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

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2007, 2009, 2010, 2011
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the terms
   8 // of the GNU General Public License as published by the Free Software
   9 // Foundation; either version 3, or (at your option) any later
  10 // version.
  11
  12 // This library is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16
  17 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  27
  28 // Permission to use, copy, modify, sell, and distribute this software
  29 // is hereby granted without fee, provided that the above copyright
  30 // notice appears in all copies, and that both that copyright notice
  31 // and this permission notice appear in supporting documentation. None
  32 // of the above authors, nor IBM Haifa Research Laboratories, make any
  33 // representation about the suitability of this software for any
  34 // purpose. It is provided "as is" without express or implied
  35 // warranty.
  36
  37 /**
  38  * @file trie_policy.hpp
  39  * Contains trie-related policies.
  40  */
  41
  42 #ifndef PB_DS_TRIE_POLICY_HPP
  43 #define PB_DS_TRIE_POLICY_HPP
  44
  45 #include <bits/c++config.h>
  46 #include <string>
  47 #include <ext/pb_ds/detail/type_utils.hpp>
  48 #include <ext/pb_ds/detail/trie_policy/trie_policy_base.hpp>
  49
  50 namespace __gnu_pbds
  51 {
  52 #define PB_DS_CLASS_T_DEC \
  53   template<typename String, typename String::value_type Min_E_Val, \
  54            typename String::value_type Max_E_Val, bool Reverse, \
  55            typename _Alloc>
  56
  57 #define PB_DS_CLASS_C_DEC \
  58   trie_string_access_traits<String, Min_E_Val,Max_E_Val,Reverse,_Alloc>
  59
  60   /**
  61    *  Element access traits for string types.
  62    *
  63    *  @tparam String            String type.
  64    *  @tparam Min_E_Val         Minimal element value.
  65    *  @tparam Max_E_Val         Maximum element value.
  66    *  @tparam Reverse           Reverse iteration should be used.
  67    *                            Default: false.
  68    *  @tparam _Alloc            Allocator type.
  69    */
  70   template<typename String = std::string,
  71            typename String::value_type Min_E_Val = detail::__numeric_traits<typename String::value_type>::__min,
  72            typename String::value_type Max_E_Val = detail::__numeric_traits<typename String::value_type>::__max,
  73            bool Reverse = false,
  74            typename _Alloc = std::allocator<char> >
  75   struct trie_string_access_traits
  76   {
  77   public:
  78     typedef typename _Alloc::size_type                    size_type;
  79     typedef String                                        key_type;
  80     typedef typename _Alloc::template rebind<key_type>    __rebind_k;
  81     typedef typename __rebind_k::other::const_reference   key_const_reference;
  82
  83     enum
  84       {
  85         reverse = Reverse
  86       };
  87
  88     /// Element const iterator type.
  89     typedef typename detail::__conditional_type<Reverse, \
  90                        typename String::const_reverse_iterator, \
  91                        typename String::const_iterator>::__type const_iterator;
  92
  93     /// Element type.
  94     typedef typename std::iterator_traits<const_iterator>::value_type e_type;
  95
  96     enum
  97       {
  98         min_e_val = Min_E_Val,
  99         max_e_val = Max_E_Val,
 100         max_size = max_e_val - min_e_val + 1
 101       };
 102     PB_DS_STATIC_ASSERT(min_max_size, max_size >= 2);
 103
 104     /// Returns a const_iterator to the first element of
 105     /// key_const_reference agumnet.
 106     inline static const_iterator
 107     begin(key_const_reference);
 108
 109     /// Returns a const_iterator to the after-last element of
 110     /// key_const_reference argument.
 111     inline static const_iterator
 112     end(key_const_reference);
 113
 114     /// Maps an element to a position.
