lemon/bits/vector_map.h
author Peter Kovacs <kpeter@inf.elte.hu>
Fri, 13 Nov 2009 00:10:33 +0100
changeset 815 aef153f430e1
parent 492 9605e051942f
permissions -rw-r--r--
Entirely rework cycle canceling algorithms (#180)

- Move the cycle canceling algorithms (CycleCanceling, CancelAndTighten)
into one class (CycleCanceling).
- Add a Method parameter to the run() function to be able to select
the used cycle canceling method.
- Use the new interface similarly to NetworkSimplex.
- Rework the implementations using an efficient internal structure
for handling the residual network.
This improvement made the codes much faster.
- Handle GEQ supply type (LEQ is not supported).
- Handle infinite upper bounds.
- Handle negative costs (for arcs of finite upper bound).
- Extend the documentation.
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     5  * Copyright (C) 2003-2009
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #ifndef LEMON_BITS_VECTOR_MAP_H
    20 #define LEMON_BITS_VECTOR_MAP_H
    21 
    22 #include <vector>
    23 #include <algorithm>
    24 
    25 #include <lemon/core.h>
    26 #include <lemon/bits/alteration_notifier.h>
    27 
    28 #include <lemon/concept_check.h>
    29 #include <lemon/concepts/maps.h>
    30 
    31 //\ingroup graphbits
    32 //
    33 //\file
    34 //\brief Vector based graph maps.
    35 namespace lemon {
    36 
    37   // \ingroup graphbits
    38   //
    39   // \brief Graph map based on the std::vector storage.
    40   //
    41   // The VectorMap template class is graph map structure that automatically
    42   // updates the map when a key is added to or erased from the graph.
    43   // This map type uses std::vector to store the values.
    44   //
    45   // \tparam _Graph The graph this map is attached to.
    46   // \tparam _Item The item type of the graph items.
    47   // \tparam _Value The value type of the map.
    48   template <typename _Graph, typename _Item, typename _Value>
    49   class VectorMap
    50     : public ItemSetTraits<_Graph, _Item>::ItemNotifier::ObserverBase {
    51   private:
    52 
    53     // The container type of the map.
    54     typedef std::vector<_Value> Container;
    55 
    56   public:
    57 
    58     // The graph type of the map.
    59     typedef _Graph GraphType;
    60     // The item type of the map.
    61     typedef _Item Item;
    62     // The reference map tag.
    63     typedef True ReferenceMapTag;
    64 
    65     // The key type of the map.
    66     typedef _Item Key;
    67     // The value type of the map.
    68     typedef _Value Value;
    69 
    70     // The notifier type.
    71     typedef typename ItemSetTraits<_Graph, _Item>::ItemNotifier Notifier;
    72 
    73     // The map type.
    74     typedef VectorMap Map;
    75 
    76     // The reference type of the map;
    77     typedef typename Container::reference Reference;
    78     // The const reference type of the map;
    79     typedef typename Container::const_reference ConstReference;
    80 
    81   private:
    82 
    83     // The base class of the map.
    84     typedef typename Notifier::ObserverBase Parent;
    85 
    86   public:
    87 
    88     // \brief Constructor to attach the new map into the notifier.
    89     //
    90     // It constructs a map and attachs it into the notifier.
    91     // It adds all the items of the graph to the map.
    92     VectorMap(const GraphType& graph) {
    93       Parent::attach(graph.notifier(Item()));
    94       container.resize(Parent::notifier()->maxId() + 1);
    95     }
    96 
    97     // \brief Constructor uses given value to initialize the map.
    98     //
    99     // It constructs a map uses a given value to initialize the map.
   100     // It adds all the items of the graph to the map.
   101     VectorMap(const GraphType& graph, const Value& value) {
   102       Parent::attach(graph.notifier(Item()));
   103       container.resize(Parent::notifier()->maxId() + 1, value);
   104     }
   105 
   106   private:
   107     // \brief Copy constructor
   108     //
   109     // Copy constructor.
   110     VectorMap(const VectorMap& _copy) : Parent() {
   111       if (_copy.attached()) {
   112         Parent::attach(*_copy.notifier());
   113         container = _copy.container;
   114       }
   115     }
   116 
   117     // \brief Assign operator.
