pat_trie_.hpp

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// -*- C++ -*-
 
// Copyright (C) 2005-2026 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 pat_trie_/pat_trie_.hpp
 * Contains an implementation class for a patricia tree.
 */
 
#include <iterator>
#include <utility>
#include <algorithm>
#include <functional>
#include <assert.h>
#include <list>
#include <ext/pb_ds/exception.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/cond_dealtor.hpp>
#include <ext/pb_ds/detail/type_utils.hpp>
#include <ext/pb_ds/detail/types_traits.hpp>
#include <ext/pb_ds/detail/eq_fn/eq_by_less.hpp>
#include <ext/pb_ds/detail/pat_trie_/synth_access_traits.hpp>
#include <ext/pb_ds/detail/pat_trie_/pat_trie_base.hpp>
#ifdef _GLIBCXX_DEBUG
#include <ext/pb_ds/detail/debug_map_base.hpp>
#endif
#include <debug/debug.h>
 
namespace __gnu_pbds
{
  namespace detail
  {
#ifdef PB_DS_DATA_TRUE_INDICATOR
#define PB_DS_PAT_TRIE_NAME pat_trie_map
#endif
 
#ifdef PB_DS_DATA_FALSE_INDICATOR
#define PB_DS_PAT_TRIE_NAME pat_trie_set
#endif
 
#define PB_DS_CLASS_T_DEC \
    template<typename Key, typename Mapped, typename Node_And_It_Traits, \
           typename _Alloc>
 
#define PB_DS_CLASS_C_DEC \
    PB_DS_PAT_TRIE_NAME<Key, Mapped, Node_And_It_Traits, _Alloc>
 
#define PB_DS_PAT_TRIE_TRAITS_BASE \
    types_traits<Key, Mapped, _Alloc, false>
 
#ifdef _GLIBCXX_DEBUG
#define PB_DS_DEBUG_MAP_BASE_C_DEC \
    debug_map_base<Key, eq_by_less<Key, std::less<Key> >, \
             typename rebind_traits<_Alloc, Key>::const_reference>
#endif
 
 
    /**
     *  @brief PATRICIA trie.
     *  @ingroup branch-detail
     *
     *  This implementation loosely borrows ideas from:
     *  1) Fast Mergeable Integer Maps, Okasaki, Gill 1998
     *  2) Ptset: Sets of integers implemented as Patricia trees,
     *     Jean-Christophe Filliatr, 2000
     */
    template<typename Key, typename Mapped, typename Node_And_It_Traits,
           typename _Alloc>
    class PB_DS_PAT_TRIE_NAME :
#ifdef _GLIBCXX_DEBUG
      public PB_DS_DEBUG_MAP_BASE_C_DEC,
#endif
      public Node_And_It_Traits::synth_access_traits,
      public Node_And_It_Traits::node_update,
      public PB_DS_PAT_TRIE_TRAITS_BASE,
      public pat_trie_base
    {
    private:
      typedef pat_trie_base                     base_type;
      typedef PB_DS_PAT_TRIE_TRAITS_BASE        traits_base;
      typedef Node_And_It_Traits                traits_type;
 
      typedef typename traits_type::synth_access_traits synth_access_traits;
      typedef typename synth_access_traits::const_iterator a_const_iterator;
 
      typedef typename traits_type::node        node;
      typedef rebind_traits<_Alloc, node>       __rebind_n;
      typedef typename __rebind_n::const_pointer      node_const_pointer;
      typedef typename __rebind_n::pointer            node_pointer;
 
      typedef typename traits_type::head        head;
      typedef rebind_traits<_Alloc, head>       __rebind_h;
      typedef typename __rebind_h::allocator_type     head_allocator;
      typedef typename __rebind_h::pointer            head_pointer;
 
      typedef typename traits_type::leaf        leaf;
      typedef rebind_traits<_Alloc, leaf>       __rebind_l;
      typedef typename __rebind_l::allocator_type     leaf_allocator;
      typedef typename __rebind_l::pointer            leaf_pointer;
      typedef typename __rebind_l::const_pointer      leaf_const_pointer;
 
      typedef typename traits_type::inode       inode;
      typedef typename inode::iterator                inode_iterator;
      typedef rebind_traits<_Alloc, inode>            __rebind_in;
      typedef typename __rebind_in::allocator_type    inode_allocator;
      typedef typename __rebind_in::pointer           inode_pointer;
      typedef typename __rebind_in::const_pointer     inode_const_pointer;
 
