/* -*- C++ -*-

 * lemon/iterable_maps.h - Part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2006 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 <lemon/traits.h>

#include <lemon/invalid.h>

#include <vector>

#include <limits>

///\ingroup maps

///\file

///\brief Maps that makes it possible to iterate through the keys having

///a certain value

///

///

namespace lemon {

  ///\ingroup maps

  ///

  /// \brief Dynamic iterable bool map.

  ///

  /// This class provides a special graph map type which can store

  /// for each graph item(node, edge, etc.) a bool value. For both 

  /// the true and the false it is possible to iterate on the keys which

  /// mapped to the given value.

  /// 

  /// \param _Graph The graph type.

  /// \param _Item One of the graph's item type, the key of the map.

  template <typename _Graph, typename _Item>

  class IterableBoolMap 

    : protected ItemSetTraits<_Graph, _Item>::template Map<int>::Parent {

  private:

    typedef _Graph Graph;

    typedef _Item Item;

    typedef typename ItemSetTraits<Graph, Item>::ItemIt ItemIt;

    typedef typename ItemSetTraits<Graph, Item>

    ::template Map<int>::Parent Parent;

    std::vector<Item> array;

    int sep;

    const Graph& graph;

  private:

    int position(const Item& item) const {

      return Parent::operator[](item);

    }

  public:

    /// Indicates that the map if reference map.

    typedef True ReferenceMapTag;

    /// The key type

    typedef Item Key;

    /// The value type

    typedef bool Value;

    /// The const reference type.    

    typedef const Value& ConstReference;

    /// \brief Refernce to the value of the map.

    ///

    /// This class is near to similar to the bool type. It can

    /// be converted to bool and it has the same operators.

    class Reference {

      friend class IterableBoolMap;

    private:

      Reference(IterableBoolMap& map, const Key& key) 

	: _key(key), _map(map) {} 

    public:

      Reference& operator=(const Reference& value) {

	_map.set(_key, (bool)value);

 	return *this;

      }

      operator bool() const { 

	return static_cast<const IterableBoolMap&>(_map)[_key]; 

      }

      Reference& operator=(bool value) { 

	_map.set(_key, value); 

	return *this; 

      }

      Reference& operator&=(bool value) {

	_map.set(_key, _map[_key] & value); 

	return *this; 	

      }

      Reference& operator|=(bool value) {

	_map.set(_key, _map[_key] | value); 

	return *this; 	

      }

      Reference& operator^=(bool value) {

	_map.set(_key, _map[_key] ^ value); 

	return *this; 	

      }

    private:

      Key _key;

      IterableBoolMap& _map; 

    };

    /// \brief Constructor of the Map with a default value.

    ///

    /// Constructor of the Map with a default value.

    IterableBoolMap(const Graph& _graph, bool def = false) 

      : Parent(_graph), graph(_graph) {

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

        Parent::set(it, array.size());

        array.push_back(it);

      }

      sep = (def ? array.size() : 0);

    }

    /// \brief Const subscript operator of the map.

    ///

    /// Const subscript operator of the map.

    bool operator[](const Item& item) const {

      return position(item) < sep;

    }

    /// \brief Subscript operator of the map.

    ///

    /// Subscript operator of the map.

    Reference operator[](const Item& item) {

      return Reference(*this, item);

    }

    /// \brief Set operation of the map.

    ///

    /// Set operation of the map.

    void set(const Item& item, bool value) {

      int pos = position(item);

      if (value) {

        if (pos < sep) return;

        Item tmp = array[sep];

        array[sep] = item;

        Parent::set(item, sep);

        array[pos] = tmp;

        Parent::set(tmp, pos); 

        ++sep;

      } else {

        if (pos >= sep) return;

        --sep;

        Item tmp = array[sep];

        array[sep] = item;

        Parent::set(item, sep);

        array[pos] = tmp;

        Parent::set(tmp, pos);

      }

    }

    /// \brief Returns the number of the items mapped to true.

