RhodeCode

/* -*- C++ -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2003-2008

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

#ifndef LEMON_KRUSKAL_H

#define LEMON_KRUSKAL_H

#include <algorithm>

#include <vector>

#include <lemon/unionfind.h>

// #include <lemon/graph_utils.h>

#include <lemon/maps.h>

// #include <lemon/radix_sort.h>

#include <lemon/bits/utility.h>

#include <lemon/bits/traits.h>

///\ingroup spantree

///\file

///\brief Kruskal's algorithm to compute a minimum cost tree

///

///Kruskal's algorithm to compute a minimum cost tree.

///

namespace lemon {

  namespace _kruskal_bits {

    // Kruskal for directed graphs.

    template <typename Digraph, typename In, typename Out>

    typename disable_if<lemon::UndirectedTagIndicator<Digraph>,

		       typename In::value_type::second_type >::type

    kruskal(const Digraph& digraph, const In& in, Out& out,dummy<0> = 0) {

      typedef typename In::value_type::second_type Value;

      typedef typename Digraph::template NodeMap<int> IndexMap;

      typedef typename Digraph::Node Node;

      IndexMap index(digraph);

      UnionFind<IndexMap> uf(index);

      for (typename Digraph::NodeIt it(digraph); it != INVALID; ++it) {

        uf.insert(it);

      }

      Value tree_value = 0;

      for (typename In::const_iterator it = in.begin(); it != in.end(); ++it) {

        if (uf.join(digraph.target(it->first),digraph.source(it->first))) {

          out.set(it->first, true);

          tree_value += it->second;

        }

        else {

          out.set(it->first, false);

        }

      }

      return tree_value;

    }

    // Kruskal for undirected graphs.

    template <typename Graph, typename In, typename Out>

    typename enable_if<lemon::UndirectedTagIndicator<Graph>,

		       typename In::value_type::second_type >::type

    kruskal(const Graph& graph, const In& in, Out& out,dummy<1> = 1) {

      typedef typename In::value_type::second_type Value;

      typedef typename Graph::template NodeMap<int> IndexMap;

      typedef typename Graph::Node Node;

      IndexMap index(graph);

      UnionFind<IndexMap> uf(index);

      for (typename Graph::NodeIt it(graph); it != INVALID; ++it) {

        uf.insert(it);

      }

      Value tree_value = 0;

      for (typename In::const_iterator it = in.begin(); it != in.end(); ++it) {

        if (uf.join(graph.u(it->first),graph.v(it->first))) {

          out.set(it->first, true);

          tree_value += it->second;

        }

        else {

          out.set(it->first, false);

        }

      }

      return tree_value;

    }

    template <typename Sequence>

    struct PairComp {

      typedef typename Sequence::value_type Value;

      bool operator()(const Value& left, const Value& right) {

	return left.second < right.second;

      }

    };

    template <typename In, typename Enable = void>

    struct SequenceInputIndicator {

      static const bool value = false;

    };

    template <typename In>

    struct SequenceInputIndicator<In, 

      typename exists<typename In::value_type::first_type>::type> {

      static const bool value = true;

    };

    template <typename In, typename Enable = void>

    struct MapInputIndicator {

      static const bool value = false;

    };

    template <typename In>

    struct MapInputIndicator<In, 

      typename exists<typename In::Value>::type> {

      static const bool value = true;

    };

    template <typename In, typename Enable = void>

    struct SequenceOutputIndicator {

      static const bool value = false;

    };

    template <typename Out>

    struct SequenceOutputIndicator<Out, 

      typename exists<typename Out::value_type>::type> {

      static const bool value = true;

    };

    template <typename Out, typename Enable = void>

    struct MapOutputIndicator {

      static const bool value = false;

    };

    template <typename Out>

    struct MapOutputIndicator<Out, 

      typename exists<typename Out::Value>::type> {

      static const bool value = true;

