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@@ -444,52 +444,55 @@ |
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- \ref HaoOrlin "Hao-Orlin algorithm" for calculating minimum cut |
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in directed graphs. |
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- \ref NagamochiIbaraki "Nagamochi-Ibaraki algorithm" for |
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calculating minimum cut in undirected graphs. |
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- \ref GomoryHu "Gomory-Hu tree computation" for calculating |
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all-pairs minimum cut in undirected graphs. |
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|
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If you want to find minimum cut just between two distinict nodes, |
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see the \ref max_flow "maximum flow problem". |
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*/ |
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|
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/** |
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@defgroup min_mean_cycle Minimum Mean Cycle Algorithms |
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@ingroup algs |
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\brief Algorithms for finding minimum mean cycles. |
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|
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This group contains the algorithms for finding minimum mean cycles |
|
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This group contains the algorithms for finding minimum mean cycles |
|
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\ref clrs01algorithms, \ref amo93networkflows. |
|
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|
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The \e minimum \e mean \e cycle \e problem is to find a directed cycle |
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of minimum mean length (cost) in a digraph. |
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The mean length of a cycle is the average length of its arcs, i.e. the |
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ratio between the total length of the cycle and the number of arcs on it. |
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|
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This problem has an important connection to \e conservative \e length |
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\e functions, too. A length function on the arcs of a digraph is called |
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conservative if and only if there is no directed cycle of negative total |
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length. For an arbitrary length function, the negative of the minimum |
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cycle mean is the smallest \f$\epsilon\f$ value so that increasing the |
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arc lengths uniformly by \f$\epsilon\f$ results in a conservative length |
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function. |
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|
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LEMON contains three algorithms for solving the minimum mean cycle problem: |
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- \ref Karp "Karp"'s original algorithm |
|
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- \ref Karp "Karp"'s original algorithm \ref amo93networkflows, |
|
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\ref dasdan98minmeancycle. |
|
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- \ref HartmannOrlin "Hartmann-Orlin"'s algorithm, which is an improved |
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version of Karp's algorithm. |
|
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- \ref Howard "Howard"'s policy iteration algorithm. |
|
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version of Karp's algorithm \ref dasdan98minmeancycle. |
|
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- \ref Howard "Howard"'s policy iteration algorithm |
|
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\ref dasdan98minmeancycle. |
|
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|
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In practice, the Howard algorithm proved to be by far the most efficient |
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one, though the best known theoretical bound on its running time is |
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exponential. |
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Both Karp and HartmannOrlin algorithms run in time O(ne) and use space |
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O(n<sup>2</sup>+e), but the latter one is typically faster due to the |
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applied early termination scheme. |
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*/ |
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|
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/** |
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@defgroup matching Matching Algorithms |
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@ingroup algs |
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\brief Algorithms for finding matchings in graphs and bipartite graphs. |
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|
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This group contains the algorithms for calculating |
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matchings in graphs and bipartite graphs. The general matching problem is |
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@@ -84,33 +84,34 @@ |
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typedef long long LargeValue; |
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#else |
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typedef long LargeValue; |
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#endif |
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typedef lemon::Tolerance<LargeValue> Tolerance; |
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typedef lemon::Path<Digraph> Path; |
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}; |
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|
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|
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/// \addtogroup min_mean_cycle |
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/// @{ |
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|
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/// \brief Implementation of the Hartmann-Orlin algorithm for finding |
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/// a minimum mean cycle. |
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/// |
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/// This class implements the Hartmann-Orlin algorithm for finding |
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/// a directed cycle of minimum mean length (cost) in a digraph |
|
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/// a directed cycle of minimum mean length (cost) in a digraph |
|
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/// \ref amo93networkflows, \ref dasdan98minmeancycle. |
|
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/// It is an improved version of \ref Karp "Karp"'s original algorithm, |
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/// it applies an efficient early termination scheme. |
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/// It runs in time O(ne) and uses space O(n<sup>2</sup>+e). |
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/// |
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/// \tparam GR The type of the digraph the algorithm runs on. |
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/// \tparam LEN The type of the length map. The default |
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/// map type is \ref concepts::Digraph::ArcMap "GR::ArcMap<int>". |
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#ifdef DOXYGEN |
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template <typename GR, typename LEN, typename TR> |
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#else |
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template < typename GR, |
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typename LEN = typename GR::template ArcMap<int>, |
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typename TR = HartmannOrlinDefaultTraits<GR, LEN> > |
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#endif |
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class HartmannOrlin |
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{ |
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@@ -84,33 +84,34 @@ |
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typedef long long LargeValue; |
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#else |
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typedef long LargeValue; |
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#endif |
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typedef lemon::Tolerance<LargeValue> Tolerance; |
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typedef lemon::Path<Digraph> Path; |
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}; |
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|
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|
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/// \addtogroup min_mean_cycle |
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/// @{ |
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|
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/// \brief Implementation of Howard's algorithm for finding a minimum |
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/// mean cycle. |
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/// |
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/// This class implements Howard's policy iteration algorithm for finding |
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/// a directed cycle of minimum mean length (cost) in a digraph |
|
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/// a directed cycle of minimum mean length (cost) in a digraph |
|
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/// \ref amo93networkflows, \ref dasdan98minmeancycle. |
|
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/// This class provides the most efficient algorithm for the |
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/// minimum mean cycle problem, though the best known theoretical |
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/// bound on its running time is exponential. |
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/// |
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/// \tparam GR The type of the digraph the algorithm runs on. |
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/// \tparam LEN The type of the length map. The default |
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/// map type is \ref concepts::Digraph::ArcMap "GR::ArcMap<int>". |
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#ifdef DOXYGEN |
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template <typename GR, typename LEN, typename TR> |
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#else |
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template < typename GR, |
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typename LEN = typename GR::template ArcMap<int>, |
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typename TR = HowardDefaultTraits<GR, LEN> > |
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#endif |
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class Howard |
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{ |
... | ... |
@@ -84,33 +84,34 @@ |
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typedef long long LargeValue; |
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#else |
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typedef long LargeValue; |
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#endif |
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typedef lemon::Tolerance<LargeValue> Tolerance; |
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typedef lemon::Path<Digraph> Path; |
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}; |
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|
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|
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/// \addtogroup min_mean_cycle |
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/// @{ |
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|
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/// \brief Implementation of Karp's algorithm for finding a minimum |
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/// mean cycle. |
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/// |
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/// This class implements Karp's algorithm for finding a directed |
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/// cycle of minimum mean length (cost) in a digraph |
|
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/// cycle of minimum mean length (cost) in a digraph |
|
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/// \ref amo93networkflows, \ref dasdan98minmeancycle. |
|
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/// It runs in time O(ne) and uses space O(n<sup>2</sup>+e). |
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/// |
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/// \tparam GR The type of the digraph the algorithm runs on. |
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/// \tparam LEN The type of the length map. The default |
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/// map type is \ref concepts::Digraph::ArcMap "GR::ArcMap<int>". |
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#ifdef DOXYGEN |
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template <typename GR, typename LEN, typename TR> |
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#else |
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template < typename GR, |
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typename LEN = typename GR::template ArcMap<int>, |
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typename TR = KarpDefaultTraits<GR, LEN> > |
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#endif |
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class Karp |
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{ |
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public: |
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|
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