 115     inline static size_type
 116     e_pos(e_type e);
 117
 118   private:
 119     inline static const_iterator
 120     begin_imp(key_const_reference, detail::false_type);
 121
 122     inline static const_iterator
 123     begin_imp(key_const_reference, detail::true_type);
 124
 125     inline static const_iterator
 126     end_imp(key_const_reference, detail::false_type);
 127
 128     inline static const_iterator
 129     end_imp(key_const_reference, detail::true_type);
 130
 131     static detail::integral_constant<int, Reverse> s_rev_ind;
 132   };
 133
 134 #include <ext/pb_ds/detail/trie_policy/trie_string_access_traits_imp.hpp>
 135
 136 #undef PB_DS_CLASS_T_DEC
 137 #undef PB_DS_CLASS_C_DEC
 138
 139 #define PB_DS_CLASS_T_DEC \
 140   template<typename Node_CItr,typename Node_Itr, \
 141            typename _ATraits, typename _Alloc>
 142
 143 #define PB_DS_CLASS_C_DEC \
 144   trie_prefix_search_node_update<Node_CItr, Node_Itr, \
 145                                  _ATraits,_Alloc>
 146
 147 #define PB_DS_TRIE_POLICY_BASE \
 148   detail::trie_policy_base<Node_CItr,Node_Itr,_ATraits, _Alloc>
 149
 150   /// A node updator that allows tries to be searched for the range of
 151   /// values that match a certain prefix.
 152   template<typename Node_CItr,
 153            typename Node_Itr,
 154            typename _ATraits,
 155            typename _Alloc>
 156   class trie_prefix_search_node_update : private PB_DS_TRIE_POLICY_BASE
 157   {
 158   private:
 159     typedef PB_DS_TRIE_POLICY_BASE                      base_type;
 160
 161   public:
 162     typedef typename base_type::key_type                key_type;
 163     typedef typename base_type::key_const_reference     key_const_reference;
 164
 165     /// Element access traits.
 166     typedef _ATraits                            access_traits;
 167
 168     /// Const element iterator.
 169     typedef typename access_traits::const_iterator      a_const_iterator;
 170
 171     /// _Alloc type.
 172     typedef _Alloc                                      allocator_type;
 173
 174     /// Size type.
 175     typedef typename allocator_type::size_type          size_type;
 176     typedef null_type                                   metadata_type;
 177     typedef Node_Itr                                    node_iterator;
 178     typedef Node_CItr                                   node_const_iterator;
 179     typedef typename node_iterator::value_type          iterator;
 180     typedef typename node_const_iterator::value_type    const_iterator;
 181
 182     /// Finds the const iterator range corresponding to all values
 183     /// whose prefixes match r_key.
 184     std::pair<const_iterator, const_iterator>
 185     prefix_range(key_const_reference) const;
 186
 187     /// Finds the iterator range corresponding to all values whose
 188     /// prefixes match r_key.
 189     std::pair<iterator, iterator>
 190     prefix_range(key_const_reference);
 191
 192     /// Finds the const iterator range corresponding to all values
 193     /// whose prefixes match [b, e).
 194     std::pair<const_iterator, const_iterator>
 195     prefix_range(a_const_iterator, a_const_iterator) const;
 196
 197     /// Finds the iterator range corresponding to all values whose
 198     /// prefixes match [b, e).
 199     std::pair<iterator, iterator>
 200     prefix_range(a_const_iterator, a_const_iterator);
 201
 202   protected:
 203     /// Called to update a node's metadata.
 204     inline void
 205     operator()(node_iterator node_it, node_const_iterator end_nd_it) const;
 206
 207   private:
 208     node_iterator
 209     next_child(node_iterator, a_const_iterator, a_const_iterator,
 210                node_iterator, const access_traits&);
 211
 212     /// Returns the const iterator associated with the just-after last element.
 213     virtual const_iterator
 214     end() const = 0;
 215
 216     /// Returns the iterator associated with the just-after last element.
 217     virtual iterator
 218     end() = 0;
 219
 220     /// Returns the node_const_iterator associated with the trie's root node.
 221     virtual node_const_iterator
 222     node_begin() const = 0;
 223
 224     /// Returns the node_iterator associated with the trie's root node.
 225     virtual node_iterator
 226     node_begin() = 0;
 227
 228     /// Returns the node_const_iterator associated with a just-after leaf node.
 229     virtual node_const_iterator
 230     node_end() const = 0;
 231
 232     /// Returns the node_iterator associated with a just-after leaf node.
 233     virtual node_iterator
 234     node_end() = 0;
 235
 236     /// Access to the cmp_fn object.
 237     virtual const access_traits&
 238     get_access_traits() const = 0;
 239   };
 240
 241 #include <ext/pb_ds/detail/trie_policy/prefix_search_node_update_imp.hpp>
 242
 243 #undef PB_DS_CLASS_C_DEC
 244
 245 #define PB_DS_CLASS_C_DEC \
 246   trie_order_statistics_node_update<Node_CItr, Node_Itr, \
 247                                     _ATraits, _Alloc>
 248
 249   /// Functor updating ranks of entrees.
