rbNodeRk.H

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/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
 
 
# ifndef RBNODERK_H
# define RBNODERK_H
 
# include <tpl_binNode.H>
 
namespace Aleph {
 
typedef unsigned char Color;
# define COLOR(p) ((p)->getColor())
# define RED      (0)
# define BLACK    (1)
 
class RbNodeRk_Data
{
  Color color;      // RED or BLACK
  size_t count;     // number of nodes in subtree (including this node)
 
public:
 
  RbNodeRk_Data() noexcept : color(RED), count(1) { /* empty */ }
 
  RbNodeRk_Data(SentinelCtor) noexcept : color(BLACK), count(0) { /* empty */ }
 
  Color & getColor() noexcept { return color; }
 
  size_t & getCount() noexcept { return count; }
 
  void reset() noexcept
  {
    color = RED;
    count = 1;
  }
};
 
DECLARE_BINNODE_SENTINEL(RbNodeRk, 128, RbNodeRk_Data);
 
 
template <class Node>
bool test_black_condition_rk(Node *p, int &max, int bh = 0)
{
  if (p == Node::NullPtr)
    return true;
 
  if (COLOR(p) == BLACK)
    bh++;
 
  if (LLINK(p) == Node::NullPtr and RLINK(p) == Node::NullPtr)
    {
      if (max == -1)
        max = bh;
 
      return bh == max;
    }
 
  return test_black_condition_rk(LLINK(p), max, bh) and
         test_black_condition_rk(RLINK(p), max, bh);
}
 
template <class Node>
bool is_red_black_rk(Node * node)
{
  if (node == Node::NullPtr)
    return true;
 
  if (not (COLOR(node) == RED or COLOR(node) == BLACK))
    return false;
 
  if (COLOR(node) == RED)
    if (COLOR(LLINK(node)) == RED or COLOR(RLINK(node)) == RED)
      return false;
 
  int max = -1;
 
  return test_black_condition_rk(node, max, 0);
}
 
template <class Node>
bool is_red_black_tree_rk(Node * node)
{
  if (node == Node::NullPtr)
    return true;
 
  // Check counter
  if (node->getCount() != LLINK(node)->getCount() + RLINK(node)->getCount() + 1)
    return false;
 
  if (not is_red_black_rk(node))
    return false;
 
  if (not is_red_black_tree_rk(LLINK(node)) or
      not is_red_black_tree_rk(RLINK(node)))
    return false;
 
  return true;
}
 
template <class Node, class Compare>
bool is_red_black_bst_rk(Node * node, Compare & cmp)
{
  if (not is_red_black_tree_rk(node))
    return false;
 
  return check_bst(node, cmp);
}
 
} // end namespace Aleph
 
# endif // RBNODERK_H