1 // -*- C++ -*-
2
3 // Copyright (C) 2005, 2006 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 2, 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 // You should have received a copy of the GNU General Public License
17 // along with this library; see the file COPYING. If not, write to
18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
19 // MA 02111-1307, USA.
20
21 // As a special exception, you may use this file as part of a free
22 // software library without restriction. Specifically, if other files
23 // instantiate templates or use macros or inline functions from this
24 // file, or you compile this file and link it with other files to
25 // produce an executable, this file does not by itself cause the
26 // resulting executable to be covered by the GNU General Public
27 // License. This exception does not however invalidate any other
28 // reasons why the executable file might be covered by the GNU General
29 // Public License.
30
31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
32
33 // Permission to use, copy, modify, sell, and distribute this software
34 // is hereby granted without fee, provided that the above copyright
35 // notice appears in all copies, and that both that copyright notice
36 // and this permission notice appear in supporting documentation. None
37 // of the above authors, nor IBM Haifa Research Laboratories, make any
38 // representation about the suitability of this software for any
39 // purpose. It is provided "as is" without express or implied
40 // warranty.
41
42 /**
43 * @file erase_fn_imps.hpp
44 * Contains an implementation class for a pairing heap.
45 */
46
47 PB_DS_CLASS_T_DEC
48 void
49 PB_DS_CLASS_C_DEC::
pop()50 pop()
51 {
52 _GLIBCXX_DEBUG_ONLY(assert_valid();)
53 _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
54
55 node_pointer p_new_root = join_node_children(base_type::m_p_root);
56 _GLIBCXX_DEBUG_ONLY(assert_node_consistent(p_new_root, false);)
57 if (p_new_root != NULL)
58 p_new_root->m_p_prev_or_parent = NULL;
59
60 base_type::actual_erase_node(base_type::m_p_root);
61 base_type::m_p_root = p_new_root;
62 _GLIBCXX_DEBUG_ONLY(assert_valid();)
63 }
64
65 PB_DS_CLASS_T_DEC
66 void
67 PB_DS_CLASS_C_DEC::
erase(point_iterator it)68 erase(point_iterator it)
69 {
70 _GLIBCXX_DEBUG_ONLY(assert_valid();)
71 _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
72 remove_node(it.m_p_nd);
73 base_type::actual_erase_node(it.m_p_nd);
74 _GLIBCXX_DEBUG_ONLY(assert_valid();)
75 }
76
77 PB_DS_CLASS_T_DEC
78 void
79 PB_DS_CLASS_C_DEC::
remove_node(node_pointer p_nd)80 remove_node(node_pointer p_nd)
81 {
82 _GLIBCXX_DEBUG_ONLY(assert_valid();)
83 _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
84 node_pointer p_new_child = join_node_children(p_nd);
85
86 #ifdef _GLIBCXX_DEBUG
87 if (p_new_child != NULL)
88 base_type::assert_node_consistent(p_new_child, false);
89 #endif
90
91 if (p_nd == base_type::m_p_root)
92 {
93 if (p_new_child != NULL)
94 p_new_child->m_p_prev_or_parent = NULL;
95 base_type::m_p_root = p_new_child;
96 _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(base_type::m_p_root, false);)
97 return;
98 }
99
100 _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_prev_or_parent != NULL);
101 if (p_nd->m_p_prev_or_parent->m_p_l_child == p_nd)
102 {
103 if (p_new_child != NULL)
104 {
105 p_new_child->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
106 p_new_child->m_p_next_sibling = p_nd->m_p_next_sibling;
107 if (p_new_child->m_p_next_sibling != NULL)
108 p_new_child->m_p_next_sibling->m_p_prev_or_parent = p_new_child;
109 p_nd->m_p_prev_or_parent->m_p_l_child = p_new_child;
110 _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd->m_p_prev_or_parent, false);)
111 return;
112 }
113
114 p_nd->m_p_prev_or_parent->m_p_l_child = p_nd->m_p_next_sibling;
115 if (p_nd->m_p_next_sibling != NULL)
116 p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
117 _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd->m_p_prev_or_parent, false);)
118 return;
119 }
120
121 if (p_new_child != NULL)
