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

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2023 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/order_statistics_imp.hpp
  38  * Contains forward declarations for order_statistics_key
  39  */
  40
  41 #ifdef PB_DS_CLASS_C_DEC
  42
  43 PB_DS_CLASS_T_DEC
  44 inline typename PB_DS_CLASS_C_DEC::iterator
  45 PB_DS_CLASS_C_DEC::
  46 find_by_order(size_type order)
  47 {
  48   if (empty())
  49     return end();
  50
  51   ++order;
  52   node_iterator nd_it = node_begin();
  53
  54   while (true)
  55     {
  56       if (order > nd_it.get_metadata())
  57         return ++base_type::rightmost_it(nd_it);
  58
  59       const size_type num_children = nd_it.num_children();
  60       if (num_children == 0)
  61         return *nd_it;
  62
  63       for (size_type i = 0; i < num_children; ++i)
  64         {
  65           node_iterator child_nd_it = nd_it.get_child(i);
  66           if (order <= child_nd_it.get_metadata())
  67             {
  68               i = num_children;
  69               nd_it = child_nd_it;
  70             }
  71           else
  72             order -= child_nd_it.get_metadata();
  73         }
  74     }
  75 }
  76
  77 PB_DS_CLASS_T_DEC
  78 inline typename PB_DS_CLASS_C_DEC::const_iterator
  79 PB_DS_CLASS_C_DEC::
  80 find_by_order(size_type order) const
  81 { return const_cast<PB_DS_CLASS_C_DEC*>(this)->find_by_order(order); }
  82
  83 PB_DS_CLASS_T_DEC
  84 inline typename PB_DS_CLASS_C_DEC::size_type
  85 PB_DS_CLASS_C_DEC::
  86 order_of_key(key_const_reference r_key) const
  87 {
  88   const _ATraits& r_traits =
  89     const_cast<PB_DS_CLASS_C_DEC* >(this)->get_access_traits();
  90
  91   return order_of_prefix(r_traits.begin(r_key), r_traits.end(r_key));
  92 }
  93
  94 PB_DS_CLASS_T_DEC
  95 inline typename PB_DS_CLASS_C_DEC::size_type
  96 PB_DS_CLASS_C_DEC::
  97 order_of_prefix(typename access_traits::const_iterator b,
  98                 typename access_traits::const_iterator e) const
  99 {
 100   if (empty())
 101     return 0;
 102
 103   const _ATraits& r_traits =
 104     const_cast<PB_DS_CLASS_C_DEC*>(this)->get_access_traits();
 105
 106   node_const_iterator nd_it = node_begin();
 107   node_const_iterator end_nd_it = node_end();
 108   size_type ord = 0;
 109
 110   while (true)
 111     {
 112       const size_type num_children = nd_it.num_children();
 113       if (num_children == 0)
 114         {
 115           key_const_reference r_key = base_type::extract_key(*(*nd_it));
 116           typename access_traits::const_iterator key_b =
 117             r_traits.begin(r_key);
 118
 119           typename access_traits::const_iterator key_e =
 120             r_traits.end(r_key);
 121
 122           return (base_type::less(key_b, key_e,  b, e,  r_traits)) ?
 123                   ord + 1 : ord;
 124         }
 125
 126       node_const_iterator next_nd_it = end_nd_it;
 127       size_type i = num_children - 1;
 128
 129       do
 130         {
 131           node_const_iterator child_nd_it = nd_it.get_child(i);
 132
 133           if (next_nd_it != end_nd_it)
 134             ord += child_nd_it.get_metadata();
 135           else if (!base_type::less(b, e,
 136                                     child_nd_it.valid_prefix().first,
 137                                     child_nd_it.valid_prefix().second,
 138                                     r_traits))
 139             next_nd_it = child_nd_it;
 140         }
 141       while (i-- > 0);
 142
 143       if (next_nd_it == end_nd_it)
 144         return ord;
 145
 146       nd_it = next_nd_it;
 147     }
 148 }
 149
 150 PB_DS_CLASS_T_DEC
 151 inline void
 152 PB_DS_CLASS_C_DEC::
 153 operator()(node_iterator nd_it, node_const_iterator /*end_nd_it*/) const
 154 {
 155   const size_type num_children = nd_it.num_children();
 156   size_type children_rank = 0;
 157   for (size_type i = 0; i < num_children; ++i)
 158     children_rank += nd_it.get_child(i).get_metadata();
 159
 160   const size_type res = (num_children == 0) ? 1 : children_rank;
 161   const_cast<size_type&>(nd_it.get_metadata()) = res;
 162 }
 163 #endif