priority_queue.hpp

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// -*- C++ -*-

// Copyright (C) 2005, 2006, 2009, 2010 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
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// warranty.

/**
 * @file priority_queue.hpp
 * Contains priority_queues.
 */

#ifndef PB_DS_PRIORITY_QUEUE_HPP
#define PB_DS_PRIORITY_QUEUE_HPP

#include <bits/c++config.h>
#include <ext/pb_ds/tag_and_trait.hpp>
#include <ext/pb_ds/detail/priority_queue_base_dispatch.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>

namespace __gnu_pbds
{
  // A priority queue.
  template<typename Value_Type, 
       typename Cmp_Fn = std::less<Value_Type>,
       typename Tag = pairing_heap_tag,
       typename Allocator = std::allocator<char> >
  class priority_queue 
  : public detail::priority_queue_base_dispatch<Value_Type,
                        Cmp_Fn,Tag,Allocator>::type
  {
  private:
    typedef typename
    detail::priority_queue_base_dispatch<Value_Type, Cmp_Fn,
                     Tag, Allocator>::type base_type;

  public:
    typedef Value_Type                  value_type;
    typedef Cmp_Fn                  cmp_fn;
    typedef Tag                     container_category;
    typedef Allocator                   allocator_type;
    typedef typename allocator_type::size_type      size_type;
    typedef typename allocator_type::difference_type    difference_type;

    typedef typename allocator_type::template rebind<value_type>::other value_rebind;
    typedef typename value_rebind::reference        reference;
    typedef typename value_rebind::const_reference  const_reference;
    typedef typename value_rebind::pointer      pointer;
    typedef typename value_rebind::const_pointer    const_pointer;

    typedef typename base_type::const_point_iterator const_point_iterator;
    typedef typename base_type::point_iterator      point_iterator;
    typedef typename base_type::const_iterator      const_iterator;
    typedef typename base_type::iterator        iterator;

    priority_queue() { }

    // Constructor taking some policy objects. r_cmp_fn will be copied
    // by the Cmp_Fn object of the container object.
    priority_queue(const cmp_fn& r_cmp_fn) : base_type(r_cmp_fn) { }

    // Constructor taking __iterators to a range of value_types. The
    // value_types between first_it and last_it will be inserted into
    // the container object.
    template<typename It>
    priority_queue(It first_it, It last_it)
    { base_type::copy_from_range(first_it, last_it); }

    // Constructor taking __iterators to a range of value_types and
    // some policy objects The value_types between first_it and
    // last_it will be inserted into the container object. r_cmp_fn
    // will be copied by the cmp_fn object of the container object.
    template<typename It>
    priority_queue(It first_it, It last_it, const cmp_fn& r_cmp_fn)
    : base_type(r_cmp_fn)
    { base_type::copy_from_range(first_it, last_it); }

    priority_queue(const priority_queue& other)
    : base_type((const base_type& )other) { }

    virtual
    ~priority_queue() { }

    priority_queue& 
    operator=(const priority_queue& other)
    {
      if (this != &other)
    {
      priority_queue tmp(other);
      swap(tmp);
    }
      return *this;
    }

    void
    swap(priority_queue& other)
    { base_type::swap(other); }
  };
} // namespace __gnu_pbds

#endif