libstdc++-v3/include/ext/pb_ds/trie_policy.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2024 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 3, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  26
  27 // Permission to use, copy, modify, sell, and distribute this software
  28 // is hereby granted without fee, provided that the above copyright
  29 // notice appears in all copies, and that both that copyright notice
  30 // and this permission notice appear in supporting documentation. None
  31 // of the above authors, nor IBM Haifa Research Laboratories, make any
  32 // representation about the suitability of this software for any
  33 // purpose. It is provided "as is" without express or implied
  34 // warranty.
  35
  36 /**
  37  * @file trie_policy.hpp
  38  * Contains trie-related policies.
  39  */
  40
  41 #ifndef PB_DS_TRIE_POLICY_HPP
  42 #define PB_DS_TRIE_POLICY_HPP
  43
  44 #include <bits/c++config.h>
  45 #include <string>
  46 #include <ext/pb_ds/detail/type_utils.hpp>
  47 #include <ext/pb_ds/detail/trie_policy/trie_policy_base.hpp>
  48
  49 namespace __gnu_pbds
  50 {
  51 #define PB_DS_CLASS_T_DEC \
  52   template<typename String, typename String::value_type Min_E_Val, \
  53            typename String::value_type Max_E_Val, bool Reverse, \
  54            typename _Alloc>
  55
  56 #define PB_DS_CLASS_C_DEC \
  57   trie_string_access_traits<String, Min_E_Val,Max_E_Val,Reverse,_Alloc>
  58
  59   /**
  60    *  Element access traits for string types.
  61    *
  62    *  @tparam String            String type.
  63    *  @tparam Min_E_Val         Minimal element value.
  64    *  @tparam Max_E_Val         Maximum element value.
  65    *  @tparam Reverse           Reverse iteration should be used.
  66    *                            Default: false.
  67    *  @tparam _Alloc            Allocator type.
  68    */
  69   template<typename String = std::string,
  70            typename String::value_type Min_E_Val = detail::__numeric_traits<typename String::value_type>::__min,
  71            typename String::value_type Max_E_Val = detail::__numeric_traits<typename String::value_type>::__max,
  72            bool Reverse = false,
  73            typename _Alloc = std::allocator<char> >
  74   struct trie_string_access_traits
  75   {
  76   public:
  77     typedef typename _Alloc::size_type                    size_type;
  78     typedef String                                        key_type;
  79     typedef typename detail::rebind_traits<_Alloc, key_type>::const_reference
  80       key_const_reference;
  81
  82     enum
  83       {
  84         reverse = Reverse
  85       };
  86
  87     /// Element const iterator type.
  88     typedef typename detail::__conditional_type<Reverse, \
  89                        typename String::const_reverse_iterator, \
  90                        typename String::const_iterator>::__type const_iterator;
  91
  92     /// Element type.
  93     typedef typename std::iterator_traits<const_iterator>::value_type e_type;
  94
  95     enum
  96       {
  97         min_e_val = Min_E_Val,
  98         max_e_val = Max_E_Val,
  99         max_size = max_e_val - min_e_val + 1
 100       };
 101     PB_DS_STATIC_ASSERT(min_max_size, max_size >= 2);
 102
 103     /// Returns a const_iterator to the first element of
 104     /// key_const_reference agumnet.
 105     inline static const_iterator
 106     begin(key_const_reference);
 107
 108     /// Returns a const_iterator to the after-last element of
 109     /// key_const_reference argument.
 110     inline static const_iterator
 111     end(key_const_reference);
 112
 113     /// Maps an element to a position.
 114     inline static size_type
 115     e_pos(e_type e);
 116
 117   private:
 118     inline static const_iterator
 119     begin_imp(key_const_reference, detail::false_type);
 120
 121     inline static const_iterator
 122     begin_imp(key_const_reference, detail::true_type);
 123
 124     inline static const_iterator
 125     end_imp(key_const_reference, detail::false_type);
 126
 127     inline static const_iterator
 128     end_imp(key_const_reference, detail::true_type);
 129
 130     static detail::integral_constant<int, Reverse> s_rev_ind;
 131   };
 132
 133 #include <ext/pb_ds/detail/trie_policy/trie_string_access_traits_imp.hpp>
 134
 135 #undef PB_DS_CLASS_T_DEC
 136 #undef PB_DS_CLASS_C_DEC
 137
 138 #define PB_DS_CLASS_T_DEC \
 139   template<typename Node_CItr,typename Node_Itr, \
 140            typename _ATraits, typename _Alloc>
 141
 142 #define PB_DS_CLASS_C_DEC \
 143   trie_prefix_search_node_update<Node_CItr, Node_Itr, \
 144                                  _ATraits,_Alloc>
 145
 146 #define PB_DS_TRIE_POLICY_BASE \
 147   detail::trie_policy_base<Node_CItr,Node_Itr,_ATraits, _Alloc>
 148
 149   /// A node updator that allows tries to be searched for the range of
 150   /// values that match a certain prefix.
