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      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 != NULL)
     52     p_new_root->m_p_prev_or_parent = NULL;
     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 != NULL)
     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 != NULL)
     88 	p_new_child->m_p_prev_or_parent = NULL;
     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 != NULL);
     95   if (p_nd->m_p_prev_or_parent->m_p_l_child == p_nd)
     96     {
     97       if (p_new_child != NULL)
     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 != NULL)
    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 != NULL)
    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 != NULL)
    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 != NULL)
    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 != NULL)
    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 != NULL);
    138   node_pointer p_ret = p_nd->m_p_l_child;
    139   if (p_ret == NULL)
    140     return NULL;
    141   while (p_ret->m_p_next_sibling != NULL)
    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 != NULL);
    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 == NULL
    161 	? p_next : p_next->m_p_next_sibling;
    162     }
    163 
    164   if (p_next->m_p_next_sibling != NULL)
    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 = NULL;
    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 != NULL);
    184   _GLIBCXX_DEBUG_ASSERT(p_next->m_p_next_sibling == NULL);
    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 = NULL;
    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 != NULL)
    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 = NULL;
    225   while (p_cur != NULL)
    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 = NULL;
    229 
    230       push_imp(p_cur);
    231       p_cur = p_next;
    232     }
    233   _GLIBCXX_DEBUG_ONLY(assert_valid();)
    234   return ersd;
    235 }
    236 
    237