/* -*- mode: C++; indent-tabs-mode: nil; -*-

  *

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

  *

  * Copyright (C) 2003-2009

  * 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_BITS_VECTOR_MAP_H

 #define LEMON_BITS_VECTOR_MAP_H

 #include <vector>

 #include <algorithm>

 #include <lemon/core.h>

 #include <lemon/bits/alteration_notifier.h>

 #include <lemon/concept_check.h>

 #include <lemon/concepts/maps.h>

 //\ingroup graphbits

 //

 //\file

 //\brief Vector based graph maps.

 namespace lemon {

   // \ingroup graphbits

   //

   // \brief Graph map based on the std::vector storage.

   //

   // The VectorMap template class is graph map structure that automatically

   // updates the map when a key is added to or erased from the graph.

   // This map type uses std::vector to store the values.

   //

   // \tparam _Graph The graph this map is attached to.

   // \tparam _Item The item type of the graph items.

   // \tparam _Value The value type of the map.

   template <typename _Graph, typename _Item, typename _Value>

   class VectorMap

     : public ItemSetTraits<_Graph, _Item>::ItemNotifier::ObserverBase {

   private:

     // The container type of the map.

     typedef std::vector<_Value> Container;

   public:

     // The graph type of the map.

     typedef _Graph Graph;

     // The item type of the map.

     typedef _Item Item;

     // The reference map tag.

     typedef True ReferenceMapTag;

     // The key type of the map.

     typedef _Item Key;

     // The value type of the map.

     typedef _Value Value;

     // The notifier type.

     typedef typename ItemSetTraits<_Graph, _Item>::ItemNotifier Notifier;

     // The map type.

     typedef VectorMap Map;

     // The base class of the map.

     typedef typename Notifier::ObserverBase Parent;

     // The reference type of the map;

     typedef typename Container::reference Reference;

     // The const reference type of the map;

     typedef typename Container::const_reference ConstReference;

     // \brief Constructor to attach the new map into the notifier.

     //

     // It constructs a map and attachs it into the notifier.

     // It adds all the items of the graph to the map.

     VectorMap(const Graph& graph) {

       Parent::attach(graph.notifier(Item()));

       container.resize(Parent::notifier()->maxId() + 1);

     }

     // \brief Constructor uses given value to initialize the map.

     //

     // It constructs a map uses a given value to initialize the map.

     // It adds all the items of the graph to the map.

     VectorMap(const Graph& graph, const Value& value) {

       Parent::attach(graph.notifier(Item()));

       container.resize(Parent::notifier()->maxId() + 1, value);

     }

   private:

     // \brief Copy constructor

     //

     // Copy constructor.

     VectorMap(const VectorMap& _copy) : Parent() {

       if (_copy.attached()) {

         Parent::attach(*_copy.notifier());

         container = _copy.container;

       }

     }

     // \brief Assign operator.

     //

     // This operator assigns for each item in the map the

     // value mapped to the same item in the copied map.

     // The parameter map should be indiced with the same

     // itemset because this assign operator does not change

     // the container of the map.

     VectorMap& operator=(const VectorMap& cmap) {

       return operator=<VectorMap>(cmap);

     }

     // \brief Template assign operator.

     //

     // The given parameter should conform to the ReadMap

     // concecpt and could be indiced by the current item set of

     // the NodeMap. In this case the value for each item

     // is assigned by the value of the given ReadMap.

     template <typename CMap>

     VectorMap& operator=(const CMap& cmap) {

       checkConcept<concepts::ReadMap<Key, _Value>, CMap>();

       const typename Parent::Notifier* nf = Parent::notifier();

       Item it;

       for (nf->first(it); it != INVALID; nf->next(it)) {

         set(it, cmap[it]);

       }

       return *this;

     }

   public:

     // \brief The subcript operator.

     //

     // The subscript operator. The map can be subscripted by the

     // actual items of the graph.

     Reference operator[](const Key& key) {

       return container[Parent::notifier()->id(key)];

     }

     // \brief The const subcript operator.

     //

     // The const subscript operator. The map can be subscripted by the

     // actual items of the graph.

     ConstReference operator[](const Key& key) const {

       return container[Parent::notifier()->id(key)];

     }

     // \brief The setter function of the map.

     //

     // It the same as operator[](key) = value expression.

     void set(const Key& key, const Value& value) {

       (*this)[key] = value;

     }

   protected:

     // \brief Adds a new key to the map.

     //

     // It adds a new key to the map. It is called by the observer notifier

     // and it overrides the add() member function of the observer base.

     virtual void add(const Key& key) {

       int id = Parent::notifier()->id(key);

       if (id >= int(container.size())) {

         container.resize(id + 1);

       }

     }

     // \brief Adds more new keys to the map.

     //

     // It adds more new keys to the map. It is called by the observer notifier

     // and it overrides the add() member function of the observer base.

     virtual void add(const std::vector<Key>& keys) {

       int max = container.size() - 1;

       for (int i = 0; i < int(keys.size()); ++i) {

         int id = Parent::notifier()->id(keys[i]);

         if (id >= max) {

           max = id;

         }

       }

       container.resize(max + 1);

     }

     // \brief Erase a key from the map.

     //

     // Erase a key from the map. It is called by the observer notifier

     // and it overrides the erase() member function of the observer base.

     virtual void erase(const Key& key) {

       container[Parent::notifier()->id(key)] = Value();

     }

     // \brief Erase more keys from the map.

     //

     // It erases more keys from the map. It is called by the observer notifier

     // and it overrides the erase() member function of the observer base.

     virtual void erase(const std::vector<Key>& keys) {

       for (int i = 0; i < int(keys.size()); ++i) {

         container[Parent::notifier()->id(keys[i])] = Value();

       }

     }

     // \brief Build the map.

     //

     // It builds the map. It is called by the observer notifier

     // and it overrides the build() member function of the observer base.

     virtual void build() {

       int size = Parent::notifier()->maxId() + 1;

       container.reserve(size);

       container.resize(size);

     }

     // \brief Clear the map.

     //

     // It erases all items from the map. It is called by the observer notifier

     // and it overrides the clear() member function of the observer base.

     virtual void clear() {

       container.clear();

     }

   private:

     Container container;

   };

 }

 #endif