    };

    template <typename In, typename InEnable = void>

    struct KruskalValueSelector {};

    template <typename In>

    struct KruskalValueSelector<In,

      typename enable_if<SequenceInputIndicator<In>, void>::type> 

    {

      typedef typename In::value_type::second_type Value;

    };    

    template <typename In>

    struct KruskalValueSelector<In,

      typename enable_if<MapInputIndicator<In>, void>::type> 

    {

      typedef typename In::Value Value;

    };    

    template <typename Graph, typename In, typename Out,

              typename InEnable = void>

    struct KruskalInputSelector {};

    template <typename Graph, typename In, typename Out,

              typename InEnable = void>

    struct KruskalOutputSelector {};

    template <typename Graph, typename In, typename Out>

    struct KruskalInputSelector<Graph, In, Out,

      typename enable_if<SequenceInputIndicator<In>, void>::type > 

    {

      typedef typename In::value_type::second_type Value;

      static Value kruskal(const Graph& graph, const In& in, Out& out) {

        return KruskalOutputSelector<Graph, In, Out>::

          kruskal(graph, in, out);

      }

    };

    template <typename Graph, typename In, typename Out>

    struct KruskalInputSelector<Graph, In, Out,

      typename enable_if<MapInputIndicator<In>, void>::type > 

    {

      typedef typename In::Value Value;

      static Value kruskal(const Graph& graph, const In& in, Out& out) {

        typedef typename In::Key MapArc;

        typedef typename In::Value Value;

        typedef typename ItemSetTraits<Graph, MapArc>::ItemIt MapArcIt;

        typedef std::vector<std::pair<MapArc, Value> > Sequence;

        Sequence seq;

        for (MapArcIt it(graph); it != INVALID; ++it) {

          seq.push_back(std::make_pair(it, in[it]));

        }

        std::sort(seq.begin(), seq.end(), PairComp<Sequence>());

        return KruskalOutputSelector<Graph, Sequence, Out>::

          kruskal(graph, seq, out);

      }

    };

    template <typename Graph, typename In, typename Out>

    struct KruskalOutputSelector<Graph, In, Out,

      typename enable_if<SequenceOutputIndicator<Out>, void>::type > 

    {

      typedef typename In::value_type::second_type Value;

      static Value kruskal(const Graph& graph, const In& in, Out& out) {

        Map map(out);

        return _kruskal_bits::kruskal(graph, in, map);

      }

    };

    template <typename Graph, typename In, typename Out>

    struct KruskalOutputSelector<Graph, In, Out,

      typename enable_if<MapOutputIndicator<Out>, void>::type > 

    {

      typedef typename In::value_type::second_type Value;

      static Value kruskal(const Graph& graph, const In& in, Out& out) {

        return _kruskal_bits::kruskal(graph, in, out);

      }

    };

  }

  /// \ingroup spantree

  ///

  /// \brief Kruskal's algorithm to find a minimum cost tree of a graph.

  ///

  /// This function runs Kruskal's algorithm to find a minimum cost tree.

  /// Due to some C++ hacking, it accepts various input and output types.

  ///

  /// \param g The graph the algorithm runs on.

  /// It can be either \ref concepts::Digraph "directed" or 

  /// \ref concepts::Graph "undirected".

  /// If the graph is directed, the algorithm consider it to be 

  /// undirected by disregarding the direction of the arcs.

  ///

  /// \param in This object is used to describe the arc costs. It can be one

  /// of the following choices.

  /// - An STL compatible 'Forward Container' with

  /// <tt>std::pair<GR::Edge,X></tt> or

  /// <tt>std::pair<GR::Arc,X></tt> as its <tt>value_type</tt>, where

  /// \c X is the type of the costs. The pairs indicates the arcs

  /// along with the assigned cost. <em>They must be in a

  /// cost-ascending order.</em>

  /// - Any readable Arc map. The values of the map indicate the arc costs.

  ///

  /// \retval out Here we also have a choise.

  /// - It can be a writable \c bool arc map.  After running the

  /// algorithm this will contain the found minimum cost spanning

  /// tree: the value of an arc will be set to \c true if it belongs

  /// to the tree, otherwise it will be set to \c false. The value of

  /// each arc will be set exactly once.

