libstdc++

rb_tree_map_/erase_fn_imps.hpp
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1 // -*- C++ -*-
2
3 // Copyright (C) 2005-2013 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 }