMap& matching) const {
  1398       for (UEdgeIt it(*graph); it != INVALID; ++it) {
  1467       for (UEdgeIt it(*graph); it != INVALID; ++it) {
  1399         matching[it] = it == anode_matching[graph->aNode(it)];
  1468         matching[it] = it == anode_matching[graph->aNode(it)];
  1400       }
  1469       }
  1401       return matching_size;
  1470       return matching_size;
  1402     }
  1471     }
  1403 
  1472 
  1404 
  1473 
  1405     /// \brief Return true if the given uedge is in the matching.
  1474     /// \brief Return true if the given uedge is in the matching.
  1406     /// 
  1475     /// 
  1407     /// It returns true if the given uedge is in the matching.
  1476     /// It returns true if the given uedge is in the matching.
  1408     bool matchingEdge(const UEdge& edge) {
  1477     bool matchingEdge(const UEdge& edge) const {
  1409       return anode_matching[graph->aNode(edge)] == edge;
  1478       return anode_matching[graph->aNode(edge)] == edge;
  1410     }
  1479     }
  1411 
  1480 
  1412     /// \brief Returns the matching edge from the node.
  1481     /// \brief Returns the matching edge from the node.
  1413     /// 
  1482     /// 
  1414     /// Returns the matching edge from the node. If there is not such
  1483     /// Returns the matching edge from the node. If there is not such
  1415     /// edge it gives back \c INVALID.
  1484     /// edge it gives back \c INVALID.
  1416     UEdge matchingEdge(const Node& node) {
  1485     UEdge matchingEdge(const Node& node) const {
  1417       if (graph->aNode(node)) {
  1486       if (graph->aNode(node)) {
  1418         return anode_matching[node];
  1487         return anode_matching[node];
  1419       } else {
  1488       } else {
  1420         return bnode_matching[node];
  1489         return bnode_matching[node];
  1421       }
  1490       }
  1476     Heap *_heap;
  1545     Heap *_heap;
  1477     bool local_heap;
  1546     bool local_heap;
  1478   
  1547   
  1479   };
  1548   };
  1480 
  1549 
       
  1550   /// \ingroup matching
       
  1551   ///
       
  1552   /// \brief Minimum cost maximum cardinality bipartite matching
       
  1553   ///
       
  1554   /// This function calculates the minimum cost matching of the maximum 
       
  1555   /// cardinality matchings of a bipartite graph. It gives back the matching 
       
  1556   /// in an undirected edge map.
       
  1557   ///
       
  1558   /// \param graph The bipartite graph.
       
  1559   /// \param cost The undirected edge map which contains the costs.
       
  1560   /// \retval matching The undirected edge map which will be set to 
       
  1561   /// the matching.
       
  1562   /// \return The cost of the matching.
       
  1563   template <typename BpUGraph, typename CostMap, typename MatchingMap>
       
  1564   typename CostMap::Value 
       
  1565   minCostMaxBipartiteMatching(const BpUGraph& graph, 
       
  1566                               const CostMap& cost,
       
  1567                               MatchingMap& matching) {
       
  1568     MinCostMaxBipartiteMatching<BpUGraph, CostMap> 
       
  1569       bpmatching(graph, cost);
       
  1570     bpmatching.run();
       
  1571     bpmatching.matching(matching);
       
  1572     return bpmatching.matchingCost();
       
  1573   }
       
  1574 
  1481 }
  1575 }
  1482 
  1576 
  1483 #endif
  1577 #endif