libstdc++-v3/include/ext/pb_ds/detail/binomial_heap_base_/erase_fn_imps.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2009, 2010 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 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   _GLIBCXX_DEBUG_ONLY(assert_valid(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
  54   node_pointer p_nd = m_p_max;
  55
  56   remove_parentless_node(m_p_max);
  57
  58   base_type::actual_erase_node(p_nd);
  59
  60   m_p_max = 0;
  61
  62   _GLIBCXX_DEBUG_ONLY(assert_valid(true);)
  63     }
  64
  65 PB_DS_CLASS_T_DEC
  66 void
  67 PB_DS_CLASS_C_DEC::
  68 remove_parentless_node(node_pointer p_nd)
  69 {
  70   _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
  71   _GLIBCXX_DEBUG_ASSERT(base_type::parent(p_nd) == 0);
  72
  73   node_pointer p_cur_root = p_nd == base_type::m_p_root?
  74     p_nd->m_p_next_sibling :
  75     base_type::m_p_root;
  76
  77   if (p_cur_root != 0)
  78     p_cur_root->m_p_prev_or_parent = 0;
  79
  80   if (p_nd->m_p_prev_or_parent != 0)
  81     p_nd->m_p_prev_or_parent->m_p_next_sibling = p_nd->m_p_next_sibling;
  82
  83   if (p_nd->m_p_next_sibling != 0)
  84     p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
  85
  86   node_pointer p_child = p_nd->m_p_l_child;
  87
  88   if (p_child != 0)
  89     {
  90       p_child->m_p_prev_or_parent = 0;
  91
  92       while (p_child->m_p_next_sibling != 0)
  93         p_child = p_child->m_p_next_sibling;
  94     }
  95
  96   m_p_max = 0;
  97
  98   base_type::m_p_root = join(p_cur_root, p_child);
  99 }
 100
 101 PB_DS_CLASS_T_DEC
 102 inline void
 103 PB_DS_CLASS_C_DEC::
 104 clear()
 105 {
 106   base_type::clear();
 107
 108   m_p_max = 0;
 109 }
 110
 111 PB_DS_CLASS_T_DEC
 112 void
 113 PB_DS_CLASS_C_DEC::
 114 erase(point_iterator it)
 115 {
 116   _GLIBCXX_DEBUG_ONLY(assert_valid(true);)
 117     _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
 118
 119   base_type::bubble_to_top(it.m_p_nd);
 120
 121   remove_parentless_node(it.m_p_nd);
 122
 123   base_type::actual_erase_node(it.m_p_nd);
 124
 125   m_p_max = 0;
 126
 127   _GLIBCXX_DEBUG_ONLY(assert_valid(true);)
 128     }
 129
 130 PB_DS_CLASS_T_DEC
 131 template<typename Pred>
 132 typename PB_DS_CLASS_C_DEC::size_type
 133 PB_DS_CLASS_C_DEC::
 134 erase_if(Pred pred)
 135 {
 136   _GLIBCXX_DEBUG_ONLY(assert_valid(true);)
 137
 138     if (base_type::empty())
 139       {
 140         _GLIBCXX_DEBUG_ONLY(assert_valid(true);)
 141
 142           return 0;
 143       }
 144
 145   base_type::to_linked_list();
 146
 147   node_pointer p_out = base_type::prune(pred);
 148
 149   size_type ersd = 0;
 150
 151   while (p_out != 0)
 152     {
 153       ++ersd;
 154
 155       node_pointer p_next = p_out->m_p_next_sibling;
 156
 157       base_type::actual_erase_node(p_out);
 158
 159       p_out = p_next;
 160     }
 161
 162   node_pointer p_cur = base_type::m_p_root;
 163
 164   base_type::m_p_root = 0;
 165
 166   while (p_cur != 0)
 167     {
 168       node_pointer p_next = p_cur->m_p_next_sibling;
 169
 170       p_cur->m_p_l_child = p_cur->m_p_prev_or_parent = 0;
 171
 172       p_cur->m_metadata = 0;
 173
 174       p_cur->m_p_next_sibling = base_type::m_p_root;
 175
 176       if (base_type::m_p_root != 0)
 177         base_type::m_p_root->m_p_prev_or_parent = p_cur;
 178
 179       base_type::m_p_root = p_cur;
 180
 181       base_type::m_p_root = fix(base_type::m_p_root);
 182
 183       p_cur = p_next;
 184     }
 185
 186   m_p_max = 0;
 187
 188   _GLIBCXX_DEBUG_ONLY(assert_valid(true);)
 189
 190     return ersd;
 191 }
 192