  /// - It can also be an iteraror of an STL Container with

  /// <tt>GR::Edge</tt> or <tt>GR::Arc</tt> as its

  /// <tt>value_type</tt>.  The algorithm copies the elements of the

  /// found tree into this sequence.  For example, if we know that the

  /// spanning tree of the graph \c g has say 53 arcs, then we can

  /// put its arcs into an STL vector \c tree with a code like this.

  ///\code

  /// std::vector<Arc> tree(53);

  /// kruskal(g,cost,tree.begin());

  ///\endcode

  /// Or if we don't know in advance the size of the tree, we can

  /// write this.  

  ///\code std::vector<Arc> tree;

  /// kruskal(g,cost,std::back_inserter(tree)); 

  ///\endcode

  ///

  /// \return The total cost of the found tree.

  ///

  /// \warning If kruskal runs on an be consistent of using the same

  /// Arc type for input and output.

  ///

#ifdef DOXYGEN

  template <class Graph, class In, class Out>

  Value kruskal(GR const& g, const In& in, Out& out)

#else 

  template <class Graph, class In, class Out>

  inline typename _kruskal_bits::KruskalValueSelector<In>::Value 

  kruskal(const Graph& graph, const In& in, Out& out) 

#endif

  {

    return _kruskal_bits::KruskalInputSelector<Graph, In, Out>::

      kruskal(graph, in, out);

  }

  template <class Graph, class In, class Out>

  inline typename _kruskal_bits::KruskalValueSelector<In>::Value

  kruskal(const Graph& graph, const In& in, const Out& out)

  {

    return _kruskal_bits::KruskalInputSelector<Graph, In, const Out>::

      kruskal(graph, in, out);

  }  

} //namespace lemon

#endif //LEMON_KRUSKAL_H

/* -*- C++ -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2003-2008

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

#include <deque>

#include <set>

#include <lemon/concept_check.h>

#include <lemon/concepts/maps.h>

#include <lemon/maps.h>

#include "test_tools.h"

using namespace lemon;

using namespace lemon::concepts;

struct A {};

inline bool operator<(A, A) { return true; }

struct B {};

class C {

  int x;

public:

  C(int _x) : x(_x) {}

};

class F {

public:

  typedef A argument_type;

  typedef B result_type;

  B operator()(const A&) const { return B(); }

private:

  F& operator=(const F&);

};

int func(A) { return 3; }

int binc(int a, B) { return a+1; }

typedef ReadMap<A, double> DoubleMap;

typedef ReadWriteMap<A, double> DoubleWriteMap;

typedef ReferenceMap<A, double, double&, const double&> DoubleRefMap;

typedef ReadMap<A, bool> BoolMap;

typedef ReadWriteMap<A, bool> BoolWriteMap;

typedef ReferenceMap<A, bool, bool&, const bool&> BoolRefMap;

int main()

{

  // Map concepts

  checkConcept<ReadMap<A,B>, ReadMap<A,B> >();

  checkConcept<ReadMap<A,C>, ReadMap<A,C> >();

  checkConcept<WriteMap<A,B>, WriteMap<A,B> >();

  checkConcept<WriteMap<A,C>, WriteMap<A,C> >();

  checkConcept<ReadWriteMap<A,B>, ReadWriteMap<A,B> >();

  checkConcept<ReadWriteMap<A,C>, ReadWriteMap<A,C> >();

  checkConcept<ReferenceMap<A,B,B&,const B&>, ReferenceMap<A,B,B&,const B&> >();

  checkConcept<ReferenceMap<A,C,C&,const C&>, ReferenceMap<A,C,C&,const C&> >();

  // NullMap

  {

    checkConcept<ReadWriteMap<A,B>, NullMap<A,B> >();

    NullMap<A,B> map1;

    NullMap<A,B> map2 = map1;

    map1 = nullMap<A,B>();

