libstdc++
binomial_heap_base_/erase_fn_imps.hpp
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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
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9 // version.
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16 // Under Section 7 of GPL version 3, you are granted additional
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18 // 3.1, as published by the Free Software Foundation.
19 
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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
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35 
36 /**
37  * @file binomial_heap_base_/erase_fn_imps.hpp
38  * Contains an implementation class for a base of binomial heaps.
39  */
40 
41 PB_DS_CLASS_T_DEC
42 void
43 PB_DS_CLASS_C_DEC::
44 pop()
45 {
46  PB_DS_ASSERT_VALID_COND((*this),true)
47  _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
48 
49  if (m_p_max == 0)
50  find_max();
51 
52  _GLIBCXX_DEBUG_ASSERT(m_p_max != 0);
53  node_pointer p_nd = m_p_max;
54  remove_parentless_node(m_p_max);
55  base_type::actual_erase_node(p_nd);
56  m_p_max = 0;
57  PB_DS_ASSERT_VALID_COND((*this),true)
58 }
59 
60 PB_DS_CLASS_T_DEC
61 void
62 PB_DS_CLASS_C_DEC::
63 remove_parentless_node(node_pointer p_nd)
64 {
65  _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
66  _GLIBCXX_DEBUG_ASSERT(base_type::parent(p_nd) == 0);
67 
68  node_pointer p_cur_root = p_nd == base_type::m_p_root?
69  p_nd->m_p_next_sibling : base_type::m_p_root;
70 
71  if (p_cur_root != 0)
72  p_cur_root->m_p_prev_or_parent = 0;
73 
74  if (p_nd->m_p_prev_or_parent != 0)
75  p_nd->m_p_prev_or_parent->m_p_next_sibling = p_nd->m_p_next_sibling;
76 
77  if (p_nd->m_p_next_sibling != 0)
78  p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
79 
80  node_pointer p_child = p_nd->m_p_l_child;
81  if (p_child != 0)
82  {
83  p_child->m_p_prev_or_parent = 0;
84  while (p_child->m_p_next_sibling != 0)
85  p_child = p_child->m_p_next_sibling;
86  }
87 
88  m_p_max = 0;
89  base_type::m_p_root = join(p_cur_root, p_child);
90 }
91 
92 PB_DS_CLASS_T_DEC
93 inline void
94 PB_DS_CLASS_C_DEC::
95 clear()
96 {
97  base_type::clear();
98  m_p_max = 0;
99 }
100 
101 PB_DS_CLASS_T_DEC
102 void
103 PB_DS_CLASS_C_DEC::
104 erase(point_iterator it)
105 {
106  PB_DS_ASSERT_VALID_COND((*this),true)
107  _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
108 
109  base_type::bubble_to_top(it.m_p_nd);
110  remove_parentless_node(it.m_p_nd);
111  base_type::actual_erase_node(it.m_p_nd);
112  m_p_max = 0;
113  PB_DS_ASSERT_VALID_COND((*this),true)
114 }
115 
116 PB_DS_CLASS_T_DEC
117 template<typename Pred>
118 typename PB_DS_CLASS_C_DEC::size_type
119 PB_DS_CLASS_C_DEC::
120 erase_if(Pred pred)
121 {
122  PB_DS_ASSERT_VALID_COND((*this),true)
123 
124  if (base_type::empty())
125  {
126  PB_DS_ASSERT_VALID_COND((*this),true)
127  return 0;
128  }
129 
130  base_type::to_linked_list();
131  node_pointer p_out = base_type::prune(pred);
132  size_type ersd = 0;
133  while (p_out != 0)
134  {
135  ++ersd;
136  node_pointer p_next = p_out->m_p_next_sibling;
137  base_type::actual_erase_node(p_out);
138  p_out = p_next;
139  }
140 
141  node_pointer p_cur = base_type::m_p_root;
142  base_type::m_p_root = 0;
143  while (p_cur != 0)
144  {
145  node_pointer p_next = p_cur->m_p_next_sibling;
146  p_cur->m_p_l_child = p_cur->m_p_prev_or_parent = 0;
147  p_cur->m_metadata = 0;
148  p_cur->m_p_next_sibling = base_type::m_p_root;
149 
150  if (base_type::m_p_root != 0)
151  base_type::m_p_root->m_p_prev_or_parent = p_cur;
152 
153  base_type::m_p_root = p_cur;
154  base_type::m_p_root = fix(base_type::m_p_root);
155  p_cur = p_next;
156  }
157 
158  m_p_max = 0;
159  PB_DS_ASSERT_VALID_COND((*this),true)
160  return ersd;
161 }