 151   template<typename Node_CItr,
 152            typename Node_Itr,
 153            typename _ATraits,
 154            typename _Alloc>
 155   class trie_prefix_search_node_update : private PB_DS_TRIE_POLICY_BASE
 156   {
 157   private:
 158     typedef PB_DS_TRIE_POLICY_BASE                      base_type;
 159
 160   public:
 161     typedef typename base_type::key_type                key_type;
 162     typedef typename base_type::key_const_reference     key_const_reference;
 163
 164     /// Element access traits.
 165     typedef _ATraits                            access_traits;
 166
 167     /// Const element iterator.
 168     typedef typename access_traits::const_iterator      a_const_iterator;
 169
 170     /// _Alloc type.
 171     typedef _Alloc                                      allocator_type;
 172
 173     /// Size type.
 174     typedef typename allocator_type::size_type          size_type;
 175     typedef null_type                                   metadata_type;
 176     typedef Node_Itr                                    node_iterator;
 177     typedef Node_CItr                                   node_const_iterator;
 178     typedef typename node_iterator::value_type          iterator;
 179     typedef typename node_const_iterator::value_type    const_iterator;
 180
 181     /// Finds the const iterator range corresponding to all values
 182     /// whose prefixes match r_key.
 183     std::pair<const_iterator, const_iterator>
 184     prefix_range(key_const_reference) const;
 185
 186     /// Finds the iterator range corresponding to all values whose
 187     /// prefixes match r_key.
 188     std::pair<iterator, iterator>
 189     prefix_range(key_const_reference);
 190
 191     /// Finds the const iterator range corresponding to all values
 192     /// whose prefixes match [b, e).
 193     std::pair<const_iterator, const_iterator>
 194     prefix_range(a_const_iterator, a_const_iterator) const;
 195
 196     /// Finds the iterator range corresponding to all values whose
 197     /// prefixes match [b, e).
 198     std::pair<iterator, iterator>
 199     prefix_range(a_const_iterator, a_const_iterator);
 200
 201   protected:
 202     /// Called to update a node's metadata.
 203     inline void
 204     operator()(node_iterator node_it, node_const_iterator end_nd_it) const;
 205
 206   private:
 207     node_iterator
 208     next_child(node_iterator, a_const_iterator, a_const_iterator,
 209                node_iterator, const access_traits&);
 210
 211     /// Returns the const iterator associated with the just-after last element.
 212     virtual const_iterator
 213     end() const = 0;
 214
 215     /// Returns the iterator associated with the just-after last element.
 216     virtual iterator
 217     end() = 0;
 218
 219     /// Returns the node_const_iterator associated with the trie's root node.
 220     virtual node_const_iterator
 221     node_begin() const = 0;
 222
 223     /// Returns the node_iterator associated with the trie's root node.
 224     virtual node_iterator
 225     node_begin() = 0;
 226
 227     /// Returns the node_const_iterator associated with a just-after leaf node.
 228     virtual node_const_iterator
 229     node_end() const = 0;
 230
 231     /// Returns the node_iterator associated with a just-after leaf node.
 232     virtual node_iterator
 233     node_end() = 0;
 234
 235     /// Access to the cmp_fn object.
 236     virtual const access_traits&
 237     get_access_traits() const = 0;
 238   };
 239
 240 #include <ext/pb_ds/detail/trie_policy/prefix_search_node_update_imp.hpp>
 241
 242 #undef PB_DS_CLASS_C_DEC
 243
 244 #define PB_DS_CLASS_C_DEC \
 245   trie_order_statistics_node_update<Node_CItr, Node_Itr, \
 246                                     _ATraits, _Alloc>
 247
 248   /// Functor updating ranks of entrees.