    ///

    /// Returns the number of the items mapped to true.

    int trueNum() const {

      return sep;

    } 

    /// \brief Returns the number of the items mapped to false.

    ///

    /// Returns the number of the items mapped to false.

    int falseNum() const {

      return array.size() - sep;

    }

    /// \brief Iterator for the keys mapped to true.

    ///

    /// Iterator for the keys mapped to true. It works

    /// like a graph item iterator in the map, it can be converted

    /// the item type of the map, incremented with \c ++ operator, and

    /// if the iterator leave the last valid item it will be equal to 

    /// \c INVALID.

    class TrueIt : public Item {

    public:

      typedef Item Parent;

      /// \brief Creates an iterator.

      ///

      /// Creates an iterator. It iterates on the 

      /// keys which mapped to true.

      /// \param map The IterableIntMap

      TrueIt(const IterableBoolMap& _map) 

        : Parent(_map.sep > 0 ? _map.array[_map.sep - 1] : INVALID), 

          map(&_map) {}

      /// \brief Invalid constructor \& conversion.

      ///

      /// This constructor initializes the item to be invalid.

      /// \sa Invalid for more details.

      TrueIt(Invalid) : Parent(INVALID), map(0) {}

      /// \brief Increment operator.

      ///

      /// Increment Operator.

      TrueIt& operator++() {

        int pos = map->position(*this);

        Parent::operator=(pos > 0 ? map->array[pos - 1] : INVALID);

        return *this;

      }

    private:

      const IterableBoolMap* map;

    };

    /// \brief Iterator for the keys mapped to false.

    ///

    /// Iterator for the keys mapped to false. It works

    /// like a graph item iterator in the map, it can be converted

    /// the item type of the map, incremented with \c ++ operator, and

    /// if the iterator leave the last valid item it will be equal to 

    /// \c INVALID.

    class FalseIt : public Item {

    public:

      typedef Item Parent;

      /// \brief Creates an iterator.

      ///

      /// Creates an iterator. It iterates on the 

      /// keys which mapped to false.

      /// \param map The IterableIntMap

      FalseIt(const IterableBoolMap& _map) 

        : Parent(_map.sep < _map.array.size() ? _map.array.back() : INVALID), 

          map(&_map) {}

      /// \brief Invalid constructor \& conversion.

      ///

      /// This constructor initializes the item to be invalid.

      /// \sa Invalid for more details.

      FalseIt(Invalid) : Parent(INVALID), map(0) {}

      /// \brief Increment operator.

      ///

      /// Increment Operator.

      FalseIt& operator++() {

        int pos = map->position(*this);

        Parent::operator=(pos > map->sep ? map->array[pos - 1] : INVALID);

        return *this;

      }

    private:

      const IterableBoolMap* map;

    };

  protected:

    virtual void add(const Item& item) {

      Parent::add(item);

      Parent::set(item, array.size());

      array.push_back(item);

    }

    virtual void add(const std::vector<Item>& items) {

      Parent::add(items);

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

        Parent::set(items[i], array.size());

        array.push_back(items[i]);

      }

    }

    virtual void erase(const Item& item) {

      int pos = position(item); 

      if (pos < sep) {

        --sep;

        Parent::set(array[sep], pos);

        array[pos] = array[sep];

        Parent::set(array.back(), sep);

        array[sep] = array.back();

        array.pop_back();

      } else {

        Parent::set(array.back(), pos);

        array[pos] = array.back();

        array.pop_back();

      }

      Parent::erase(item);

    }

    virtual void erase(const std::vector<Item>& items) {

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

        int pos = position(items[i]); 

        if (pos < sep) {

          --sep;

          Parent::set(array[sep], pos);

          array[pos] = array[sep];

          Parent::set(array.back(), sep);

          array[sep] = array.back();

          array.pop_back();

        } else {

          Parent::set(array.back(), pos);

          array[pos] = array.back();

          array.pop_back();

