libstdc++
splay_fn_imps.hpp
Go to the documentation of this file.
1 // -*- C++ -*-
2 
3 // Copyright (C) 2005-2017 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 
41 PB_DS_CLASS_T_DEC
42 void
43 PB_DS_CLASS_C_DEC::
44 splay(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 
91 PB_DS_CLASS_T_DEC
92 inline void
93 PB_DS_CLASS_C_DEC::
94 splay_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 
127 PB_DS_CLASS_T_DEC
128 inline void
129 PB_DS_CLASS_C_DEC::
130 splay_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 
163 PB_DS_CLASS_T_DEC
164 inline void
165 PB_DS_CLASS_C_DEC::
166 splay_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 
199 PB_DS_CLASS_T_DEC
200 inline void
201 PB_DS_CLASS_C_DEC::
202 splay_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 
234 PB_DS_CLASS_T_DEC
235 inline void
236 PB_DS_CLASS_C_DEC::
237 splay_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 
268 PB_DS_CLASS_T_DEC
269 inline void
270 PB_DS_CLASS_C_DEC::
271 splay_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 }