libstdc++
bin_search_tree_/rotate_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 bin_search_tree_/rotate_fn_imps.hpp
38  * Contains imps for rotating nodes.
39  */
40 
41 PB_DS_CLASS_T_DEC
42 inline void
43 PB_DS_CLASS_C_DEC::
44 rotate_left(node_pointer p_x)
45 {
46  node_pointer p_y = p_x->m_p_right;
47 
48  p_x->m_p_right = p_y->m_p_left;
49 
50  if (p_y->m_p_left != 0)
51  p_y->m_p_left->m_p_parent = p_x;
52 
53  p_y->m_p_parent = p_x->m_p_parent;
54 
55  if (p_x == m_p_head->m_p_parent)
56  m_p_head->m_p_parent = p_y;
57  else if (p_x == p_x->m_p_parent->m_p_left)
58  p_x->m_p_parent->m_p_left = p_y;
59  else
60  p_x->m_p_parent->m_p_right = p_y;
61 
62  p_y->m_p_left = p_x;
63  p_x->m_p_parent = p_y;
64 
65  PB_DS_ASSERT_NODE_CONSISTENT(p_x)
66  PB_DS_ASSERT_NODE_CONSISTENT(p_y)
67 
68  apply_update(p_x, (node_update* )this);
69  apply_update(p_x->m_p_parent, (node_update* )this);
70 }
71 
72 PB_DS_CLASS_T_DEC
73 inline void
74 PB_DS_CLASS_C_DEC::
75 rotate_right(node_pointer p_x)
76 {
77  node_pointer p_y = p_x->m_p_left;
78 
79  p_x->m_p_left = p_y->m_p_right;
80 
81  if (p_y->m_p_right != 0)
82  p_y->m_p_right->m_p_parent = p_x;
83 
84  p_y->m_p_parent = p_x->m_p_parent;
85 
86  if (p_x == m_p_head->m_p_parent)
87  m_p_head->m_p_parent = p_y;
88  else if (p_x == p_x->m_p_parent->m_p_right)
89  p_x->m_p_parent->m_p_right = p_y;
90  else
91  p_x->m_p_parent->m_p_left = p_y;
92 
93  p_y->m_p_right = p_x;
94  p_x->m_p_parent = p_y;
95 
96  PB_DS_ASSERT_NODE_CONSISTENT(p_x)
97  PB_DS_ASSERT_NODE_CONSISTENT(p_y)
98 
99  apply_update(p_x, (node_update* )this);
100  apply_update(p_x->m_p_parent, (node_update* )this);
101 }
102 
103 PB_DS_CLASS_T_DEC
104 inline void
105 PB_DS_CLASS_C_DEC::
106 rotate_parent(node_pointer p_nd)
107 {
108  node_pointer p_parent = p_nd->m_p_parent;
109 
110  if (p_nd == p_parent->m_p_left)
111  rotate_right(p_parent);
112  else
113  rotate_left(p_parent);
114 
115  _GLIBCXX_DEBUG_ASSERT(p_parent->m_p_parent = p_nd);
116  _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_left == p_parent ||
117  p_nd->m_p_right == p_parent);
118 }
119 
120 PB_DS_CLASS_T_DEC
121 inline void
122 PB_DS_CLASS_C_DEC::
123 apply_update(node_pointer /*p_nd*/, null_node_update_pointer /*p_update*/)
124 { }
125 
126 PB_DS_CLASS_T_DEC
127 template<typename Node_Update_>
128 inline void
129 PB_DS_CLASS_C_DEC::
130 apply_update(node_pointer p_nd, Node_Update_* /*p_update*/)
131 {
132  node_update::operator()(node_iterator(p_nd),
133  node_const_iterator(static_cast<node_pointer>(0)));
134 }
135 
136 PB_DS_CLASS_T_DEC
137 template<typename Node_Update_>
138 inline void
139 PB_DS_CLASS_C_DEC::
140 update_to_top(node_pointer p_nd, Node_Update_* p_update)
141 {
142  while (p_nd != m_p_head)
143  {
144  apply_update(p_nd, p_update);
145 
146  p_nd = p_nd->m_p_parent;
147  }
148 }
149 
150 PB_DS_CLASS_T_DEC
151 inline void
152 PB_DS_CLASS_C_DEC::
153 update_to_top(node_pointer /*p_nd*/, null_node_update_pointer /*p_update*/)
154 { }
155