1 // -*- C++ -*-
2
3 // Copyright (C) 2005-2022 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::
erase(key_const_reference r_key)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::
erase(iterator it)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::
erase(reverse_iterator it)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::
erase_if(Pred pred)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::
erase_node(node_pointer p_nd)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::
remove_node(node_pointer p_z)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::
remove_fixup(node_pointer p_x,node_pointer p_new_x_parent)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
293