 
      /// Conditional deallocator.
      class cond_dealtor
      {
      protected:
      leaf_pointer            m_p_nd;
      bool              m_no_action_dtor;
      bool              m_call_destructor;
 
      public:
      cond_dealtor(leaf_pointer p_nd)
      : m_p_nd(p_nd), m_no_action_dtor(false), m_call_destructor(false)
      { }
 
      void
      set_no_action_dtor()
      { m_no_action_dtor = true; }
 
      void
      set_call_destructor()
      { m_call_destructor = true; }
 
      ~cond_dealtor()
      {
        if (m_no_action_dtor)
          return;
 
        if (m_call_destructor)
          m_p_nd->~leaf();
 
        s_leaf_allocator.deallocate(m_p_nd, 1);
      }
      };
 
 
      /// Branch bag, for split-join.
      class branch_bag
      {
      private:
      typedef inode_pointer                           __inp;
      typedef typename rebind_traits<_Alloc, __inp>::allocator_type
        __rebind_inp;
 
#ifdef _GLIBCXX_DEBUG
      typedef std::_GLIBCXX_STD_C::list<__inp, __rebind_inp>      bag_type;
#else
      typedef std::list<__inp, __rebind_inp>                bag_type;
#endif
 
      bag_type                                  m_bag;
      public:
      void
      add_branch()
      {
        inode_pointer p_nd = s_inode_allocator.allocate(1);
        __try
          {
            m_bag.push_back(p_nd);
          }
        __catch(...)
          {
            s_inode_allocator.deallocate(p_nd, 1);
            __throw_exception_again;
          }
      }
 
      inode_pointer
      get_branch()
      {
        _GLIBCXX_DEBUG_ASSERT(!m_bag.empty());
        inode_pointer p_nd = *m_bag.begin();
        m_bag.pop_front();
        return p_nd;
      }
 
      ~branch_bag()
      {
        while (!m_bag.empty())
          {
            inode_pointer p_nd = *m_bag.begin();
            s_inode_allocator.deallocate(p_nd, 1);
            m_bag.pop_front();
          }
      }
 
      _GLIBCXX_NODISCARD inline bool
      empty() const
      { return m_bag.empty(); }
      };
 
#ifdef _GLIBCXX_DEBUG
      typedef PB_DS_DEBUG_MAP_BASE_C_DEC        debug_base;
#endif
 
      typedef typename traits_type::null_node_update_pointer null_node_update_pointer;
 
    public:
      typedef pat_trie_tag                      container_category;
      typedef _Alloc                            allocator_type;
      typedef typename _Alloc::size_type        size_type;
      typedef typename _Alloc::difference_type        difference_type;
 
      typedef typename traits_base::key_type          key_type;
      typedef typename traits_base::key_pointer       key_pointer;
      typedef typename traits_base::key_const_pointer       key_const_pointer;
      typedef typename traits_base::key_reference     key_reference;
      typedef typename traits_base::key_const_reference key_const_reference;
      typedef typename traits_base::mapped_type       mapped_type;
      typedef typename traits_base::mapped_pointer    mapped_pointer;
      typedef typename traits_base::mapped_const_pointer mapped_const_pointer;
      typedef typename traits_base::mapped_reference  mapped_reference;
      typedef typename traits_base::mapped_const_reference mapped_const_reference;
      typedef typename traits_base::value_type        value_type;
      typedef typename traits_base::pointer           pointer;
      typedef typename traits_base::const_pointer     const_pointer;
      typedef typename traits_base::reference         reference;
      typedef typename traits_base::const_reference   const_reference;
 
      typedef typename traits_type::access_traits     access_traits;
      typedef typename traits_type::const_iterator    point_const_iterator;
      typedef typename traits_type::iterator          point_iterator;
      typedef point_const_iterator              const_iterator;
      typedef point_iterator                    iterator;
 
      typedef typename traits_type::reverse_iterator  reverse_iterator;
      typedef typename traits_type::const_reverse_iterator const_reverse_iterator;
      typedef typename traits_type::node_const_iterator node_const_iterator;
      typedef typename traits_type::node_iterator     node_iterator;
      typedef typename traits_type::node_update       node_update;
 