        }

      }

      Parent::erase(items);

    }    

    virtual void build() {

      Parent::build();

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

        Parent::set(it, array.size());

        array.push_back(it);

      }

      sep = 0;      

    }

    virtual void clear() {

      array.clear();

      sep = 0;

      Parent::clear();

    }

  };

  namespace _iterable_maps_bits {

    template <typename Item>

    struct IterableIntMapNode {

      IterableIntMapNode() : value(-1) {}

      IterableIntMapNode(int _value) : value(_value) {}

      Item prev, next;

      int value;

    };

  }

  ///\ingroup maps

  ///

  /// \brief Dynamic iterable integer map.

  ///

  /// This class provides a special graph map type which can store

  /// for each graph item(node, edge, etc.) an integer value. For each

  /// non negative value it is possible to iterate on the keys which

  /// mapped to the given value.

  /// 

  /// \param _Graph The graph type.

  /// \param _Item One of the graph's item type, the key of the map.

  template <typename _Graph, typename _Item>

  class IterableIntMap : protected ItemSetTraits<_Graph, _Item> 

  ::template Map<_iterable_maps_bits::IterableIntMapNode<_Item> >::Parent {

  public:

    typedef typename ItemSetTraits<_Graph, _Item> 

    ::template Map<_iterable_maps_bits::IterableIntMapNode<_Item> >

    ::Parent Parent;

    /// The key type

    typedef _Item Key;

    /// The value type

    typedef int Value;

    /// The graph type

    typedef _Graph Graph;

    /// \brief Constructor of the Map.

    ///

    /// Constructor of the Map. It set all values -1.

    explicit IterableIntMap(const Graph& graph) 

      : Parent(graph) {}

    /// \brief Constructor of the Map with a given value.

    ///

    /// Constructor of the Map with a given value.

    explicit IterableIntMap(const Graph& graph, int value) 

      : Parent(graph, _iterable_maps_bits::IterableIntMapNode<_Item>(value)) {

      if (value >= 0) {

	for (typename Parent::ItemIt it(*this); it != INVALID; ++it) {

	  lace(it);

	}

      }

    }

  private:

    void unlace(const Key& key) {

      typename Parent::Value& node = Parent::operator[](key);

      if (node.value < 0) return;

      if (node.prev != INVALID) {

	Parent::operator[](node.prev).next = node.next;	

      } else {

	first[node.value] = node.next;

      }

      if (node.next != INVALID) {

	Parent::operator[](node.next).prev = node.prev;

      }

      while (!first.empty() && first.back() == INVALID) {

	first.pop_back();

      }

    }

    void lace(const Key& key) {

      typename Parent::Value& node = Parent::operator[](key);

      if (node.value < 0) return;

      if (node.value >= (int)first.size()) {

	first.resize(node.value + 1, INVALID);

      } 

      node.prev = INVALID;

      node.next = first[node.value];

      if (node.next != INVALID) {

	Parent::operator[](node.next).prev = key;	

      }

      first[node.value] = key;

    }

  public:

    /// Indicates that the map if reference map.

    typedef True ReferenceMapTag;

    /// \brief Refernce to the value of the map.

    ///

    /// This class is near to similar to the int type. It can

    /// be converted to int and it has the same operators.

    class Reference {

      friend class IterableIntMap;

    private:

      Reference(IterableIntMap& map, const Key& key) 

	: _key(key), _map(map) {} 

    public:

      Reference& operator=(const Reference& value) {

	_map.set(_key, (const int&)value);

 	return *this;

      }

      operator const int&() const { 

	return static_cast<const IterableIntMap&>(_map)[_key]; 

      }

      Reference& operator=(int value) { 

	_map.set(_key, value); 

	return *this; 

      }

      Reference& operator++() {

	_map.set(_key, _map[_key] + 1); 

	return *this; 	

      }

      int operator++(int) {

	int value = _map[_key];

