bst.h

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// vi:ft=cpp
/*
 * (c) 2008-2009 Alexander Warg <warg@os.inf.tu-dresden.de>,
 *               Carsten Weinhold <weinhold@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * License: see LICENSE.spdx (in this directory or the directories above)
 */
#pragma once
 
#include "../type_traits"
#include "bst_base.h"
#include "bst_iter.h"
 
struct Avl_set_tester;
 
namespace cxx { namespace Bits {

template< typename Node, typename Get_key, typename Compare >
class Bst
{
  friend struct ::Avl_set_tester;
 
private:
  typedef Direction Dir;

  struct Fwd
  {
    static Node *child(Node const *n, Direction d)
    { return Bst_node::next<Node>(n, d); }
 
    static bool cmp(Node const *l, Node const *r)
    { return Compare()(Get_key::key_of(l), Get_key::key_of(r)); }
  };

  struct Rev
  {
    static Node *child(Node const *n, Direction d)
    { return Bst_node::next<Node>(n, !d); }
 
    static bool cmp(Node const *l, Node const *r)
    { return Compare()(Get_key::key_of(r), Get_key::key_of(l)); }
  };
 
public:
  typedef typename Get_key::Key_type Key_type;
  typedef typename Type_traits<Key_type>::Param_type Key_param_type;

  typedef Fwd Fwd_iter_ops;
  typedef Rev Rev_iter_ops;


  typedef __Bst_iter<Node, Node, Fwd> Iterator;
  typedef __Bst_iter<Node, Node const, Fwd> Const_iterator;
  typedef __Bst_iter<Node, Node, Rev> Rev_iterator;
  typedef __Bst_iter<Node, Node const, Rev> Const_rev_iterator;
 
protected:

  Bst_node *_head;

  Bst() : _head(0) {}

  Node *head() const { return static_cast<Node*>(_head); }

  static Key_type k(Bst_node const *n)
  { return Get_key::key_of(static_cast<Node const *>(n)); }

  static Dir dir(Key_param_type l, Key_param_type r)
  {
    Compare cmp;
    Dir d(cmp(r, l));
    if (d == Direction::L && !cmp(l, r))
      return Direction::N;
    return d;
  }

  static Dir dir(Key_param_type l, Bst_node const *r)
  { return dir(l, k(r)); }

  static bool greater(Key_param_type l, Key_param_type r)
  { return Compare()(r, l); }

  static bool greater(Key_param_type l, Bst_node const *r)
  { return greater(l, k(r)); }

  static bool greater(Bst_node const *l, Bst_node const *r)
  { return greater(k(l), k(r)); }


  template<typename FUNC>
  static void remove_tree(Bst_node *head, FUNC &&callback)
  {
    if (Bst_node *n = Bst_node::next(head, Dir::L))
      remove_tree(n, callback);
 
    if (Bst_node *n = Bst_node::next(head, Dir::R))
      remove_tree(n, callback);
 
    callback(static_cast<Node *>(head));
  }
 
public:

  Const_iterator begin() const { return Const_iterator(head()); }
  Const_iterator end() const { return Const_iterator(); }

  Iterator begin() { return Iterator(head()); }
  Iterator end() { return Iterator(); }

  Const_rev_iterator rbegin() const { return Const_rev_iterator(head()); }
  Const_rev_iterator rend() const { return Const_rev_iterator(); }

  Rev_iterator rbegin() { return Rev_iterator(head()); }
  Rev_iterator rend() { return Rev_iterator(); }
 


  Node *find_node(Key_param_type key) const;

  Node *lower_bound_node(Key_param_type key) const;

  Const_iterator find(Key_param_type key) const;

  template<typename FUNC>
  void remove_all(FUNC &&callback)
  {
    if (!_head)
      return;
 
    Bst_node *head = _head;
    _head = 0;
    remove_tree(head, cxx::forward<FUNC>(callback));
  }
 

};
 
/* find an element */
template< typename Node, typename Get_key, class Compare>
inline
Node *
Bst<Node, Get_key, Compare>::find_node(Key_param_type key) const
{
  Dir d;
 
  for (Bst_node *q = _head; q; q = Bst_node::next(q, d))
    {
      d = dir(key, q);
      if (d == Dir::N)
  return static_cast<Node*>(q);
    }
  return 0;
}
 
template< typename Node, typename Get_key, class Compare>
inline
Node *
Bst<Node, Get_key, Compare>::lower_bound_node(Key_param_type key) const
{
  Dir d;
  Bst_node *r = 0;
 
  for (Bst_node *q = _head; q; q = Bst_node::next(q, d))
    {
      d = dir(key, q);
      if (d == Dir::L)
  r = q; // found a node greater than key
      else if (d == Dir::N)
  return static_cast<Node*>(q);
    }
  return static_cast<Node*>(r);
}
 
/* find an element */
template< typename Node, typename Get_key, class Compare>
inline
typename Bst<Node, Get_key, Compare>::Const_iterator
Bst<Node, Get_key, Compare>::find(Key_param_type key) const
{
  Bst_node *q = _head;
  Bst_node *r = q;
 
  for (Dir d; q; q = Bst_node::next(q, d))
    {
      d = dir(key, q);
      if (d == Dir::N)
  return Iterator(static_cast<Node*>(q), static_cast<Node *>(r));
 
      if (d != Dir::L && q == r)
  r = Bst_node::next(q, d);
    }
  return Iterator();
}
 
}}