      PB_DS_PAT_TRIE_NAME();
 
      PB_DS_PAT_TRIE_NAME(const access_traits&);
 
      PB_DS_PAT_TRIE_NAME(const PB_DS_CLASS_C_DEC&);
 
      void
      swap(PB_DS_CLASS_C_DEC&);
 
      ~PB_DS_PAT_TRIE_NAME();
 
      _GLIBCXX_NODISCARD inline bool
      empty() const;
 
      inline size_type
      size() const;
 
      inline size_type
      max_size() const;
 
      access_traits&
      get_access_traits();
 
      const access_traits&
      get_access_traits() const;
 
      node_update&
      get_node_update();
 
      const node_update&
      get_node_update() const;
 
      inline std::pair<point_iterator, bool>
      insert(const_reference);
 
      inline mapped_reference
      operator[](key_const_reference r_key)
      {
#ifdef PB_DS_DATA_TRUE_INDICATOR
      return insert(std::make_pair(r_key, mapped_type())).first->second;
#else
      insert(r_key);
      return traits_base::s_null_type;
#endif
      }
 
      inline point_iterator
      find(key_const_reference);
 
      inline point_const_iterator
      find(key_const_reference) const;
 
      inline point_iterator
      lower_bound(key_const_reference);
 
      inline point_const_iterator
      lower_bound(key_const_reference) const;
 
      inline point_iterator
      upper_bound(key_const_reference);
 
      inline point_const_iterator
      upper_bound(key_const_reference) const;
 
      void
      clear();
 
      inline bool
      erase(key_const_reference);
 
      inline const_iterator
      erase(const_iterator);
 
#ifdef PB_DS_DATA_TRUE_INDICATOR
      inline iterator
      erase(iterator);
#endif
 
      inline const_reverse_iterator
      erase(const_reverse_iterator);
 
#ifdef PB_DS_DATA_TRUE_INDICATOR
      inline reverse_iterator
      erase(reverse_iterator);
#endif
 
      template<typename Pred>
      inline size_type
      erase_if(Pred);
 
      void
      join(PB_DS_CLASS_C_DEC&);
 
      void
      split(key_const_reference, PB_DS_CLASS_C_DEC&);
 
      inline iterator
      begin();
 
      inline const_iterator
      begin() const;
 
      inline iterator
      end();
 
      inline const_iterator
      end() const;
 
      inline reverse_iterator
      rbegin();
 
      inline const_reverse_iterator
      rbegin() const;
 
      inline reverse_iterator
      rend();
 
      inline const_reverse_iterator
      rend() const;
 
      /// Returns a const node_iterator corresponding to the node at the
      /// root of the tree.
      inline node_const_iterator
      node_begin() const;
 
      /// Returns a node_iterator corresponding to the node at the
      /// root of the tree.
      inline node_iterator
      node_begin();
 
      /// Returns a const node_iterator corresponding to a node just
      /// after a leaf of the tree.
      inline node_const_iterator
      node_end() const;
 
      /// Returns a node_iterator corresponding to a node just
      /// after a leaf of the tree.
      inline node_iterator
      node_end();
 
#ifdef PB_DS_PAT_TRIE_TRACE_
      void
      trace() const;
#endif
 
    protected:
      template<typename It>
      void
      copy_from_range(It, It);
 
      void
      value_swap(PB_DS_CLASS_C_DEC&);
 
      node_pointer
      recursive_copy_node(node_const_pointer);
 
    private:
      void
      initialize();
 
      inline void
      apply_update(node_pointer, null_node_update_pointer);
 
      template<typename Node_Update_>
      inline void
      apply_update(node_pointer, Node_Update_*);
 
      bool
      join_prep(PB_DS_CLASS_C_DEC&, branch_bag&);
 
      void
      rec_join_prep(node_const_pointer, node_const_pointer, branch_bag&);
 
      void
      rec_join_prep(leaf_const_pointer, leaf_const_pointer, branch_bag&);
 
      void
      rec_join_prep(leaf_const_pointer, inode_const_pointer, branch_bag&);
 
      void
      rec_join_prep(inode_const_pointer, leaf_const_pointer, branch_bag&);
 
      void
      rec_join_prep(inode_const_pointer, inode_const_pointer, branch_bag&);
 
