erase_fn_imps.hpp revision 1.8 
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 pairing_heap_/erase_fn_imps.hpp
38 * Contains an implementation class for a pairing heap.
39 */
40
41PB_DS_CLASS_T_DEC
42void
43PB_DS_CLASS_C_DEC::
44pop()
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
59PB_DS_CLASS_T_DEC
60void
61PB_DS_CLASS_C_DEC::
62erase(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
71PB_DS_CLASS_T_DEC
72void
73PB_DS_CLASS_C_DEC::
74remove_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
129PB_DS_CLASS_T_DEC
130typename PB_DS_CLASS_C_DEC::node_pointer
131PB_DS_CLASS_C_DEC::
132join_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
146PB_DS_CLASS_T_DEC
147typename PB_DS_CLASS_C_DEC::node_pointer
148PB_DS_CLASS_C_DEC::
149forward_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
175PB_DS_CLASS_T_DEC
176typename PB_DS_CLASS_C_DEC::node_pointer
177PB_DS_CLASS_C_DEC::
178back_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
197PB_DS_CLASS_T_DEC
198template<typename Pred>
199typename PB_DS_CLASS_C_DEC::size_type
200PB_DS_CLASS_C_DEC::
201erase_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
234