   118     //
   119     // This operator assigns for each item in the map the
   120     // value mapped to the same item in the copied map.
   121     // The parameter map should be indiced with the same
   122     // itemset because this assign operator does not change
   123     // the container of the map.
   124     VectorMap& operator=(const VectorMap& cmap) {
   125       return operator=<VectorMap>(cmap);
   126     }
   127 
   128 
   129     // \brief Template assign operator.
   130     //
   131     // The given parameter should conform to the ReadMap
   132     // concecpt and could be indiced by the current item set of
   133     // the NodeMap. In this case the value for each item
   134     // is assigned by the value of the given ReadMap.
   135     template <typename CMap>
   136     VectorMap& operator=(const CMap& cmap) {
   137       checkConcept<concepts::ReadMap<Key, _Value>, CMap>();
   138       const typename Parent::Notifier* nf = Parent::notifier();
   139       Item it;
   140       for (nf->first(it); it != INVALID; nf->next(it)) {
   141         set(it, cmap[it]);
   142       }
   143       return *this;
   144     }
   145 
   146   public:
   147 
   148     // \brief The subcript operator.
   149     //
   150     // The subscript operator. The map can be subscripted by the
   151     // actual items of the graph.
   152     Reference operator[](const Key& key) {
   153       return container[Parent::notifier()->id(key)];
   154     }
   155 
   156     // \brief The const subcript operator.
   157     //
   158     // The const subscript operator. The map can be subscripted by the
   159     // actual items of the graph.
   160     ConstReference operator[](const Key& key) const {
   161       return container[Parent::notifier()->id(key)];
   162     }
   163 
   164 
   165     // \brief The setter function of the map.
   166     //
   167     // It the same as operator[](key) = value expression.
   168     void set(const Key& key, const Value& value) {
   169       (*this)[key] = value;
   170     }
   171 
   172   protected:
   173 
   174     // \brief Adds a new key to the map.
   175     //
   176     // It adds a new key to the map. It is called by the observer notifier
   177     // and it overrides the add() member function of the observer base.
   178     virtual void add(const Key& key) {
   179       int id = Parent::notifier()->id(key);
   180       if (id >= int(container.size())) {
   181         container.resize(id + 1);
   182       }
   183     }
   184 
   185     // \brief Adds more new keys to the map.
   186     //
   187     // It adds more new keys to the map. It is called by the observer notifier
   188     // and it overrides the add() member function of the observer base.
   189     virtual void add(const std::vector<Key>& keys) {
   190       int max = container.size() - 1;
   191       for (int i = 0; i < int(keys.size()); ++i) {
   192         int id = Parent::notifier()->id(keys[i]);
   193         if (id >= max) {
   194           max = id;
   195         }
   196       }
   197       container.resize(max + 1);
   198     }
   199 
   200     // \brief Erase a key from the map.
   201     //
   202     // Erase a key from the map. It is called by the observer notifier
   203     // and it overrides the erase() member function of the observer base.
   204     virtual void erase(const Key& key) {
   205       container[Parent::notifier()->id(key)] = Value();
   206     }
   207 
   208     // \brief Erase more keys from the map.
   209     //
   210     // It erases more keys from the map. It is called by the observer notifier
   211     // and it overrides the erase() member function of the observer base.
   212     virtual void erase(const std::vector<Key>& keys) {
   213       for (int i = 0; i < int(keys.size()); ++i) {
   214         container[Parent::notifier()->id(keys[i])] = Value();
   215       }
   216     }
   217 
   218     // \brief Build the map.
   219     //
   220     // It builds the map. It is called by the observer notifier
   221     // and it overrides the build() member function of the observer base.
   222     virtual void build() {
   223       int size = Parent::notifier()->maxId() + 1;
   224       container.reserve(size);
   225       container.resize(size);
   226     }
   227 
   228     // \brief Clear the map.
   229     //
   230     // It erases all items from the map. It is called by the observer notifier
   231     // and it overrides the clear() member function of the observer base.
   232     virtual void clear() {
   233       container.clear();
   234     }
   235 
   236   private:
   237 
   238     Container container;
   239 
   240   };
   241 
   242 }
   243 
   244 #endif