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// -*- C++ -*-

// Copyright (C) 2005, 2006, 2007, 2009, 2010, 2011

// Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the terms

// of the GNU General Public License as published by the Free Software

// Foundation; either version 3, or (at your option) any later

// version.

// This library is distributed in the hope that it will be useful, but

// WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

// General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional

// permissions described in the GCC Runtime Library Exception, version

// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and

// a copy of the GCC Runtime Library Exception along with this program;

// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

// <http://www.gnu.org/licenses/>.

// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.

// Permission to use, copy, modify, sell, and distribute this software

// is hereby granted without fee, provided that the above copyright

// notice appears in all copies, and that both that copyright notice

// and this permission notice appear in supporting documentation. None

// of the above authors, nor IBM Haifa Research Laboratories, make any

// representation about the suitability of this software for any

// purpose. It is provided "as is" without express or implied

// warranty.

/**

 * @file trie_policy.hpp

 * Contains trie-related policies.

 */

#ifndef PB_DS_TRIE_POLICY_HPP

#define PB_DS_TRIE_POLICY_HPP

#include <bits/c++config.h>

#include <string>

#include <ext/pb_ds/detail/type_utils.hpp>

#include <ext/pb_ds/detail/trie_policy/trie_policy_base.hpp>

namespace __gnu_pbds

{

#define PB_DS_CLASS_T_DEC \

  template<typename String, typename String::value_type Min_E_Val, \

           typename String::value_type Max_E_Val, bool Reverse, \

           typename _Alloc>

#define PB_DS_CLASS_C_DEC \

  trie_string_access_traits<String, Min_E_Val,Max_E_Val,Reverse,_Alloc>

  /**

   *  Element access traits for string types.

   *

   *  @tparam String            String type.

   *  @tparam Min_E_Val         Minimal element value.

   *  @tparam Max_E_Val         Maximum element value.

   *  @tparam Reverse           Reverse iteration should be used.

   *                            Default: false.

   *  @tparam _Alloc            Allocator type.

   */

  template<typename String = std::string,

           typename String::value_type Min_E_Val = detail::__numeric_traits<typename String::value_type>::__min,

           typename String::value_type Max_E_Val = detail::__numeric_traits<typename String::value_type>::__max,

           bool Reverse = false,

           typename _Alloc = std::allocator<char> >

  struct trie_string_access_traits

  {

  public:

    typedef typename _Alloc::size_type                    size_type;

    typedef String                                        key_type;

    typedef typename _Alloc::template rebind<key_type>    __rebind_k;

    typedef typename __rebind_k::other::const_reference   key_const_reference;

    enum

      {

        reverse = Reverse

      };

    /// Element const iterator type.

    typedef typename detail::__conditional_type<Reverse, \

                       typename String::const_reverse_iterator, \

                       typename String::const_iterator>::__type const_iterator;

    /// Element type.

    typedef typename std::iterator_traits<const_iterator>::value_type e_type;

    enum

      {

        min_e_val = Min_E_Val,

        max_e_val = Max_E_Val,

        max_size = max_e_val - min_e_val + 1

      };

    PB_DS_STATIC_ASSERT(min_max_size, max_size >= 2);

    /// Returns a const_iterator to the first element of

    /// key_const_reference agumnet.

    inline static const_iterator

    begin(key_const_reference);

    /// Returns a const_iterator to the after-last element of

    /// key_const_reference argument.

    inline static const_iterator

    end(key_const_reference);

    /// Maps an element to a position.

    inline static size_type

    e_pos(e_type e);

  private:

    inline static const_iterator

    begin_imp(key_const_reference, detail::false_type);

    inline static const_iterator

    begin_imp(key_const_reference, detail::true_type);

    inline static const_iterator

    end_imp(key_const_reference, detail::false_type);

    inline static const_iterator

    end_imp(key_const_reference, detail::true_type);

    static detail::integral_constant<int, Reverse> s_rev_ind;