122 {
123 p_new_child->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
124 p_new_child->m_p_next_sibling = p_nd->m_p_next_sibling;
125 if (p_new_child->m_p_next_sibling != NULL)
126 p_new_child->m_p_next_sibling->m_p_prev_or_parent = p_new_child;
127 p_new_child->m_p_prev_or_parent->m_p_next_sibling = p_new_child;
128 _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd->m_p_prev_or_parent, false);)
129 return;
130 }
131
132 p_nd->m_p_prev_or_parent->m_p_next_sibling = p_nd->m_p_next_sibling;
133 if (p_nd->m_p_next_sibling != NULL)
134 p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
135 _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd->m_p_prev_or_parent, false);)
136 }
137
138 PB_DS_CLASS_T_DEC
139 typename PB_DS_CLASS_C_DEC::node_pointer
140 PB_DS_CLASS_C_DEC::
join_node_children(node_pointer p_nd)141 join_node_children(node_pointer p_nd)
142 {
143 _GLIBCXX_DEBUG_ASSERT(p_nd != NULL);
144 node_pointer p_ret = p_nd->m_p_l_child;
145 if (p_ret == NULL)
146 return NULL;
147 while (p_ret->m_p_next_sibling != NULL)
148 p_ret = forward_join(p_ret, p_ret->m_p_next_sibling);
149 while (p_ret->m_p_prev_or_parent != p_nd)
150 p_ret = back_join(p_ret->m_p_prev_or_parent, p_ret);
151 _GLIBCXX_DEBUG_ONLY(assert_node_consistent(p_ret, false);)
152 return p_ret;
153 }
154
155 PB_DS_CLASS_T_DEC
156 typename PB_DS_CLASS_C_DEC::node_pointer
157 PB_DS_CLASS_C_DEC::
forward_join(node_pointer p_nd,node_pointer p_next)158 forward_join(node_pointer p_nd, node_pointer p_next)
159 {
160 _GLIBCXX_DEBUG_ASSERT(p_nd != NULL);
161 _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_next_sibling == p_next);
162 if (Cmp_Fn::operator()(p_nd->m_value, p_next->m_value))
163 {
164 p_next->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
165 base_type::make_child_of(p_nd, p_next);
166 return p_next->m_p_next_sibling == NULL
167 ? p_next : p_next->m_p_next_sibling;
168 }
169
170 if (p_next->m_p_next_sibling != NULL)
171 {
172 p_next->m_p_next_sibling->m_p_prev_or_parent = p_nd;
173 p_nd->m_p_next_sibling = p_next->m_p_next_sibling;
174 base_type::make_child_of(p_next, p_nd);
175 return p_nd->m_p_next_sibling;
176 }
177
178 p_nd->m_p_next_sibling = NULL;
179 base_type::make_child_of(p_next, p_nd);
180 _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd, false));
181 return p_nd;
182 }
183
184 PB_DS_CLASS_T_DEC
185 typename PB_DS_CLASS_C_DEC::node_pointer
186 PB_DS_CLASS_C_DEC::
back_join(node_pointer p_nd,node_pointer p_next)187 back_join(node_pointer p_nd, node_pointer p_next)
188 {
189 _GLIBCXX_DEBUG_ASSERT(p_nd != NULL);
190 _GLIBCXX_DEBUG_ASSERT(p_next->m_p_next_sibling == NULL);
191
192 if (Cmp_Fn::operator()(p_nd->m_value, p_next->m_value))
193 {
194 p_next->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
195 base_type::make_child_of(p_nd, p_next);
196 _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_next, false));
197 return p_next;
198 }
199
200 p_nd->m_p_next_sibling = NULL;
201 base_type::make_child_of(p_next, p_nd);
202 _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd, false));
203 return p_nd;
204 }
205
206 PB_DS_CLASS_T_DEC
207 template<typename Pred>
208 typename PB_DS_CLASS_C_DEC::size_type
209 PB_DS_CLASS_C_DEC::
erase_if(Pred pred)210 erase_if(Pred pred)
211 {
212 _GLIBCXX_DEBUG_ONLY(assert_valid();)
213 if (base_type::empty())
214 {
215 _GLIBCXX_DEBUG_ONLY(assert_valid();)
216 return 0;
217 }
218 base_type::to_linked_list();
219 node_pointer p_out = base_type::prune(pred);
220 size_type ersd = 0;
221 while (p_out != NULL)
222 {
223 ++ersd;
224 node_pointer p_next = p_out->m_p_next_sibling;
225 base_type::actual_erase_node(p_out);
226 p_out = p_next;
227 }
228
229 node_pointer p_cur = base_type::m_p_root;
230 base_type::m_p_root = NULL;
231 while (p_cur != NULL)
232 {
233 node_pointer p_next = p_cur->m_p_next_sibling;
234 p_cur->m_p_l_child = p_cur->m_p_next_sibling = p_cur->m_p_prev_or_parent = NULL;
235
236 push_imp(p_cur);
237 p_cur = p_next;
238 }
239 _GLIBCXX_DEBUG_ONLY(assert_valid();)
240 return ersd;
241 }
242
243