1 // -*- C++ -*- 2 3 // Copyright (C) 2005-2018 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 PB_DS_CLASS_T_DEC 42 inline bool 43 PB_DS_CLASS_C_DEC:: 44 erase(key_const_reference r_key) 45 { 46 point_iterator it = this->find(r_key); 47 if (it == base_type::end()) 48 return false; 49 erase(it); 50 return true; 51 } 52 53 PB_DS_CLASS_T_DEC 54 inline typename PB_DS_CLASS_C_DEC::iterator 55 PB_DS_CLASS_C_DEC:: 56 erase(iterator it) 57 { 58 PB_DS_ASSERT_VALID((*this)) 59 if (it == base_type::end()) 60 return it; 61 62 iterator ret_it = it; 63 ++ret_it; 64 erase_node(it.m_p_nd); 65 PB_DS_ASSERT_VALID((*this)) 66 return ret_it; 67 } 68 69 PB_DS_CLASS_T_DEC 70 inline typename PB_DS_CLASS_C_DEC::reverse_iterator 71 PB_DS_CLASS_C_DEC:: 72 erase(reverse_iterator it) 73 { 74 PB_DS_ASSERT_VALID((*this)) 75 if (it.m_p_nd == base_type::m_p_head) 76 return it; 77 78 reverse_iterator ret_it = it; 79 ++ret_it; 80 erase_node(it.m_p_nd); 81 PB_DS_ASSERT_VALID((*this)) 82 return ret_it; 83 } 84 85 PB_DS_CLASS_T_DEC 86 template<typename Pred> 87 inline typename PB_DS_CLASS_C_DEC::size_type 88 PB_DS_CLASS_C_DEC:: 89 erase_if(Pred pred) 90 { 91 PB_DS_ASSERT_VALID((*this)) 92 size_type num_ersd = 0; 93 iterator it = base_type::begin(); 94 while (it != base_type::end()) 95 { 96 if (pred(*it)) 97 { 98 ++num_ersd; 99 it = erase(it); 100 } 101 else 102 ++it; 103 } 104 105 PB_DS_ASSERT_VALID((*this)) 106 return num_ersd; 107 } 108 109 PB_DS_CLASS_T_DEC 110 void 111 PB_DS_CLASS_C_DEC:: 112 erase_node(node_pointer p_nd) 113 { 114 remove_node(p_nd); 115 base_type::actual_erase_node(p_nd); 116 PB_DS_ASSERT_VALID((*this)) 117 } 118 119 PB_DS_CLASS_T_DEC 120 void 121 PB_DS_CLASS_C_DEC:: 122 remove_node(node_pointer p_z) 123 { 124 this->update_min_max_for_erased_node(p_z); 125 node_pointer p_y = p_z; 126 node_pointer p_x = 0; 127 node_pointer p_new_x_parent = 0; 128 129 if (p_y->m_p_left == 0) 130 p_x = p_y->m_p_right; 131 else if (p_y->m_p_right == 0) 132 p_x = p_y->m_p_left; 133 else 134 { 135 p_y = p_y->m_p_right; 136 while (p_y->m_p_left != 0) 137 p_y = p_y->m_p_left; 138 p_x = p_y->m_p_right; 139 } 140 141 if (p_y == p_z) 142 { 143 p_new_x_parent = p_y->m_p_parent; 144 if (p_x != 0) 145 p_x->m_p_parent = p_y->m_p_parent; 146 147 if (base_type::m_p_head->m_p_parent == p_z) 148 base_type::m_p_head->m_p_parent = p_x; 149 else if (p_z->m_p_parent->m_p_left == p_z) 150 { 151 p_y->m_p_left = p_z->m_p_parent; 152 p_z->m_p_parent->m_p_left = p_x; 153 } 154 else 155 { 156 p_y->m_p_left = 0; 157 p_z->m_p_parent->m_p_right = p_x; 158 } 159 } 160 else 161 { 162 p_z->m_p_left->m_p_parent = p_y; 163 p_y->m_p_left = p_z->m_p_left; 164 if (p_y != p_z->m_p_right) 165 { 166 p_new_x_parent = p_y->m_p_parent; 167 if (p_x != 0) 168 p_x->m_p_parent = p_y->m_p_parent; 169 p_y->m_p_parent->m_p_left = p_x; 170 p_y->m_p_right = p_z->m_p_right; 