libstdc++-v3/include/ext/pb_ds/detail/rb_tree_map_/erase_fn_imps.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 rb_tree_map_/erase_fn_imps.hpp
  38  * Contains an implementation for rb_tree_.
  39  */
  40
  41 #ifdef PB_DS_CLASS_C_DEC
  42
  43 PB_DS_CLASS_T_DEC
  44 inline bool
  45 PB_DS_CLASS_C_DEC::
  46 erase(key_const_reference r_key)
  47 {
  48   point_iterator it = this->find(r_key);
  49   if (it == base_type::end())
  50     return false;
  51   erase(it);
  52   return true;
  53 }
  54
  55 PB_DS_CLASS_T_DEC
  56 inline typename PB_DS_CLASS_C_DEC::iterator
  57 PB_DS_CLASS_C_DEC::
  58 erase(iterator it)
  59 {
  60   PB_DS_ASSERT_VALID((*this))
  61   if (it == base_type::end())
  62     return it;
  63
  64   iterator ret_it = it;
  65   ++ret_it;
  66   erase_node(it.m_p_nd);
  67   PB_DS_ASSERT_VALID((*this))
  68   return ret_it;
  69 }
  70
  71 PB_DS_CLASS_T_DEC
  72 inline typename PB_DS_CLASS_C_DEC::reverse_iterator
  73 PB_DS_CLASS_C_DEC::
  74 erase(reverse_iterator it)
  75 {
  76   PB_DS_ASSERT_VALID((*this))
  77   if (it.m_p_nd == base_type::m_p_head)
  78     return it;
  79
  80   reverse_iterator ret_it = it;
  81   ++ret_it;
  82   erase_node(it.m_p_nd);
  83   PB_DS_ASSERT_VALID((*this))
  84   return ret_it;
  85 }
  86
  87 PB_DS_CLASS_T_DEC
  88 template<typename Pred>
  89 inline typename PB_DS_CLASS_C_DEC::size_type
  90 PB_DS_CLASS_C_DEC::
  91 erase_if(Pred pred)
  92 {
  93   PB_DS_ASSERT_VALID((*this))
  94   size_type num_ersd = 0;
  95   iterator it = base_type::begin();
  96   while (it != base_type::end())
  97     {
  98       if (pred(*it))
  99         {
 100           ++num_ersd;
 101           it = erase(it);
 102         }
 103       else
 104         ++it;
 105     }
 106
 107   PB_DS_ASSERT_VALID((*this))
 108   return num_ersd;
 109 }
 110
 111 PB_DS_CLASS_T_DEC
 112 void
 113 PB_DS_CLASS_C_DEC::
 114 erase_node(node_pointer p_nd)
 115 {
 116   remove_node(p_nd);
 117   base_type::actual_erase_node(p_nd);
 118   PB_DS_ASSERT_VALID((*this))
 119 }
 120
 121 PB_DS_CLASS_T_DEC
 122 void
 123 PB_DS_CLASS_C_DEC::
 124 remove_node(node_pointer p_z)
 125 {
 126   this->update_min_max_for_erased_node(p_z);
 127   node_pointer p_y = p_z;
 128   node_pointer p_x = 0;
 129   node_pointer p_new_x_parent = 0;
 130
 131   if (p_y->m_p_left == 0)
 132     p_x = p_y->m_p_right;
 133   else if (p_y->m_p_right == 0)
 134     p_x = p_y->m_p_left;
 135   else
 136     {
 137       p_y = p_y->m_p_right;
 138       while (p_y->m_p_left != 0)
 139         p_y = p_y->m_p_left;
 140       p_x = p_y->m_p_right;
 141     }
 142
 143   if (p_y == p_z)
 144     {
 145       p_new_x_parent = p_y->m_p_parent;
 146       if (p_x != 0)
 147         p_x->m_p_parent = p_y->m_p_parent;
 148
 149       if (base_type::m_p_head->m_p_parent == p_z)
 150         base_type::m_p_head->m_p_parent = p_x;
 151       else if (p_z->m_p_parent->m_p_left == p_z)
 152         {
 153           p_y->m_p_left = p_z->m_p_parent;
 154           p_z->m_p_parent->m_p_left = p_x;
 155         }
 156       else
 157         {
 158           p_y->m_p_left = 0;
 159           p_z->m_p_parent->m_p_right = p_x;
 160         }
 161     }
 162   else
 163     {
 164       p_z->m_p_left->m_p_parent = p_y;
 165       p_y->m_p_left = p_z->m_p_left;
 166       if (p_y != p_z->m_p_right)
 167         {
 168           p_new_x_parent = p_y->m_p_parent;
 169           if (p_x != 0)
 170             p_x->m_p_parent = p_y->m_p_parent;
 171           p_y->m_p_parent->m_p_left = p_x;
 172           p_y->m_p_right = p_z->m_p_right;
 173           p_z->m_p_right->m_p_parent = p_y;
 174         }
 175       else
 176         p_new_x_parent = p_y;
 177
 178       if (base_type::m_p_head->m_p_parent == p_z)
