libstdc++
splay_fn_imps.hpp
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1// -*- C++ -*-
2
3// Copyright (C) 2005-2019 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 splay_tree_/splay_fn_imps.hpp
38 * Contains an implementation class for splay_tree_.
39 */
40
41PB_DS_CLASS_T_DEC
42void
43PB_DS_CLASS_C_DEC::
44splay(node_pointer p_nd)
45{
46 while (p_nd->m_p_parent != base_type::m_p_head)
47 {
48#ifdef _GLIBCXX_DEBUG
49 {
50 node_pointer p_head = base_type::m_p_head;
51 assert_special_imp(p_head, __FILE__, __LINE__);
52 }
53#endif
54
55 PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
56
57 if (p_nd->m_p_parent->m_p_parent == base_type::m_p_head)
58 {
59 base_type::rotate_parent(p_nd);
60 _GLIBCXX_DEBUG_ASSERT(p_nd == this->m_p_head->m_p_parent);
61 }
62 else
63 {
64 const node_pointer p_parent = p_nd->m_p_parent;
65 const node_pointer p_grandparent = p_parent->m_p_parent;
66
67#ifdef _GLIBCXX_DEBUG
68 const size_type total =
69 base_type::recursive_count(p_grandparent);
70 _GLIBCXX_DEBUG_ASSERT(total >= 3);
71#endif
72
73 if (p_parent->m_p_left == p_nd &&
74 p_grandparent->m_p_right == p_parent)
75 splay_zig_zag_left(p_nd, p_parent, p_grandparent);
76 else if (p_parent->m_p_right == p_nd &&
77 p_grandparent->m_p_left == p_parent)
78 splay_zig_zag_right(p_nd, p_parent, p_grandparent);
79 else if (p_parent->m_p_left == p_nd &&
80 p_grandparent->m_p_left == p_parent)
81 splay_zig_zig_left(p_nd, p_parent, p_grandparent);
82 else
83 splay_zig_zig_right(p_nd, p_parent, p_grandparent);
84 _GLIBCXX_DEBUG_ASSERT(total ==this->recursive_count(p_nd));
85 }
86
87 PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
88 }
89}
90
91PB_DS_CLASS_T_DEC
92inline void
93PB_DS_CLASS_C_DEC::
94splay_zig_zag_left(node_pointer p_nd, node_pointer p_parent,
95 node_pointer p_grandparent)
96{
97 _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
98 _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
99
100 PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
101
102 _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_left == p_nd &&
103 p_grandparent->m_p_right == p_parent);
104
105 splay_zz_start(p_nd, p_parent, p_grandparent);
106
107 node_pointer p_b = p_nd->m_p_right;
108 node_pointer p_c = p_nd->m_p_left;
109
110 p_nd->m_p_right = p_parent;
111 p_parent->m_p_parent = p_nd;
112
113 p_nd->m_p_left = p_grandparent;
114 p_grandparent->m_p_parent = p_nd;
115
116 p_parent->m_p_left = p_b;
117 if (p_b != 0)
118 p_b->m_p_parent = p_parent;
119
120 p_grandparent->m_p_right = p_c;
121 if (p_c != 0)
122 p_c->m_p_parent = p_grandparent;
123
124 splay_zz_end(p_nd, p_parent, p_grandparent);
125}
126
127PB_DS_CLASS_T_DEC
128inline void
129PB_DS_CLASS_C_DEC::
130splay_zig_zag_right(node_pointer p_nd, node_pointer p_parent,
131 node_pointer p_grandparent)
132{
133 _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
134 _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
135
136 PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
137
138 _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_right == p_nd &&
139 p_grandparent->m_p_left == p_parent);
140
141 splay_zz_start(p_nd, p_parent, p_grandparent);
142
143 node_pointer p_b = p_nd->m_p_left;
144 node_pointer p_c = p_nd->m_p_right;
145
146 p_nd->m_p_left = p_parent;
147 p_parent->m_p_parent = p_nd;
148
149 p_nd->m_p_right = p_grandparent;
150 p_grandparent->m_p_parent = p_nd;
151
152 p_parent->m_p_right = p_b;
153 if (p_b != 0)
154 p_b->m_p_parent = p_parent;
155
156 p_grandparent->m_p_left = p_c;
157 if (p_c != 0)
158 p_c->m_p_parent = p_grandparent;