171 p_z->m_p_right->m_p_parent = p_y; 172 } 173 else 174 p_new_x_parent = p_y; 175 176 if (base_type::m_p_head->m_p_parent == p_z) 177 base_type::m_p_head->m_p_parent = p_y; 178 else if (p_z->m_p_parent->m_p_left == p_z) 179 p_z->m_p_parent->m_p_left = p_y; 180 else 181 p_z->m_p_parent->m_p_right = p_y; 182 183 p_y->m_p_parent = p_z->m_p_parent; 184 std::swap(p_y->m_red, p_z->m_red); 185 p_y = p_z; 186 } 187 188 this->update_to_top(p_new_x_parent, (node_update* )this); 189 190 if (p_y->m_red) 191 return; 192 193 remove_fixup(p_x, p_new_x_parent); 194 } 195 196 PB_DS_CLASS_T_DEC 197 void 198 PB_DS_CLASS_C_DEC:: 199 remove_fixup(node_pointer p_x, node_pointer p_new_x_parent) 200 { 201 _GLIBCXX_DEBUG_ASSERT(p_x == 0 || p_x->m_p_parent == p_new_x_parent); 202 203 while (p_x != base_type::m_p_head->m_p_parent && is_effectively_black(p_x)) 204 if (p_x == p_new_x_parent->m_p_left) 205 { 206 node_pointer p_w = p_new_x_parent->m_p_right; 207 if (p_w->m_red) 208 { 209 p_w->m_red = false; 210 p_new_x_parent->m_red = true; 211 base_type::rotate_left(p_new_x_parent); 212 p_w = p_new_x_parent->m_p_right; 213 } 214 215 if (is_effectively_black(p_w->m_p_left) 216 && is_effectively_black(p_w->m_p_right)) 217 { 218 p_w->m_red = true; 219 p_x = p_new_x_parent; 220 p_new_x_parent = p_new_x_parent->m_p_parent; 221 } 222 else 223 { 224 if (is_effectively_black(p_w->m_p_right)) 225 { 226 if (p_w->m_p_left != 0) 227 p_w->m_p_left->m_red = false; 228 229 p_w->m_red = true; 230 base_type::rotate_right(p_w); 231 p_w = p_new_x_parent->m_p_right; 232 } 233 234 p_w->m_red = p_new_x_parent->m_red; 235 p_new_x_parent->m_red = false; 236 237 if (p_w->m_p_right != 0) 238 p_w->m_p_right->m_red = false; 239 240 base_type::rotate_left(p_new_x_parent); 241 this->update_to_top(p_new_x_parent, (node_update* )this); 242 break; 243 } 244 } 245 else 246 { 247 node_pointer p_w = p_new_x_parent->m_p_left; 248 if (p_w->m_red == true) 249 { 250 p_w->m_red = false; 251 p_new_x_parent->m_red = true; 252 base_type::rotate_right(p_new_x_parent); 253 p_w = p_new_x_parent->m_p_left; 254 } 255 256 if (is_effectively_black(p_w->m_p_right) 257 && is_effectively_black(p_w->m_p_left)) 258 { 259 p_w->m_red = true; 260 p_x = p_new_x_parent; 261 p_new_x_parent = p_new_x_parent->m_p_parent; 262 } 263 else 264 { 265 if (is_effectively_black(p_w->m_p_left)) 266 { 267 if (p_w->m_p_right != 0) 268 p_w->m_p_right->m_red = false; 269 270 p_w->m_red = true; 271 base_type::rotate_left(p_w); 272 p_w = p_new_x_parent->m_p_left; 273 } 274 275 p_w->m_red = p_new_x_parent->m_red; 276 p_new_x_parent->m_red = false; 277 278 if (p_w->m_p_left != 0) 279 p_w->m_p_left->m_red = false; 280 281 base_type::rotate_right(p_new_x_parent); 282 this->update_to_top(p_new_x_parent, (node_update* )this); 283 break; 284 } 285 } 286 287 if (p_x != 0) 288 p_x->m_red = false; 289 } 290