1 // -*- C++ -*- 2 3 // Copyright (C) 2005, 2006, 2007, 2009 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 <string> 45 #include <ext/pb_ds/detail/type_utils.hpp> 46 #include <ext/pb_ds/detail/trie_policy/trie_policy_base.hpp> 47 48 namespace __gnu_pbds 49 { 50 // A null node updator, indicating that no node updates are required. 51 template<typename Const_Node_Iterator, 52 typename Node_Iterator, 53 typename E_Access_Traits, 54 typename Allocator> 55 struct null_trie_node_update 56 { }; 57 58 #define PB_DS_CLASS_T_DEC \ 59 template<typename String, typename String::value_type Min_E_Val, typename String::value_type Max_E_Val, bool Reverse, typename Allocator> 60 61 #define PB_DS_CLASS_C_DEC \ 62 string_trie_e_access_traits<String, Min_E_Val,Max_E_Val,Reverse,Allocator> 63 64 // Element access traits for string types. 65 template<typename String = std::string, 66 typename String::value_type Min_E_Val = detail::__numeric_traits<typename String::value_type>::__min, 67 typename String::value_type Max_E_Val = detail::__numeric_traits<typename String::value_type>::__max, 68 bool Reverse = false, 69 typename Allocator = std::allocator<char> > 70 struct string_trie_e_access_traits 71 { 72 public: 73 typedef typename Allocator::size_type size_type; 74 typedef String key_type; 75 typedef typename Allocator::template rebind<key_type>::other key_rebind; 76 typedef typename key_rebind::const_reference const_key_reference; 77 78 enum 79 { 80 reverse = Reverse 81 }; 82 83 // Element const iterator type. 84 typedef typename detail::__conditional_type<Reverse, typename String::const_reverse_iterator, typename String::const_iterator>::__type const_iterator; 85 86 // Element type. 87 typedef typename std::iterator_traits<const_iterator>::value_type e_type; 88 89 enum 90 { 91 min_e_val = Min_E_Val, 92 max_e_val = Max_E_Val, 93 max_size = max_e_val - min_e_val + 1 94 }; 95 PB_DS_STATIC_ASSERT(min_max_size, max_size >= 2); 96 97 // Returns a const_iterator to the first element of 98 // const_key_reference agumnet. 99 inline static const_iterator 100 begin(const_key_reference); 101 102 // Returns a const_iterator to the after-last element of 103 // const_key_reference argument. 104 inline static const_iterator 105 end(const_key_reference); 106 107 // Maps an element to a position. 108 inline static size_type 109 e_pos(e_type e); 110 111 private: 112 113 inline static const_iterator 114 begin_imp(const_key_reference, detail::false_type); 115 116 inline static const_iterator 117 begin_imp(const_key_reference, detail::true_type); 118 119 inline static const_iterator 120 end_imp(const_key_reference, detail::false_type); 121 122 inline static const_iterator 123 end_imp(const_key_reference, detail::true_type); 124 125 static detail::integral_constant<int, Reverse> s_rev_ind; 126 }; 127 128 #include <ext/pb_ds/detail/trie_policy/string_trie_e_access_traits_imp.hpp> 129 130 #undef PB_DS_CLASS_T_DEC 131 #undef PB_DS_CLASS_C_DEC 132 133 #define PB_DS_CLASS_T_DEC \ 134 template<typename Const_Node_Iterator,typename Node_Iterator,class E_Access_Traits, typename Allocator> 135 136 #define PB_DS_CLASS_C_DEC \ 137 trie_prefix_search_node_update<Const_Node_Iterator, Node_Iterator, E_Access_Traits,Allocator> 138 139 #define PB_DS_BASE_C_DEC \ 140 detail::trie_policy_base<Const_Node_Iterator,Node_Iterator,E_Access_Traits, Allocator> 141 142 // A node updator that allows tries to be searched for the range of 143 // values that match a certain prefix. 144 template<typename Const_Node_Iterator, 145 typename Node_Iterator, 146 typename E_Access_Traits, 147 typename Allocator> 148 class trie_prefix_search_node_update : private PB_DS_BASE_C_DEC 149 { 150 private: 151 typedef PB_DS_BASE_C_DEC base_type; 152 153 public: 154 typedef typename base_type::key_type key_type; 155 typedef typename base_type::const_key_reference const_key_reference; 156 157 // Element access traits. 158 typedef E_Access_Traits e_access_traits; 159 160 // Const element iterator. 161 typedef typename e_access_traits::const_iterator const_e_iterator; 162 163 // Allocator type. 164 typedef Allocator allocator_type; 165 166 // Size type. 167 typedef typename allocator_type::size_type size_type; 168 typedef detail::null_node_metadata metadata_type; 169 typedef Const_Node_Iterator const_node_iterator; 170 typedef Node_Iterator node_iterator; 171 typedef typename const_node_iterator::value_type const_iterator; 172 typedef typename node_iterator::value_type iterator; 173 174 // Finds the const iterator range corresponding to all values 175 // whose prefixes match r_key. 176 std::pair<const_iterator, const_iterator> 177 prefix_range(const_key_reference) const; 178 179 // Finds the iterator range corresponding to all values whose 180 // prefixes match r_key. 181 std::pair<iterator, iterator> 182 prefix_range(const_key_reference); 183 184 // Finds the const iterator range corresponding to all values 185 // whose prefixes match [b, e). 186 std::pair<const_iterator, const_iterator> 187 prefix_range(const_e_iterator, const_e_iterator) const; 188 189 // Finds the iterator range corresponding to all values whose 190 // prefixes match [b, e). 191 std::pair<iterator, iterator> 192 prefix_range(const_e_iterator, const_e_iterator); 193 194 protected: 195 // Called to update a node's metadata. 196 inline void 197 operator()(node_iterator node_it, const_node_iterator end_nd_it) const; 198 199 private: 200 // Returns the const iterator associated with the just-after last element. 