 249   template<typename Node_CItr,
 250            typename Node_Itr,
 251            typename _ATraits,
 252            typename _Alloc>
 253   class trie_order_statistics_node_update : private PB_DS_TRIE_POLICY_BASE
 254   {
 255   private:
 256     typedef PB_DS_TRIE_POLICY_BASE                      base_type;
 257
 258   public:
 259     typedef _ATraits                            access_traits;
 260     typedef typename access_traits::const_iterator      a_const_iterator;
 261     typedef _Alloc                                      allocator_type;
 262     typedef typename allocator_type::size_type          size_type;
 263     typedef typename base_type::key_type                key_type;
 264     typedef typename base_type::key_const_reference     key_const_reference;
 265
 266     typedef size_type                                   metadata_type;
 267     typedef Node_CItr                                   node_const_iterator;
 268     typedef Node_Itr                                    node_iterator;
 269     typedef typename node_const_iterator::value_type    const_iterator;
 270     typedef typename node_iterator::value_type          iterator;
 271
 272     /// Finds an entry by __order. Returns a const_iterator to the
 273     /// entry with the __order order, or a const_iterator to the
 274     /// container object's end if order is at least the size of the
 275     /// container object.
 276     inline const_iterator
 277     find_by_order(size_type) const;
 278
 279     /// Finds an entry by __order. Returns an iterator to the entry
 280     /// with the __order order, or an iterator to the container
 281     /// object's end if order is at least the size of the container
 282     /// object.
 283     inline iterator
 284     find_by_order(size_type);
 285
 286     /// Returns the order of a key within a sequence. For exapmle, if
 287     /// r_key is the smallest key, this method will return 0; if r_key
 288     /// is a key between the smallest and next key, this method will
 289     /// return 1; if r_key is a key larger than the largest key, this
 290     /// method will return the size of r_c.
 291     inline size_type
 292     order_of_key(key_const_reference) const;
 293
 294     /// Returns the order of a prefix within a sequence. For exapmle,
 295     /// if [b, e] is the smallest prefix, this method will return 0; if
 296     /// r_key is a key between the smallest and next key, this method
 297     /// will return 1; if r_key is a key larger than the largest key,
 298     /// this method will return the size of r_c.
 299     inline size_type
 300     order_of_prefix(a_const_iterator, a_const_iterator) const;
 301
 302   protected:
 303     /// Updates the rank of a node through a node_iterator node_it;
 304     /// end_nd_it is the end node iterator.
 305     inline void
 306     operator()(node_iterator, node_const_iterator) const;
 307
 308   private:
 309     typedef typename base_type::const_reference         const_reference;
 310     typedef typename base_type::const_pointer           const_pointer;
 311
 312     typedef typename _Alloc::template rebind<metadata_type> __rebind_m;
 313     typedef typename __rebind_m::other                  __rebind_ma;
 314     typedef typename __rebind_ma::const_reference      metadata_const_reference;
 315     typedef typename __rebind_ma::reference             metadata_reference;
 316
 317     /// Returns true if the container is empty.
 318     _GLIBCXX_NODISCARD virtual bool
 319     empty() const = 0;
 320
 321     /// Returns the iterator associated with the trie's first element.
 322     virtual iterator
 323     begin() = 0;
 324
 325     /// Returns the iterator associated with the trie's
 326     /// just-after-last element.
 327     virtual iterator
 328     end() = 0;
 329
 330     /// Returns the node_const_iterator associated with the trie's root node.
 331     virtual node_const_iterator
 332     node_begin() const = 0;
 333
 334     /// Returns the node_iterator associated with the trie's root node.
 335     virtual node_iterator
 336     node_begin() = 0;
 337
 338     /// Returns the node_const_iterator associated with a just-after
 339     /// leaf node.
 340     virtual node_const_iterator
 341     node_end() const = 0;
 342
 343     /// Returns the node_iterator associated with a just-after leaf node.
 344     virtual node_iterator
 345     node_end() = 0;
 346
 347     /// Access to the cmp_fn object.
 348     virtual access_traits&
 349     get_access_traits() = 0;
 350   };
 351
 352 #include <ext/pb_ds/detail/trie_policy/order_statistics_imp.hpp>
 353
 354 #undef PB_DS_CLASS_T_DEC
 355 #undef PB_DS_CLASS_C_DEC
 356 #undef PB_DS_TRIE_POLICY_BASE
 357
 358 } // namespace __gnu_pbds
 359
 360 #endif