159
160 splay_zz_end(p_nd, p_parent, p_grandparent);
161}
162
163PB_DS_CLASS_T_DEC
164inline void
165PB_DS_CLASS_C_DEC::
166splay_zig_zig_left(node_pointer p_nd, node_pointer p_parent,
167 node_pointer p_grandparent)
168{
169 _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
170 _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
171
172 PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
173
174 _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_left == p_nd &&
175 p_nd->m_p_parent->m_p_parent->m_p_left == p_nd->m_p_parent);
176
177 splay_zz_start(p_nd, p_parent, p_grandparent);
178
179 node_pointer p_b = p_nd->m_p_right;
180 node_pointer p_c = p_parent->m_p_right;
181
182 p_nd->m_p_right = p_parent;
183 p_parent->m_p_parent = p_nd;
184
185 p_parent->m_p_right = p_grandparent;
186 p_grandparent->m_p_parent = p_parent;
187
188 p_parent->m_p_left = p_b;
189 if (p_b != 0)
190 p_b->m_p_parent = p_parent;
191
192 p_grandparent->m_p_left = p_c;
193 if (p_c != 0)
194 p_c->m_p_parent = p_grandparent;
195
196 splay_zz_end(p_nd, p_parent, p_grandparent);
197}
198
199PB_DS_CLASS_T_DEC
200inline void
201PB_DS_CLASS_C_DEC::
202splay_zig_zig_right(node_pointer p_nd, node_pointer p_parent,
203 node_pointer p_grandparent)
204{
205 _GLIBCXX_DEBUG_ASSERT(p_parent == p_nd->m_p_parent);
206 _GLIBCXX_DEBUG_ASSERT(p_grandparent == p_parent->m_p_parent);
207 PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_grandparent)
208 _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_right == p_nd &&
209 p_nd->m_p_parent->m_p_parent->m_p_right == p_nd->m_p_parent);
210
211 splay_zz_start(p_nd, p_parent, p_grandparent);
212
213 node_pointer p_b = p_nd->m_p_left;
214 node_pointer p_c = p_parent->m_p_left;
215
216 p_nd->m_p_left = p_parent;
217 p_parent->m_p_parent = p_nd;
218
219 p_parent->m_p_left = p_grandparent;
220 p_grandparent->m_p_parent = p_parent;
221
222 p_parent->m_p_right = p_b;
223 if (p_b != 0)
224 p_b->m_p_parent = p_parent;
225
226 p_grandparent->m_p_right = p_c;
227 if (p_c != 0)
228 p_c->m_p_parent = p_grandparent;
229
230 base_type::update_to_top(p_grandparent, (node_update*)this);
231 splay_zz_end(p_nd, p_parent, p_grandparent);
232}
233
234PB_DS_CLASS_T_DEC
235inline void
236PB_DS_CLASS_C_DEC::
237splay_zz_start(node_pointer p_nd,
238#ifdef _GLIBCXX_DEBUG
239 node_pointer p_parent,
240#else
241 node_pointer /*p_parent*/,
242#endif
243 node_pointer p_grandparent)
244{
245 _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
246 _GLIBCXX_DEBUG_ASSERT(p_parent != 0);
247 _GLIBCXX_DEBUG_ASSERT(p_grandparent != 0);
248
249 const bool grandparent_head = p_grandparent->m_p_parent == base_type::m_p_head;
250
251 if (grandparent_head)
252 {
253 base_type::m_p_head->m_p_parent = base_type::m_p_head->m_p_parent;
254 p_nd->m_p_parent = base_type::m_p_head;
255 return;
256 }
257
258 node_pointer p_greatgrandparent = p_grandparent->m_p_parent;
259
260 p_nd->m_p_parent = p_greatgrandparent;
261
262 if (p_grandparent == p_greatgrandparent->m_p_left)
263 p_greatgrandparent->m_p_left = p_nd;
264 else
265 p_greatgrandparent->m_p_right = p_nd;
266}
267
268PB_DS_CLASS_T_DEC
269inline void
270PB_DS_CLASS_C_DEC::
271splay_zz_end(node_pointer p_nd, node_pointer p_parent,
272 node_pointer p_grandparent)
273{
274 if (p_nd->m_p_parent == base_type::m_p_head)
275 base_type::m_p_head->m_p_parent = p_nd;
276
277 this->apply_update(p_grandparent, (node_update*)this);
278 this->apply_update(p_parent, (node_update*)this);
279 this->apply_update(p_nd, (node_update*)this);
280 PB_DS_ASSERT_BASE_NODE_CONSISTENT(p_nd)
281}