201 virtual const_iterator 202 end() const = 0; 203 204 // Returns the iterator associated with the just-after last element. 205 virtual iterator 206 end() = 0; 207 208 // Returns the const_node_iterator associated with the trie's root node. 209 virtual const_node_iterator 210 node_begin() const = 0; 211 212 // Returns the node_iterator associated with the trie's root node. 213 virtual node_iterator 214 node_begin() = 0; 215 216 // Returns the const_node_iterator associated with a just-after leaf node. 217 virtual const_node_iterator 218 node_end() const = 0; 219 220 // Returns the node_iterator associated with a just-after leaf node. 221 virtual node_iterator 222 node_end() = 0; 223 224 // Access to the cmp_fn object. 225 virtual const e_access_traits& 226 get_e_access_traits() const = 0; 227 228 node_iterator 229 next_child(node_iterator, const_e_iterator, const_e_iterator, 230 node_iterator, const e_access_traits&); 231 }; 232 233 #include <ext/pb_ds/detail/trie_policy/prefix_search_node_update_imp.hpp> 234 235 #undef PB_DS_CLASS_C_DEC 236 237 #define PB_DS_CLASS_C_DEC \ 238 trie_order_statistics_node_update<Const_Node_Iterator, Node_Iterator,E_Access_Traits, Allocator> 239 240 // Functor updating ranks of entrees. 241 template<typename Const_Node_Iterator, 242 typename Node_Iterator, 243 typename E_Access_Traits, 244 typename Allocator> 245 class trie_order_statistics_node_update : private PB_DS_BASE_C_DEC 246 { 247 private: 248 typedef PB_DS_BASE_C_DEC base_type; 249 250 public: 251 typedef E_Access_Traits e_access_traits; 252 typedef typename e_access_traits::const_iterator const_e_iterator; 253 typedef Allocator allocator_type; 254 typedef typename allocator_type::size_type size_type; 255 typedef typename base_type::key_type key_type; 256 typedef typename base_type::const_key_reference const_key_reference; 257 258 typedef size_type metadata_type; 259 typedef Const_Node_Iterator const_node_iterator; 260 typedef Node_Iterator node_iterator; 261 typedef typename const_node_iterator::value_type const_iterator; 262 typedef typename node_iterator::value_type iterator; 263 264 // Finds an entry by __order. Returns a const_iterator to the 265 // entry with the __order order, or a const_iterator to the 266 // container object's end if order is at least the size of the 267 // container object. 268 inline const_iterator 269 find_by_order(size_type) const; 270 271 // Finds an entry by __order. Returns an iterator to the entry 272 // with the __order order, or an iterator to the container 273 // object's end if order is at least the size of the container 274 // object. 275 inline iterator 276 find_by_order(size_type); 277 278 // Returns the order of a key within a sequence. For exapmle, if 279 // r_key is the smallest key, this method will return 0; if r_key 280 // is a key between the smallest and next key, this method will 281 // return 1; if r_key is a key larger than the largest key, this 282 // method will return the size of r_c. 283 inline size_type 284 order_of_key(const_key_reference) const; 285 286 // Returns the order of a prefix within a sequence. For exapmle, 287 // if [b, e] is the smallest prefix, this method will return 0; if 288 // r_key is a key between the smallest and next key, this method 289 // will return 1; if r_key is a key larger than the largest key, 290 // this method will return the size of r_c. 291 inline size_type 292 order_of_prefix(const_e_iterator, const_e_iterator) const; 293 294 private: 295 typedef typename base_type::const_reference const_reference; 296 typedef typename base_type::const_pointer const_pointer; 297 298 typedef typename Allocator::template rebind<metadata_type>::other metadata_rebind; 299 typedef typename metadata_rebind::const_reference const_metadata_reference; 300 typedef typename metadata_rebind::reference metadata_reference; 301 302 // Returns true if the container is empty. 303 virtual bool 304 empty() const = 0; 305 306 // Returns the iterator associated with the trie's first element. 307 virtual iterator 308 begin() = 0; 309 310 // Returns the iterator associated with the trie's 311 // just-after-last element. 312 virtual iterator 313 end() = 0; 314 315 // Returns the const_node_iterator associated with the trie's root node. 316 virtual const_node_iterator 317 node_begin() const = 0; 318 319 // Returns the node_iterator associated with the trie's root node. 320 virtual node_iterator 321 node_begin() = 0; 322 323 // Returns the const_node_iterator associated with a just-after 324 // leaf node. 325 virtual const_node_iterator 326 node_end() const = 0; 327 328 // Returns the node_iterator associated with a just-after leaf node. 329 virtual node_iterator 330 node_end() = 0; 331 332 // Access to the cmp_fn object. 333 virtual e_access_traits& 334 get_e_access_traits() = 0; 335 336 protected: 337 // Updates the rank of a node through a node_iterator node_it; 338 // end_nd_it is the end node iterator. 339 inline void 340 operator()(node_iterator, const_node_iterator) const; 341 342 // Destructor. 343 virtual 344 ~trie_order_statistics_node_update(); 345 }; 346 347 #include <ext/pb_ds/detail/trie_policy/order_statistics_imp.hpp> 348 349 #undef PB_DS_CLASS_T_DEC 350 #undef PB_DS_CLASS_C_DEC 351 #undef PB_DS_BASE_C_DEC 352 353 } // namespace __gnu_pbds 354 355 #endif 356