 179         base_type::m_p_head->m_p_parent = p_y;
 180       else if (p_z->m_p_parent->m_p_left == p_z)
 181         p_z->m_p_parent->m_p_left = p_y;
 182       else
 183         p_z->m_p_parent->m_p_right = p_y;
 184
 185       p_y->m_p_parent = p_z->m_p_parent;
 186       std::swap(p_y->m_red, p_z->m_red);
 187       p_y = p_z;
 188     }
 189
 190   this->update_to_top(p_new_x_parent, (node_update* )this);
 191
 192   if (p_y->m_red)
 193     return;
 194
 195   remove_fixup(p_x, p_new_x_parent);
 196 }
 197
 198 PB_DS_CLASS_T_DEC
 199 void
 200 PB_DS_CLASS_C_DEC::
 201 remove_fixup(node_pointer p_x, node_pointer p_new_x_parent)
 202 {
 203   _GLIBCXX_DEBUG_ASSERT(p_x == 0 || p_x->m_p_parent == p_new_x_parent);
 204
 205   while (p_x != base_type::m_p_head->m_p_parent && is_effectively_black(p_x))
 206     if (p_x == p_new_x_parent->m_p_left)
 207       {
 208         node_pointer p_w = p_new_x_parent->m_p_right;
 209         if (p_w->m_red)
 210           {
 211             p_w->m_red = false;
 212             p_new_x_parent->m_red = true;
 213             base_type::rotate_left(p_new_x_parent);
 214             p_w = p_new_x_parent->m_p_right;
 215           }
 216
 217         if (is_effectively_black(p_w->m_p_left)
 218             && is_effectively_black(p_w->m_p_right))
 219           {
 220             p_w->m_red = true;
 221             p_x = p_new_x_parent;
 222             p_new_x_parent = p_new_x_parent->m_p_parent;
 223           }
 224         else
 225           {
 226             if (is_effectively_black(p_w->m_p_right))
 227               {
 228                 if (p_w->m_p_left != 0)
 229                   p_w->m_p_left->m_red = false;
 230
 231                 p_w->m_red = true;
 232                 base_type::rotate_right(p_w);
 233                 p_w = p_new_x_parent->m_p_right;
 234               }
 235
 236             p_w->m_red = p_new_x_parent->m_red;
 237             p_new_x_parent->m_red = false;
 238
 239             if (p_w->m_p_right != 0)
 240               p_w->m_p_right->m_red = false;
 241
 242             base_type::rotate_left(p_new_x_parent);
 243             this->update_to_top(p_new_x_parent, (node_update* )this);
 244             break;
 245           }
 246       }
 247     else
 248       {
 249         node_pointer p_w = p_new_x_parent->m_p_left;
 250         if (p_w->m_red == true)
 251           {
 252             p_w->m_red = false;
 253             p_new_x_parent->m_red = true;
 254             base_type::rotate_right(p_new_x_parent);
 255             p_w = p_new_x_parent->m_p_left;
 256           }
 257
 258         if (is_effectively_black(p_w->m_p_right)
 259             && is_effectively_black(p_w->m_p_left))
 260           {
 261             p_w->m_red = true;
 262             p_x = p_new_x_parent;
 263             p_new_x_parent = p_new_x_parent->m_p_parent;
 264           }
 265         else
 266           {
 267             if (is_effectively_black(p_w->m_p_left))
 268               {
 269                 if (p_w->m_p_right != 0)
 270                   p_w->m_p_right->m_red = false;
 271
 272                 p_w->m_red = true;
 273                 base_type::rotate_left(p_w);
 274                 p_w = p_new_x_parent->m_p_left;
 275               }
 276
 277             p_w->m_red = p_new_x_parent->m_red;
 278             p_new_x_parent->m_red = false;
 279
 280             if (p_w->m_p_left != 0)
 281               p_w->m_p_left->m_red = false;
 282
 283             base_type::rotate_right(p_new_x_parent);
 284             this->update_to_top(p_new_x_parent, (node_update* )this);
 285             break;
 286           }
 287       }
 288
 289   if (p_x != 0)
 290     p_x->m_red = false;
 291 }
 292 #endif