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

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2009 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 pairing heap.
  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();)
  47   _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
  48
  49   node_pointer p_new_root = join_node_children(base_type::m_p_root);
  50   _GLIBCXX_DEBUG_ONLY(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   _GLIBCXX_DEBUG_ONLY(assert_valid();)
  57 }
  58
  59 PB_DS_CLASS_T_DEC
  60 void
  61 PB_DS_CLASS_C_DEC::
  62 erase(point_iterator it)
  63 {
  64   _GLIBCXX_DEBUG_ONLY(assert_valid();)
  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   _GLIBCXX_DEBUG_ONLY(assert_valid();)
  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   _GLIBCXX_DEBUG_ONLY(assert_valid();)
  77   _GLIBCXX_DEBUG_ASSERT(!base_type::empty());
  78   node_pointer p_new_child = join_node_children(p_nd);
  79
  80 #ifdef _GLIBCXX_DEBUG
  81   if (p_new_child != 0)
  82     base_type::assert_node_consistent(p_new_child, false);
  83 #endif
  84
  85   if (p_nd == base_type::m_p_root)
  86     {
  87       if (p_new_child != 0)
  88         p_new_child->m_p_prev_or_parent = 0;
  89       base_type::m_p_root = p_new_child;
  90       _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(base_type::m_p_root, false);)
  91       return;
  92     }
  93
  94   _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_prev_or_parent != 0);
  95   if (p_nd->m_p_prev_or_parent->m_p_l_child == p_nd)
  96     {
  97       if (p_new_child != 0)
  98         {
  99           p_new_child->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
 100           p_new_child->m_p_next_sibling = p_nd->m_p_next_sibling;
 101           if (p_new_child->m_p_next_sibling != 0)
 102             p_new_child->m_p_next_sibling->m_p_prev_or_parent = p_new_child;
 103           p_nd->m_p_prev_or_parent->m_p_l_child = p_new_child;
 104           _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd->m_p_prev_or_parent, false);)
 105           return;
 106         }
 107
 108       p_nd->m_p_prev_or_parent->m_p_l_child = p_nd->m_p_next_sibling;
 109       if (p_nd->m_p_next_sibling != 0)
 110         p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
 111       _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd->m_p_prev_or_parent, false);)
 112       return;
 113     }
 114
 115   if (p_new_child != 0)
 116     {
 117       p_new_child->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
 118       p_new_child->m_p_next_sibling = p_nd->m_p_next_sibling;
 119       if (p_new_child->m_p_next_sibling != 0)
 120         p_new_child->m_p_next_sibling->m_p_prev_or_parent = p_new_child;
 121       p_new_child->m_p_prev_or_parent->m_p_next_sibling = p_new_child;
 122       _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd->m_p_prev_or_parent, false);)
 123       return;
 124     }
 125
 126   p_nd->m_p_prev_or_parent->m_p_next_sibling = p_nd->m_p_next_sibling;
 127   if (p_nd->m_p_next_sibling != 0)
 128     p_nd->m_p_next_sibling->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
 129   _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd->m_p_prev_or_parent, false);)
 130 }
 131
 132 PB_DS_CLASS_T_DEC
 133 typename PB_DS_CLASS_C_DEC::node_pointer
 134 PB_DS_CLASS_C_DEC::
 135 join_node_children(node_pointer p_nd)
 136 {
 137   _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
 138   node_pointer p_ret = p_nd->m_p_l_child;
 139   if (p_ret == 0)
 140     return 0;
 141   while (p_ret->m_p_next_sibling != 0)
 142     p_ret = forward_join(p_ret, p_ret->m_p_next_sibling);
 143   while (p_ret->m_p_prev_or_parent != p_nd)
 144     p_ret = back_join(p_ret->m_p_prev_or_parent, p_ret);
 145   _GLIBCXX_DEBUG_ONLY(assert_node_consistent(p_ret, false);)
 146   return p_ret;
 147 }
 148
 149 PB_DS_CLASS_T_DEC
 150 typename PB_DS_CLASS_C_DEC::node_pointer
 151 PB_DS_CLASS_C_DEC::
 152 forward_join(node_pointer p_nd, node_pointer p_next)
 153 {
 154   _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
 155   _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_next_sibling == p_next);
 156   if (Cmp_Fn::operator()(p_nd->m_value, p_next->m_value))
 157     {
 158       p_next->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
 159       base_type::make_child_of(p_nd, p_next);
 160       return p_next->m_p_next_sibling == 0
 161         ? p_next : p_next->m_p_next_sibling;
 162     }
 163
 164   if (p_next->m_p_next_sibling != 0)
 165     {
 166       p_next->m_p_next_sibling->m_p_prev_or_parent = p_nd;
 167       p_nd->m_p_next_sibling = p_next->m_p_next_sibling;
 168       base_type::make_child_of(p_next, p_nd);
 169       return p_nd->m_p_next_sibling;
 170     }
 171
 172   p_nd->m_p_next_sibling = 0;
 173   base_type::make_child_of(p_next, p_nd);
 174   _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd, false));
 175   return p_nd;
 176 }
 177
 178 PB_DS_CLASS_T_DEC
 179 typename PB_DS_CLASS_C_DEC::node_pointer
 180 PB_DS_CLASS_C_DEC::
 181 back_join(node_pointer p_nd, node_pointer p_next)
 182 {
 183   _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
 184   _GLIBCXX_DEBUG_ASSERT(p_next->m_p_next_sibling == 0);
 185
 186   if (Cmp_Fn::operator()(p_nd->m_value, p_next->m_value))
 187     {
 188       p_next->m_p_prev_or_parent = p_nd->m_p_prev_or_parent;
 189       base_type::make_child_of(p_nd, p_next);
 190       _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_next, false));
 191       return p_next;
 192     }
 193
 194   p_nd->m_p_next_sibling = 0;
 195   base_type::make_child_of(p_next, p_nd);
 196   _GLIBCXX_DEBUG_ONLY(base_type::assert_node_consistent(p_nd, false));
 197   return p_nd;
 198 }
 199
 200 PB_DS_CLASS_T_DEC
 201 template<typename Pred>
 202 typename PB_DS_CLASS_C_DEC::size_type
 203 PB_DS_CLASS_C_DEC::
 204 erase_if(Pred pred)
 205 {
 206   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 207     if (base_type::empty())
 208       {
 209         _GLIBCXX_DEBUG_ONLY(assert_valid();)
 210         return 0;
 211       }
 212   base_type::to_linked_list();
 213   node_pointer p_out = base_type::prune(pred);
 214   size_type ersd = 0;
 215   while (p_out != 0)
 216     {
 217       ++ersd;
 218       node_pointer p_next = p_out->m_p_next_sibling;
 219       base_type::actual_erase_node(p_out);
 220       p_out = p_next;
 221     }
 222
 223   node_pointer p_cur = base_type::m_p_root;
 224   base_type::m_p_root = 0;
 225   while (p_cur != 0)
 226     {
 227       node_pointer p_next = p_cur->m_p_next_sibling;
 228       p_cur->m_p_l_child = p_cur->m_p_next_sibling = p_cur->m_p_prev_or_parent = 0;
 229
 230       push_imp(p_cur);
 231       p_cur = p_next;
 232     }
 233   _GLIBCXX_DEBUG_ONLY(assert_valid();)
 234   return ersd;
 235 }
 236