	_map.set(_key, value + 1); 

	return value; 	

      }

      Reference& operator--() {

	_map.set(_key, _map[_key] - 1); 

	return *this; 	

      }

      int operator--(int) {

	int value = _map[_key];

	_map.set(_key, value - 1); 

	return value; 	

      }

      Reference& operator+=(int value) { 

	_map.set(_key, _map[_key] + value); 

	return *this;

      }

      Reference& operator-=(int value) { 

	_map.set(_key, _map[_key] - value); 

	return *this;

      }

      Reference& operator*=(int value) { 

	_map.set(_key, _map[_key] * value); 

	return *this;

      }

      Reference& operator/=(int value) { 

	_map.set(_key, _map[_key] / value); 

	return *this;

      }

      Reference& operator%=(int value) { 

	_map.set(_key, _map[_key] % value); 

	return *this;

      }

      Reference& operator&=(int value) { 

	_map.set(_key, _map[_key] & value); 

	return *this;

      }

      Reference& operator|=(int value) { 

	_map.set(_key, _map[_key] | value); 

	return *this;

      }

      Reference& operator^=(int value) { 

	_map.set(_key, _map[_key] ^ value); 

	return *this;

      }

      Reference& operator<<=(int value) { 

	_map.set(_key, _map[_key] << value); 

	return *this;

      }

      Reference& operator>>=(int value) { 

	_map.set(_key, _map[_key] >> value); 

	return *this;

      }

    private:

      Key _key;

      IterableIntMap& _map; 

    };

    /// The const reference type.    

    typedef const Value& ConstReference;

    /// \brief Gives back the maximal value plus one.

    ///

    /// Gives back the maximal value plus one.

    int size() const {

      return (int)first.size();

    }

    /// \brief Set operation of the map.

    ///

    /// Set operation of the map.

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

      unlace(key);

      Parent::operator[](key).value = value;

      lace(key);

    }

    /// \brief Const subscript operator of the map.

    ///

    /// Const subscript operator of the map.

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

      return Parent::operator[](key).value;

    }

    /// \brief Subscript operator of the map.

    ///

    /// Subscript operator of the map.

    Reference operator[](const Key& key) {

      return Reference(*this, key);

    }

    /// \brief Iterator for the keys with the same value.

    ///

    /// Iterator for the keys with the same value. It works

    /// like a graph item iterator in the map, it can be converted

    /// the item type of the map, incremented with \c ++ operator, and

    /// if the iterator leave the last valid item it will be equal to 

    /// \c INVALID.

    class ItemIt : public _Item {

    public:

      typedef _Item Parent;

      /// \brief Invalid constructor \& conversion.

      ///

      /// This constructor initializes the item to be invalid.

      /// \sa Invalid for more details.

      ItemIt(Invalid) : Parent(INVALID), _map(0) {}

      /// \brief Creates an iterator with a value.

      ///

      /// Creates an iterator with a value. It iterates on the 

      /// keys which have the given value.

      /// \param map The IterableIntMap

      /// \param value The value

      ItemIt(const IterableIntMap& map, int value) : _map(&map) {

	if (value < 0 || value >= (int)_map->first.size()) {	  

	  Parent::operator=(INVALID);

	} else {

	  Parent::operator=(_map->first[value]);

	}

      } 

      /// \brief Increment operator.

      ///

      /// Increment Operator.

      ItemIt& operator++() {

	Parent::operator=(_map->IterableIntMap::Parent::

			  operator[](static_cast<Parent&>(*this)).next);

	return *this;

      }

    private:

      const IterableIntMap* _map;

    };

  protected:

    virtual void erase(const Key& key) {

      unlace(key);

      Parent::erase(key);

    }

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

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

        unlace(keys[i]);

      }

      Parent::erase(keys);

    }

    virtual void clear() {

      first.clear();

      Parent::clear();

    }

  private:

    std::vector<_Item> first;

  };

  /// @}

}