libstdc++: erase_fn_imps.hpp Source File

libstdc++

pairing_heap_/erase_fn_imps.hpp
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1// -*- C++ -*-
2
3// Copyright (C) 2005-2026 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 pairing_heap_/erase_fn_imps.hpp
38 * Contains an implementation class for a pairing heap.
39 */
40
41#ifdef PB_DS_CLASS_C_DEC
42
43PB_DS_CLASS_T_DEC
44void
45PB_DS_CLASS_C_DEC::
46pop()
47{
48 PB_DS_ASSERT_VALID((*this))
49 _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
50
51 node_pointer p_new_root = join_node_children(base_type::m_p_root);
52 PB_DS_ASSERT_NODE_CONSISTENT(p_new_root, false)
53 if (p_new_root != 0)
54 p_new_root->m_p_prev_or_parent = 0;
55
56 base_type::actual_erase_node(base_type::m_p_root);
57 base_type::m_p_root = p_new_root;
58 PB_DS_ASSERT_VALID((*this))
59}
60
61PB_DS_CLASS_T_DEC
62void
63PB_DS_CLASS_C_DEC::
64erase(point_iterator it)
65{
66 PB_DS_ASSERT_VALID((*this))
67 _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
68 remove_node(it.m_p_nd);
69 base_type::actual_erase_node(it.m_p_nd);
70 PB_DS_ASSERT_VALID((*this))
71}
72
73PB_DS_CLASS_T_DEC
74void
75PB_DS_CLASS_C_DEC::
76remove_node(node_pointer p_nd)
77{
78 PB_DS_ASSERT_VALID((*this))
79 _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
80 node_pointer p_new_child = join_node_children(p_nd);
81
82 PB_DS_ASSERT_NODE_CONSISTENT(p_new_child, false)
83
84 if (p_nd == base_type::m_p_root)
85 {
86 if (p_new_child != 0)
87 p_new_child->m_p_prev_or_parent = 0;
88 base_type::m_p_root = p_new_child;
89 PB_DS_ASSERT_NODE_CONSISTENT(base_type::m_p_root, false)
90 return;
91 }
92
93 _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_prev_or_parent != 0);
94 if (p_nd->m_p_prev_or_parent->m_p_l_child == p_nd)
95 {
96 if (p_new_child != 0)
97 {
98 p_new_child->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
99 p_new_child->m_p_next_sibling = p_nd->m_p_next_sibling;
100 if (p_new_child->m_p_next_sibling != 0)
101 p_new_child->m_p_next_sibling->m_p_prev_or_parent = p_new_child;
102 p_nd->m_p_prev_or_parent->m_p_l_child = p_new_child;
103 PB_DS_ASSERT_NODE_CONSISTENT(p_nd->m_p_prev_or_parent, false)
104 return;
105 }
106
107 p_nd->m_p_prev_or_parent->m_p_l_child = p_nd->m_p_next_sibling;
108 if (p_nd->m_p_next_sibling != 0)
109 p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
110 PB_DS_ASSERT_NODE_CONSISTENT(p_nd->m_p_prev_or_parent, false)
111 return;
112 }
113
114 if (p_new_child != 0)
115 {
116 p_new_child->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
117 p_new_child->m_p_next_sibling = p_nd->m_p_next_sibling;
118 if (p_new_child->m_p_next_sibling != 0)
119 p_new_child->m_p_next_sibling->m_p_prev_or_parent = p_new_child;
120 p_new_child->m_p_prev_or_parent->m_p_next_sibling = p_new_child;
121 PB_DS_ASSERT_NODE_CONSISTENT(p_nd->m_p_prev_or_parent, false)
122 return;
123 }
124
125 p_nd->m_p_prev_or_parent->m_p_next_sibling = p_nd->m_p_next_sibling;
126 if (p_nd->m_p_next_sibling != 0)
127 p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
128 PB_DS_ASSERT_NODE_CONSISTENT(p_nd->m_p_prev_or_parent, false)