  }

  // ConstMap

  {

    checkConcept<ReadWriteMap<A,B>, ConstMap<A,B> >();

    checkConcept<ReadWriteMap<A,C>, ConstMap<A,C> >();

    ConstMap<A,B> map1;

    ConstMap<A,B> map3 = map1;

    map1 = constMap<A>(B());

    map1 = constMap<A,B>();

    map1.setAll(B());

    ConstMap<A,C> map4(C(1));

    ConstMap<A,C> map5 = map4;

    map4 = constMap<A>(C(2));

    map4.setAll(C(3));

    checkConcept<ReadWriteMap<A,int>, ConstMap<A,int> >();

    check(constMap<A>(10)[A()] == 10, "Something is wrong with ConstMap");

    checkConcept<ReadWriteMap<A,int>, ConstMap<A,Const<int,10> > >();

    ConstMap<A,Const<int,10> > map6;

    ConstMap<A,Const<int,10> > map7 = map6;

    map6 = constMap<A,int,10>();

    map7 = constMap<A,Const<int,10> >();

    check(map6[A()] == 10 && map7[A()] == 10, "Something is wrong with ConstMap");

  }

  // IdentityMap

  {

    checkConcept<ReadMap<A,A>, IdentityMap<A> >();

    IdentityMap<A> map1;

    IdentityMap<A> map2 = map1;

    map1 = identityMap<A>();

    checkConcept<ReadMap<double,double>, IdentityMap<double> >();

    check(identityMap<double>()[1.0] == 1.0 && identityMap<double>()[3.14] == 3.14,

          "Something is wrong with IdentityMap");

  }

  // RangeMap

  {

    checkConcept<ReferenceMap<int,B,B&,const B&>, RangeMap<B> >();

    RangeMap<B> map1;

    RangeMap<B> map2(10);

    RangeMap<B> map3(10,B());

    RangeMap<B> map4 = map1;

    RangeMap<B> map5 = rangeMap<B>();

    RangeMap<B> map6 = rangeMap<B>(10);

    RangeMap<B> map7 = rangeMap(10,B());

    checkConcept< ReferenceMap<int, double, double&, const double&>,

                  RangeMap<double> >();

    std::vector<double> v(10, 0);

    v[5] = 100;

    RangeMap<double> map8(v);

    RangeMap<double> map9 = rangeMap(v);

    check(map9.size() == 10 && map9[2] == 0 && map9[5] == 100,

          "Something is wrong with RangeMap");

  }

  // SparseMap

  {

    checkConcept<ReferenceMap<A,B,B&,const B&>, SparseMap<A,B> >();

    SparseMap<A,B> map1;

    SparseMap<A,B> map3 = sparseMap<A,B>();

    SparseMap<A,B> map4 = sparseMap<A>(B());

    checkConcept< ReferenceMap<double, int, int&, const int&>,

                  SparseMap<double, int> >();

    std::map<double, int> m;

    SparseMap<double, int> map5(m);

    SparseMap<double, int> map6(m,10);

    SparseMap<double, int> map7 = sparseMap(m);

    SparseMap<double, int> map8 = sparseMap(m,10);

    check(map5[1.0] == 0 && map5[3.14] == 0 && map6[1.0] == 10 && map6[3.14] == 10,

          "Something is wrong with SparseMap");

    map5[1.0] = map6[3.14] = 100;

    check(map5[1.0] == 100 && map5[3.14] == 0 && map6[1.0] == 10 && map6[3.14] == 100,

          "Something is wrong with SparseMap");

  }

  // ComposeMap

  {

    typedef ComposeMap<DoubleMap, ReadMap<B,A> > CompMap;

    checkConcept<ReadMap<B,double>, CompMap>();

    CompMap map1(DoubleMap(),ReadMap<B,A>());

    CompMap map2 = composeMap(DoubleMap(), ReadMap<B,A>());

    SparseMap<double, bool> m1(false); m1[3.14] = true;