 250   template<typename Node_CItr,
 251            typename Node_Itr,
 252            typename _ATraits,
 253            typename _Alloc>
 254   class trie_order_statistics_node_update : private PB_DS_TRIE_POLICY_BASE
 255   {
 256   private:
 257     typedef PB_DS_TRIE_POLICY_BASE                      base_type;
 258
 259   public:
 260     typedef _ATraits                            access_traits;
 261     typedef typename access_traits::const_iterator      a_const_iterator;
 262     typedef _Alloc                                      allocator_type;
 263     typedef typename allocator_type::size_type          size_type;
 264     typedef typename base_type::key_type                key_type;
 265     typedef typename base_type::key_const_reference     key_const_reference;
 266
 267     typedef size_type                                   metadata_type;
 268     typedef Node_CItr                                   node_const_iterator;
 269     typedef Node_Itr                                    node_iterator;
 270     typedef typename node_const_iterator::value_type    const_iterator;
 271     typedef typename node_iterator::value_type          iterator;
 272
 273     /// Finds an entry by __order. Returns a const_iterator to the
 274     /// entry with the __order order, or a const_iterator to the
 275     /// container object's end if order is at least the size of the
 276     /// container object.
 277     inline const_iterator
 278     find_by_order(size_type) const;
 279
 280     /// Finds an entry by __order. Returns an iterator to the entry
 281     /// with the __order order, or an iterator to the container
 282     /// object's end if order is at least the size of the container
 283     /// object.
 284     inline iterator
 285     find_by_order(size_type);
 286
 287     /// Returns the order of a key within a sequence. For exapmle, if
 288     /// r_key is the smallest key, this method will return 0; if r_key
 289     /// is a key between the smallest and next key, this method will
 290     /// return 1; if r_key is a key larger than the largest key, this
 291     /// method will return the size of r_c.
 292     inline size_type
 293     order_of_key(key_const_reference) const;
 294
 295     /// Returns the order of a prefix within a sequence. For exapmle,
 296     /// if [b, e] is the smallest prefix, this method will return 0; if
 297     /// r_key is a key between the smallest and next key, this method
 298     /// will return 1; if r_key is a key larger than the largest key,
 299     /// this method will return the size of r_c.
 300     inline size_type
 301     order_of_prefix(a_const_iterator, a_const_iterator) const;
 302
 303   protected:
 304     /// Updates the rank of a node through a node_iterator node_it;
 305     /// end_nd_it is the end node iterator.
 306     inline void
 307     operator()(node_iterator, node_const_iterator) const;
 308
 309   private:
 310     typedef typename base_type::const_reference         const_reference;
 311     typedef typename base_type::const_pointer           const_pointer;
 312
 313     typedef typename _Alloc::template rebind<metadata_type> __rebind_m;
 314     typedef typename __rebind_m::other                  __rebind_ma;
 315     typedef typename __rebind_ma::const_reference      metadata_const_reference;
 316     typedef typename __rebind_ma::reference             metadata_reference;
 317
 318     /// Returns true if the container is empty.
 319     virtual bool
 320     empty() const = 0;
 321
 322     /// Returns the iterator associated with the trie's first element.
 323     virtual iterator
 324     begin() = 0;
 325
 326     /// Returns the iterator associated with the trie's
 327     /// just-after-last element.
 328     virtual iterator
 329     end() = 0;
 330
 331     /// Returns the node_const_iterator associated with the trie's root node.
 332     virtual node_const_iterator
 333     node_begin() const = 0;
 334
 335     /// Returns the node_iterator associated with the trie's root node.
 336     virtual node_iterator
 337     node_begin() = 0;
 338
 339     /// Returns the node_const_iterator associated with a just-after
 340     /// leaf node.
 341     virtual node_const_iterator
 342     node_end() const = 0;
 343
 344     /// Returns the node_iterator associated with a just-after leaf node.
 345     virtual node_iterator
 346     node_end() = 0;
 347
 348     /// Access to the cmp_fn object.
 349     virtual access_traits&
 350     get_access_traits() = 0;
 351   };
 352
 353 #include <ext/pb_ds/detail/trie_policy/order_statistics_imp.hpp>
 354
 355 #undef PB_DS_CLASS_T_DEC
 356 #undef PB_DS_CLASS_C_DEC
 357 #undef PB_DS_TRIE_POLICY_BASE
 358
 359 } // namespace __gnu_pbds
 360
 361 #endif