129}
130
131PB_DS_CLASS_T_DEC
132typename PB_DS_CLASS_C_DEC::node_pointer
133PB_DS_CLASS_C_DEC::
134join_node_children(node_pointer p_nd)
135{
136 _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
137 node_pointer p_ret = p_nd->m_p_l_child;
138 if (p_ret == 0)
139 return 0;
140 while (p_ret->m_p_next_sibling != 0)
141 p_ret = forward_join(p_ret, p_ret->m_p_next_sibling);
142 while (p_ret->m_p_prev_or_parent != p_nd)
143 p_ret = back_join(p_ret->m_p_prev_or_parent, p_ret);
144 PB_DS_ASSERT_NODE_CONSISTENT(p_ret, false)
145 return p_ret;
146}
147
148PB_DS_CLASS_T_DEC
149typename PB_DS_CLASS_C_DEC::node_pointer
150PB_DS_CLASS_C_DEC::
151forward_join(node_pointer p_nd, node_pointer p_next)
152{
153 _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
154 _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_next_sibling == p_next);
155 if (Cmp_Fn::operator()(p_nd->m_value, p_next->m_value))
156 {
157 p_next->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
158 base_type::make_child_of(p_nd, p_next);
159 return p_next->m_p_next_sibling == 0
160 ? p_next : p_next->m_p_next_sibling;
161 }
162
163 if (p_next->m_p_next_sibling != 0)
164 {
165 p_next->m_p_next_sibling->m_p_prev_or_parent = p_nd;
166 p_nd->m_p_next_sibling = p_next->m_p_next_sibling;
167 base_type::make_child_of(p_next, p_nd);
168 return p_nd->m_p_next_sibling;
169 }
170
171 p_nd->m_p_next_sibling = 0;
172 base_type::make_child_of(p_next, p_nd);
173 PB_DS_ASSERT_NODE_CONSISTENT(p_nd, false)
174 return p_nd;
175}
176
177PB_DS_CLASS_T_DEC
178typename PB_DS_CLASS_C_DEC::node_pointer
179PB_DS_CLASS_C_DEC::
180back_join(node_pointer p_nd, node_pointer p_next)
181{
182 _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
183 _GLIBCXX_DEBUG_ASSERT(p_next->m_p_next_sibling == 0);
184
185 if (Cmp_Fn::operator()(p_nd->m_value, p_next->m_value))
186 {
187 p_next->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
188 base_type::make_child_of(p_nd, p_next);
189 PB_DS_ASSERT_NODE_CONSISTENT(p_next, false)
190 return p_next;
191 }
192
193 p_nd->m_p_next_sibling = 0;
194 base_type::make_child_of(p_next, p_nd);
195 PB_DS_ASSERT_NODE_CONSISTENT(p_nd, false)
196 return p_nd;
197}
198
199PB_DS_CLASS_T_DEC
200template<typename Pred>
201typename PB_DS_CLASS_C_DEC::size_type
202PB_DS_CLASS_C_DEC::
203erase_if(Pred pred)
204{
205 PB_DS_ASSERT_VALID((*this))
206 if (base_type::empty())
207 {
208 PB_DS_ASSERT_VALID((*this))
209 return 0;
210 }
211 base_type::to_linked_list();
212 node_pointer p_out = base_type::prune(pred);
213 size_type ersd = 0;
214 while (p_out != 0)
215 {
216 ++ersd;
217 node_pointer p_next = p_out->m_p_next_sibling;
218 base_type::actual_erase_node(p_out);
219 p_out = p_next;
220 }
221
222 node_pointer p_cur = base_type::m_p_root;
223 base_type::m_p_root = 0;
224 while (p_cur != 0)
225 {
226 node_pointer p_next = p_cur->m_p_next_sibling;
227 p_cur->m_p_l_child = p_cur->m_p_next_sibling = p_cur->m_p_prev_or_parent = 0;
228
229 push_imp(p_cur);
230 p_cur = p_next;
231 }
232 PB_DS_ASSERT_VALID((*this))
233 return ersd;
234}
235
236#endif