    RangeMap<double> m2(2); m2[0] = 3.0; m2[1] = 3.14;

    check(!composeMap(m1,m2)[0] && composeMap(m1,m2)[1], "Something is wrong with ComposeMap")

  }

  // CombineMap

  {

    typedef CombineMap<DoubleMap, DoubleMap, std::plus<double> > CombMap;

    checkConcept<ReadMap<A,double>, CombMap>();

    CombMap map1(DoubleMap(), DoubleMap());

    CombMap map2 = combineMap(DoubleMap(), DoubleMap(), std::plus<double>());

    check(combineMap(constMap<B,int,2>(), identityMap<B>(), &binc)[B()] == 3,

          "Something is wrong with CombineMap");

  }

  // FunctorToMap, MapToFunctor

  {

    checkConcept<ReadMap<A,B>, FunctorToMap<F,A,B> >();

    checkConcept<ReadMap<A,B>, FunctorToMap<F> >();

    FunctorToMap<F> map1;

    FunctorToMap<F> map2(F());

    B b = functorToMap(F())[A()];

    checkConcept<ReadMap<A,B>, MapToFunctor<ReadMap<A,B> > >();

    MapToFunctor<ReadMap<A,B> > map(ReadMap<A,B>());

    check(functorToMap(&func)[A()] == 3, "Something is wrong with FunctorToMap");

    check(mapToFunctor(constMap<A,int>(2))(A()) == 2, "Something is wrong with MapToFunctor");

    check(mapToFunctor(functorToMap(&func))(A()) == 3 && mapToFunctor(functorToMap(&func))[A()] == 3,

          "Something is wrong with FunctorToMap or MapToFunctor");

    check(functorToMap(mapToFunctor(constMap<A,int>(2)))[A()] == 2,

          "Something is wrong with FunctorToMap or MapToFunctor");

  }

  // ConvertMap

  {

    checkConcept<ReadMap<double,double>, ConvertMap<ReadMap<double, int>, double> >();

    ConvertMap<RangeMap<bool>, int> map1(rangeMap(1, true));

    ConvertMap<RangeMap<bool>, int> map2 = convertMap<int>(rangeMap(2, false));

  }

  // ForkMap

  {

    checkConcept<DoubleWriteMap, ForkMap<DoubleWriteMap, DoubleWriteMap> >();

    typedef RangeMap<double> RM;

    typedef SparseMap<int, double> SM;

    RM m1(10, -1);

    SM m2(-1);

    checkConcept<ReadWriteMap<int, double>, ForkMap<RM, SM> >();

    checkConcept<ReadWriteMap<int, double>, ForkMap<SM, RM> >();

    ForkMap<RM, SM> map1(m1,m2);

    ForkMap<SM, RM> map2 = forkMap(m2,m1);

    map2.set(5, 10);

    check(m1[1] == -1 && m1[5] == 10 && m2[1] == -1 && m2[5] == 10 && map2[1] == -1 && map2[5] == 10,

          "Something is wrong with ForkMap");

  }

  // Arithmetic maps:

  // - AddMap, SubMap, MulMap, DivMap

  // - ShiftMap, ShiftWriteMap, ScaleMap, ScaleWriteMap

  // - NegMap, NegWriteMap, AbsMap

  {

    checkConcept<DoubleMap, AddMap<DoubleMap,DoubleMap> >();

    checkConcept<DoubleMap, SubMap<DoubleMap,DoubleMap> >();

    checkConcept<DoubleMap, MulMap<DoubleMap,DoubleMap> >();

    checkConcept<DoubleMap, DivMap<DoubleMap,DoubleMap> >();

    ConstMap<int, double> c1(1.0), c2(3.14);

    IdentityMap<int> im;

