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

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2020 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 binomial_heap_base_/erase_fn_imps.hpp
  38  * Contains an implementation class for a base of binomial heaps.
  39  */
  40
  41 #ifdef PB_DS_CLASS_C_DEC
  42
  43 PB_DS_CLASS_T_DEC
  44 void
  45 PB_DS_CLASS_C_DEC::
  46 pop()
  47 {
  48   PB_DS_ASSERT_VALID_COND((*this),true)
  49   _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
  50
  51   if (m_p_max == 0)
  52     find_max();
  53
  54   _GLIBCXX_DEBUG_ASSERT(m_p_max != 0);
  55   node_pointer p_nd = m_p_max;
  56   remove_parentless_node(m_p_max);
  57   base_type::actual_erase_node(p_nd);
  58   m_p_max = 0;
  59   PB_DS_ASSERT_VALID_COND((*this),true)
  60 }
  61
  62 PB_DS_CLASS_T_DEC
  63 void
  64 PB_DS_CLASS_C_DEC::
  65 remove_parentless_node(node_pointer p_nd)
  66 {
  67   _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
  68   _GLIBCXX_DEBUG_ASSERT(base_type::parent(p_nd) == 0);
  69
  70   node_pointer p_cur_root = p_nd == base_type::m_p_root?
  71     p_nd->m_p_next_sibling : base_type::m_p_root;
  72
  73   if (p_cur_root != 0)
  74     p_cur_root->m_p_prev_or_parent = 0;
  75
  76   if (p_nd->m_p_prev_or_parent != 0)
  77     p_nd->m_p_prev_or_parent->m_p_next_sibling = p_nd->m_p_next_sibling;
  78
  79   if (p_nd->m_p_next_sibling != 0)
  80     p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
  81
  82   node_pointer p_child = p_nd->m_p_l_child;
  83   if (p_child != 0)
  84     {
  85       p_child->m_p_prev_or_parent = 0;
  86       while (p_child->m_p_next_sibling != 0)
  87         p_child = p_child->m_p_next_sibling;
  88     }
  89
  90   m_p_max = 0;
  91   base_type::m_p_root = join(p_cur_root, p_child);
  92 }
  93
  94 PB_DS_CLASS_T_DEC
  95 inline void
  96 PB_DS_CLASS_C_DEC::
  97 clear()
  98 {
  99   base_type::clear();
 100   m_p_max = 0;
 101 }
 102
 103 PB_DS_CLASS_T_DEC
 104 void
 105 PB_DS_CLASS_C_DEC::
 106 erase(point_iterator it)
 107 {
 108   PB_DS_ASSERT_VALID_COND((*this),true)
 109   _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
 110
 111   base_type::bubble_to_top(it.m_p_nd);
 112   remove_parentless_node(it.m_p_nd);
 113   base_type::actual_erase_node(it.m_p_nd);
 114   m_p_max = 0;
 115   PB_DS_ASSERT_VALID_COND((*this),true)
 116 }
 117
 118 PB_DS_CLASS_T_DEC
 119 template<typename Pred>
 120 typename PB_DS_CLASS_C_DEC::size_type
 121 PB_DS_CLASS_C_DEC::
 122 erase_if(Pred pred)
 123 {
 124   PB_DS_ASSERT_VALID_COND((*this),true)
 125
 126   if (base_type::empty())
 127     {
 128       PB_DS_ASSERT_VALID_COND((*this),true)
 129       return 0;
 130     }
 131
 132   base_type::to_linked_list();
 133   node_pointer p_out = base_type::prune(pred);
 134   size_type ersd = 0;
 135   while (p_out != 0)
 136     {
 137       ++ersd;
 138       node_pointer p_next = p_out->m_p_next_sibling;
 139       base_type::actual_erase_node(p_out);
 140       p_out = p_next;
 141     }
 142
 143   node_pointer p_cur = base_type::m_p_root;
 144   base_type::m_p_root = 0;
 145   while (p_cur != 0)
 146     {
 147       node_pointer p_next = p_cur->m_p_next_sibling;
 148       p_cur->m_p_l_child = p_cur->m_p_prev_or_parent = 0;
 149       p_cur->m_metadata = 0;
 150       p_cur->m_p_next_sibling = base_type::m_p_root;
 151
 152       if (base_type::m_p_root != 0)
 153         base_type::m_p_root->m_p_prev_or_parent = p_cur;
 154
 155       base_type::m_p_root = p_cur;
 156       base_type::m_p_root = fix(base_type::m_p_root);
 157       p_cur = p_next;
 158     }
 159
 160   m_p_max = 0;
 161   PB_DS_ASSERT_VALID_COND((*this),true)
 162   return ersd;
 163 }
 164 #endif