      node_pointer
      rec_join(node_pointer, node_pointer, size_type, branch_bag&);
 
      node_pointer
      rec_join(leaf_pointer, leaf_pointer, branch_bag&);
 
      node_pointer
      rec_join(leaf_pointer, inode_pointer, size_type, branch_bag&);
 
      node_pointer
      rec_join(inode_pointer, leaf_pointer, size_type, branch_bag&);
 
      node_pointer
      rec_join(inode_pointer, inode_pointer, branch_bag&);
 
      size_type
      keys_diff_ind(typename access_traits::const_iterator,
                typename access_traits::const_iterator,
                typename access_traits::const_iterator,
                typename access_traits::const_iterator);
 
      inode_pointer
      insert_branch(node_pointer, node_pointer, branch_bag&);
 
      void
      update_min_max_for_inserted_leaf(leaf_pointer);
 
      void
      erase_leaf(leaf_pointer);
 
      inline void
      actual_erase_leaf(leaf_pointer);
 
      void
      clear_imp(node_pointer);
 
      void
      erase_fixup(inode_pointer);
 
      void
      update_min_max_for_erased_leaf(leaf_pointer);
 
      static inline a_const_iterator
      pref_begin(node_const_pointer);
 
      static inline a_const_iterator
      pref_end(node_const_pointer);
 
      inline node_pointer
      find_imp(key_const_reference);
 
      inline node_pointer
      lower_bound_imp(key_const_reference);
 
      inline node_pointer
      upper_bound_imp(key_const_reference);
 
      inline static leaf_const_pointer
      leftmost_descendant(node_const_pointer);
 
      inline static leaf_pointer
      leftmost_descendant(node_pointer);
 
      inline static leaf_const_pointer
      rightmost_descendant(node_const_pointer);
 
      inline static leaf_pointer
      rightmost_descendant(node_pointer);
 
#ifdef _GLIBCXX_DEBUG
      void
      assert_valid(const char*, int) const;
 
      void
      assert_iterators(const char*, int) const;
 
      void
      assert_reverse_iterators(const char*, int) const;
 
      static size_type
      recursive_count_leafs(node_const_pointer, const char*, int);
#endif
 
#ifdef PB_DS_PAT_TRIE_TRACE_
      static void
      trace_node(node_const_pointer, size_type);
 
      template<typename Metadata_>
      static void
      trace_node_metadata(node_const_pointer, type_to_type<Metadata_>);
 
      static void
      trace_node_metadata(node_const_pointer, type_to_type<null_type>);
#endif
 
      leaf_pointer
      split_prep(key_const_reference, PB_DS_CLASS_C_DEC&, branch_bag&);
 
      node_pointer
      rec_split(node_pointer, a_const_iterator, a_const_iterator,
            PB_DS_CLASS_C_DEC&, branch_bag&);
 
      void
      split_insert_branch(size_type, a_const_iterator, inode_iterator,
                    size_type, branch_bag&);
 
      static head_allocator         s_head_allocator;
      static inode_allocator        s_inode_allocator;
      static leaf_allocator         s_leaf_allocator;
 
      head_pointer                  m_p_head;
      size_type               m_size;
    };
 
#define PB_DS_ASSERT_NODE_VALID(X) \
  _GLIBCXX_DEBUG_ONLY(X->assert_valid(this, __FILE__, __LINE__);)
 
#define PB_DS_RECURSIVE_COUNT_LEAFS(X) \
  recursive_count_leafs(X, __FILE__, __LINE__)
 
#include <ext/pb_ds/detail/pat_trie_/constructors_destructor_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/iterators_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/insert_join_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/erase_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/find_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/info_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/policy_access_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/split_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/debug_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/trace_fn_imps.hpp>
#include <ext/pb_ds/detail/pat_trie_/update_fn_imps.hpp>
 
#undef PB_DS_RECURSIVE_COUNT_LEAFS
#undef PB_DS_ASSERT_NODE_VALID
#undef PB_DS_CLASS_C_DEC
#undef PB_DS_CLASS_T_DEC
#undef PB_DS_PAT_TRIE_NAME
#undef PB_DS_PAT_TRIE_TRAITS_BASE
#undef PB_DS_DEBUG_MAP_BASE_C_DEC
  } // namespace detail
} // namespace __gnu_pbds