tree_policy.hpp

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// -*- C++ -*-
 
// Copyright (C) 2005-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License as published by the Free Software
// Foundation; either version 3, or (at your option) any later
// version.
 
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
 
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
 
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.
 
// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
 
// Permission to use, copy, modify, sell, and distribute this software
// is hereby granted without fee, provided that the above copyright
// notice appears in all copies, and that both that copyright notice
// and this permission notice appear in supporting documentation. None
// of the above authors, nor IBM Haifa Research Laboratories, make any
// representation about the suitability of this software for any
// purpose. It is provided "as is" without express or implied
// warranty.
 
/**
 * @file tree_policy.hpp
 * Contains tree-related policies.
 */
 
#ifndef PB_DS_TREE_POLICY_HPP
#define PB_DS_TREE_POLICY_HPP
 
#include <bits/c++config.h>
#include <iterator>
#include <ext/pb_ds/detail/type_utils.hpp>
#include <ext/pb_ds/detail/branch_policy/branch_policy.hpp>
 
namespace __gnu_pbds
{
#define PB_DS_CLASS_T_DEC \
  template<typename Node_CItr, typename Node_Itr, typename Cmp_Fn, \
           typename _Alloc>
 
#define PB_DS_CLASS_C_DEC \
  tree_order_statistics_node_update<Node_CItr, Node_Itr, Cmp_Fn, _Alloc>
 
#define PB_DS_BRANCH_POLICY_BASE \
  detail::branch_policy<Node_CItr, Node_Itr, _Alloc>
 
  /// Functor updating ranks of entrees.
  template<typename Node_CItr, typename Node_Itr, 
           typename Cmp_Fn, typename _Alloc>
  class tree_order_statistics_node_update : private PB_DS_BRANCH_POLICY_BASE
  {
  private:
    typedef PB_DS_BRANCH_POLICY_BASE                    base_type;
 
  public:
    typedef Cmp_Fn                                      cmp_fn;
    typedef _Alloc                                      allocator_type;
    typedef typename allocator_type::size_type          size_type;
    typedef typename base_type::key_type                key_type;
    typedef typename base_type::key_const_reference     key_const_reference;
 
    typedef size_type                                   metadata_type;
    typedef Node_CItr                           node_const_iterator;
    typedef Node_Itr                                    node_iterator;
    typedef typename node_const_iterator::value_type    const_iterator;
    typedef typename node_iterator::value_type          iterator;
 
    /// Finds an entry by __order. Returns a const_iterator to the
    /// entry with the __order order, or a const_iterator to the
    /// container object's end if order is at least the size of the
    /// container object.
    inline const_iterator
    find_by_order(size_type) const;
 
    /// Finds an entry by __order. Returns an iterator to the entry
    /// with the __order order, or an iterator to the container
    /// object's end if order is at least the size of the container
    /// object.
    inline iterator
    find_by_order(size_type);
 
    /// Returns the order of a key within a sequence. For exapmle, if
    /// r_key is the smallest key, this method will return 0; if r_key
    /// is a key between the smallest and next key, this method will
    /// return 1; if r_key is a key larger than the largest key, this
    /// method will return the size of r_c.
    inline size_type
    order_of_key(key_const_reference) const;
 
  private:
    /// Const reference to the container's value-type.
    typedef typename base_type::const_reference         const_reference;
 
    /// Const pointer to the container's value-type.
    typedef typename base_type::const_pointer           const_pointer;
 
    /// Const metadata reference.
    typedef typename detail::rebind_traits<_Alloc, metadata_type>::const_reference
      metadata_const_reference;
 
    /// Metadata reference.
    typedef typename detail::rebind_traits<_Alloc, metadata_type>::reference
      metadata_reference;
 
    /// Returns the node_const_iterator associated with the tree's root node.
    virtual node_const_iterator
    node_begin() const = 0;
 
    /// Returns the node_iterator associated with the tree's root node.
    virtual node_iterator
    node_begin() = 0;
 
    /// Returns the node_const_iterator associated with a just-after leaf node.
    virtual node_const_iterator
    node_end() const = 0;
 
    /// Returns the node_iterator associated with a just-after leaf node.
    virtual node_iterator
    node_end() = 0;
 
    /// Access to the cmp_fn object.
    virtual cmp_fn& 
    get_cmp_fn() = 0;
 
  protected:
    /// Updates the rank of a node through a node_iterator node_it;
    /// end_nd_it is the end node iterator.
    inline void
    operator()(node_iterator, node_const_iterator) const;
 
    virtual
    ~tree_order_statistics_node_update();
  };
 
#include <ext/pb_ds/detail/tree_policy/order_statistics_imp.hpp>
 
#undef PB_DS_CLASS_T_DEC
#undef PB_DS_CLASS_C_DEC
#undef PB_DS_BRANCH_POLICY_BASE
 
} // namespace __gnu_pbds
 
#endif