    ConvertMap<IdentityMap<int>, double> id(im);

    check(addMap(c1,id)[0] == 1.0  && addMap(c1,id)[10] == 11.0, "Something is wrong with AddMap");

    check(subMap(id,c1)[0] == -1.0 && subMap(id,c1)[10] == 9.0,  "Something is wrong with SubMap");

    check(mulMap(id,c2)[0] == 0    && mulMap(id,c2)[2]  == 6.28, "Something is wrong with MulMap");

    check(divMap(c2,id)[1] == 3.14 && divMap(c2,id)[2]  == 1.57, "Something is wrong with DivMap");

    checkConcept<DoubleMap, ShiftMap<DoubleMap> >();

    checkConcept<DoubleWriteMap, ShiftWriteMap<DoubleWriteMap> >();

    checkConcept<DoubleMap, ScaleMap<DoubleMap> >();

    checkConcept<DoubleWriteMap, ScaleWriteMap<DoubleWriteMap> >();

    checkConcept<DoubleMap, NegMap<DoubleMap> >();

    checkConcept<DoubleWriteMap, NegWriteMap<DoubleWriteMap> >();

    checkConcept<DoubleMap, AbsMap<DoubleMap> >();

    check(shiftMap(id, 2.0)[1] == 3.0 && shiftMap(id, 2.0)[10] == 12.0,

          "Something is wrong with ShiftMap");

    check(shiftWriteMap(id, 2.0)[1] == 3.0 && shiftWriteMap(id, 2.0)[10] == 12.0,

          "Something is wrong with ShiftWriteMap");

    check(scaleMap(id, 2.0)[1] == 2.0 && scaleMap(id, 2.0)[10] == 20.0,

          "Something is wrong with ScaleMap");

    check(scaleWriteMap(id, 2.0)[1] == 2.0 && scaleWriteMap(id, 2.0)[10] == 20.0,

          "Something is wrong with ScaleWriteMap");

    check(negMap(id)[1] == -1.0 && negMap(id)[-10] == 10.0,

          "Something is wrong with NegMap");

    check(negWriteMap(id)[1] == -1.0 && negWriteMap(id)[-10] == 10.0,

          "Something is wrong with NegWriteMap");

    check(absMap(id)[1] == 1.0 && absMap(id)[-10] == 10.0,

          "Something is wrong with AbsMap");

  }

  // Logical maps:

  // - TrueMap, FalseMap

  // - AndMap, OrMap

  // - NotMap, NotWriteMap

  // - EqualMap, LessMap

  {

    checkConcept<BoolMap, TrueMap<A> >();

    checkConcept<BoolMap, FalseMap<A> >();

    checkConcept<BoolMap, AndMap<BoolMap,BoolMap> >();

    checkConcept<BoolMap, OrMap<BoolMap,BoolMap> >();

    checkConcept<BoolMap, NotMap<BoolMap> >();

    checkConcept<BoolWriteMap, NotWriteMap<BoolWriteMap> >();

    checkConcept<BoolMap, EqualMap<DoubleMap,DoubleMap> >();

    checkConcept<BoolMap, LessMap<DoubleMap,DoubleMap> >();

    TrueMap<int> tm;

    FalseMap<int> fm;

    RangeMap<bool> rm(2);

    rm[0] = true; rm[1] = false;

    check(andMap(tm,rm)[0] && !andMap(tm,rm)[1] && !andMap(fm,rm)[0] && !andMap(fm,rm)[1],

          "Something is wrong with AndMap");

    check(orMap(tm,rm)[0] && orMap(tm,rm)[1] && orMap(fm,rm)[0] && !orMap(fm,rm)[1],

          "Something is wrong with OrMap");

    check(!notMap(rm)[0] && notMap(rm)[1], "Something is wrong with NotMap");

    check(!notWriteMap(rm)[0] && notWriteMap(rm)[1], "Something is wrong with NotWriteMap");

    ConstMap<int, double> cm(2.0);

    IdentityMap<int> im;

    ConvertMap<IdentityMap<int>, double> id(im);

    check(lessMap(id,cm)[1] && !lessMap(id,cm)[2] && !lessMap(id,cm)[3],

          "Something is wrong with LessMap");

    check(!equalMap(id,cm)[1] && equalMap(id,cm)[2] && !equalMap(id,cm)[3],

          "Something is wrong with EqualMap");

  }

  return 0;

}