  };

#include <ext/pb_ds/detail/trie_policy/trie_string_access_traits_imp.hpp>

#undef PB_DS_CLASS_T_DEC

#undef PB_DS_CLASS_C_DEC

#define PB_DS_CLASS_T_DEC \

  template<typename Node_CItr,typename Node_Itr, \

           typename _ATraits, typename _Alloc>

#define PB_DS_CLASS_C_DEC \

  trie_prefix_search_node_update<Node_CItr, Node_Itr, \

                                 _ATraits,_Alloc>

#define PB_DS_TRIE_POLICY_BASE \

  detail::trie_policy_base<Node_CItr,Node_Itr,_ATraits, _Alloc>

  /// A node updator that allows tries to be searched for the range of

  /// values that match a certain prefix.

  template<typename Node_CItr,

           typename Node_Itr,

           typename _ATraits,

           typename _Alloc>

  class trie_prefix_search_node_update : private PB_DS_TRIE_POLICY_BASE

  {

  private:

    typedef PB_DS_TRIE_POLICY_BASE                      base_type;

  public:

    typedef typename base_type::key_type                key_type;

    typedef typename base_type::key_const_reference     key_const_reference;

    /// Element access traits.

    typedef _ATraits                            access_traits;

    /// Const element iterator.

    typedef typename access_traits::const_iterator      a_const_iterator;

    /// _Alloc type.

    typedef _Alloc                                      allocator_type;

    /// Size type.

    typedef typename allocator_type::size_type          size_type;

    typedef null_type                                   metadata_type;

    typedef Node_Itr                                    node_iterator;

    typedef Node_CItr                                   node_const_iterator;

    typedef typename node_iterator::value_type          iterator;

    typedef typename node_const_iterator::value_type    const_iterator;

    /// Finds the const iterator range corresponding to all values

    /// whose prefixes match r_key.

    std::pair<const_iterator, const_iterator>

    prefix_range(key_const_reference) const;

    /// Finds the iterator range corresponding to all values whose

    /// prefixes match r_key.

    std::pair<iterator, iterator>

    prefix_range(key_const_reference);

    /// Finds the const iterator range corresponding to all values

    /// whose prefixes match [b, e).

    std::pair<const_iterator, const_iterator>

    prefix_range(a_const_iterator, a_const_iterator) const;

    /// Finds the iterator range corresponding to all values whose

    /// prefixes match [b, e).

    std::pair<iterator, iterator>

    prefix_range(a_const_iterator, a_const_iterator);

  protected:

    /// Called to update a node's metadata.

    inline void

    operator()(node_iterator node_it, node_const_iterator end_nd_it) const;

  private:

    node_iterator

    next_child(node_iterator, a_const_iterator, a_const_iterator,

               node_iterator, const access_traits&);

    /// Returns the const iterator associated with the just-after last element.

    virtual const_iterator

    end() const = 0;

    /// Returns the iterator associated with the just-after last element.

    virtual iterator

    end() = 0;

    /// Returns the node_const_iterator associated with the trie's root node.

    virtual node_const_iterator

    node_begin() const = 0;

    /// Returns the node_iterator associated with the trie's root node.

    virtual node_iterator

    node_begin() = 0;

    /// Returns the node_const_iterator associated with a just-after leaf node.

    virtual node_const_iterator

    node_end() const = 0;

    /// Returns the node_iterator associated with a just-after leaf node.

    virtual node_iterator

    node_end() = 0;

    /// Access to the cmp_fn object.

    virtual const access_traits&

    get_access_traits() const = 0;

  };

#include <ext/pb_ds/detail/trie_policy/prefix_search_node_update_imp.hpp>

#undef PB_DS_CLASS_C_DEC

#define PB_DS_CLASS_C_DEC \

  trie_order_statistics_node_update<Node_CItr, Node_Itr, \

                                    _ATraits, _Alloc>

  /// Functor updating ranks of entrees.

