libstdc++

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