contrib/gcc-8.0/libstdc++-v3/include/ext/pb_ds/detail/pairing_heap_/erase_fn_imps.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2018 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
  41 PB_DS_CLASS_T_DEC
  42 void
  43 PB_DS_CLASS_C_DEC::
  44 pop()
  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
  59 PB_DS_CLASS_T_DEC
  60 void
  61 PB_DS_CLASS_C_DEC::
  62 erase(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
  71 PB_DS_CLASS_T_DEC
  72 void
  73 PB_DS_CLASS_C_DEC::
  74 remove_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
 129 PB_DS_CLASS_T_DEC
 130 typename PB_DS_CLASS_C_DEC::node_pointer
 131 PB_DS_CLASS_C_DEC::
 132 join_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
 146 PB_DS_CLASS_T_DEC
 147 typename PB_DS_CLASS_C_DEC::node_pointer
 148 PB_DS_CLASS_C_DEC::
 149 forward_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
 175 PB_DS_CLASS_T_DEC
 176 typename PB_DS_CLASS_C_DEC::node_pointer
 177 PB_DS_CLASS_C_DEC::
 178 back_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
 197 PB_DS_CLASS_T_DEC
 198 template<typename Pred>
 199 typename PB_DS_CLASS_C_DEC::size_type
 200 PB_DS_CLASS_C_DEC::
 201 erase_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