  template<typename Node_CItr,

           typename Node_Itr,

           typename _ATraits,

           typename _Alloc>

  class trie_order_statistics_node_update : private PB_DS_TRIE_POLICY_BASE

  {

  private:

    typedef PB_DS_TRIE_POLICY_BASE                      base_type;

  public:

    typedef _ATraits                            access_traits;

    typedef typename access_traits::const_iterator      a_const_iterator;

    typedef _Alloc                                      allocator_type;

    typedef typename allocator_type::size_type          size_type;

    typedef typename base_type::key_type                key_type;

    typedef typename base_type::key_const_reference     key_const_reference;

    typedef size_type                                   metadata_type;

    typedef Node_CItr                                   node_const_iterator;

    typedef Node_Itr                                    node_iterator;

    typedef typename node_const_iterator::value_type    const_iterator;

    typedef typename node_iterator::value_type          iterator;

    /// Finds an entry by __order. Returns a const_iterator to the

    /// entry with the __order order, or a const_iterator to the

    /// container object's end if order is at least the size of the

    /// container object.

    inline const_iterator

    find_by_order(size_type) const;

    /// Finds an entry by __order. Returns an iterator to the entry

    /// with the __order order, or an iterator to the container

    /// object's end if order is at least the size of the container

    /// object.

    inline iterator

    find_by_order(size_type);

    /// Returns the order of a key within a sequence. For exapmle, if

    /// r_key is the smallest key, this method will return 0; if r_key

    /// is a key between the smallest and next key, this method will

    /// return 1; if r_key is a key larger than the largest key, this

    /// method will return the size of r_c.

    inline size_type

    order_of_key(key_const_reference) const;

    /// Returns the order of a prefix within a sequence. For exapmle,

    /// if [b, e] is the smallest prefix, this method will return 0; if

    /// r_key is a key between the smallest and next key, this method

    /// will return 1; if r_key is a key larger than the largest key,

    /// this method will return the size of r_c.

    inline size_type

    order_of_prefix(a_const_iterator, a_const_iterator) const;

  protected:

    /// Updates the rank of a node through a node_iterator node_it;

    /// end_nd_it is the end node iterator.

    inline void

    operator()(node_iterator, node_const_iterator) const;

  private:

    typedef typename base_type::const_reference         const_reference;

    typedef typename base_type::const_pointer           const_pointer;

    typedef typename _Alloc::template rebind<metadata_type> __rebind_m;

    typedef typename __rebind_m::other                  __rebind_ma;

    typedef typename __rebind_ma::const_reference      metadata_const_reference;

    typedef typename __rebind_ma::reference             metadata_reference;

    /// Returns true if the container is empty.

    virtual bool

    empty() const = 0;

    /// Returns the iterator associated with the trie's first element.

    virtual iterator

    begin() = 0;

    /// Returns the iterator associated with the trie's

    /// just-after-last element.

    virtual iterator

    end() = 0;

    /// Returns the node_const_iterator associated with the trie's root node.

    virtual node_const_iterator

    node_begin() const = 0;

    /// Returns the node_iterator associated with the trie's root node.

    virtual node_iterator

    node_begin() = 0;

    /// Returns the node_const_iterator associated with a just-after

    /// leaf node.

    virtual node_const_iterator

    node_end() const = 0;

    /// Returns the node_iterator associated with a just-after leaf node.

    virtual node_iterator

    node_end() = 0;

    /// Access to the cmp_fn object.

    virtual access_traits&

    get_access_traits() = 0;

  };

#include <ext/pb_ds/detail/trie_policy/order_statistics_imp.hpp>

#undef PB_DS_CLASS_T_DEC

#undef PB_DS_CLASS_C_DEC

#undef PB_DS_TRIE_POLICY_BASE

} // namespace __gnu_pbds

#endif