libstdc++-v3/include/ext/pb_ds/priority_queue.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2024 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 priority_queue.hpp
  38  * Contains priority_queues.
  39  */
  40
  41 #ifndef PB_DS_PRIORITY_QUEUE_HPP
  42 #define PB_DS_PRIORITY_QUEUE_HPP
  43
  44 #include <bits/c++config.h>
  45 #include <ext/pb_ds/tag_and_trait.hpp>
  46 #include <ext/pb_ds/detail/priority_queue_base_dispatch.hpp>
  47 #include <ext/pb_ds/detail/standard_policies.hpp>
  48
  49 namespace __gnu_pbds
  50 {
  51   /**
  52    *  @defgroup heap-based Heap-Based
  53    *  @ingroup containers-pbds
  54    *
  55    *  @{
  56    */
  57
  58   /**
  59    *  @defgroup heap-detail Base and Policy Classes
  60    *  @ingroup heap-based
  61    */
  62
  63   /**
  64    *  A priority queue composed of one specific heap policy.
  65    *
  66    *  @tparam _Tv               Value type.
  67    *  @tparam Cmp_Fn            Comparison functor.
  68    *  @tparam Tag               Instantiating data structure type,
  69    *                            see container_tag.
  70    *  @tparam _Alloc            Allocator type.
  71    *
  72    *  Base is dispatched at compile time via Tag, from the following
  73    *  choices: binary_heap_tag, binomial_heap_tag, pairing_heap_tag,
  74    *           rc_binomial_heap_tag, thin_heap_tag
  75    *
  76    *  Base choices are: detail::binary_heap, detail::binomial_heap,
  77    *                    detail::pairing_heap, detail::rc_binomial_heap,
  78    *                    detail::thin_heap.
  79    */
  80    template<typename _Tv,
  81            typename Cmp_Fn = std::less<_Tv>,
  82            typename Tag = pairing_heap_tag,
  83            typename _Alloc = std::allocator<char> >
  84   class priority_queue
  85   : public detail::container_base_dispatch<_Tv, Cmp_Fn, _Alloc, Tag>::type
  86   {
  87   public:
  88     typedef _Tv                                         value_type;
  89     typedef Cmp_Fn                                      cmp_fn;
  90     typedef Tag                                         container_category;
  91     typedef _Alloc                                      allocator_type;
  92     typedef typename allocator_type::size_type          size_type;
  93     typedef typename allocator_type::difference_type    difference_type;
  94
  95   private:
  96     typedef typename detail::container_base_dispatch<_Tv, Cmp_Fn, _Alloc,
  97                                                      Tag>::type
  98                                                         base_type;
  99     typedef detail::rebind_traits<_Alloc, _Tv>          __rebind_va;
 100
 101  public:
 102     typedef typename __rebind_va::reference             reference;
 103     typedef typename __rebind_va::const_reference       const_reference;
 104     typedef typename __rebind_va::pointer               pointer;
 105     typedef typename __rebind_va::const_pointer         const_pointer;
 106
 107     typedef typename base_type::point_iterator          point_iterator;
 108     typedef typename base_type::point_const_iterator    point_const_iterator;
 109     typedef typename base_type::iterator                iterator;
 110     typedef typename base_type::const_iterator          const_iterator;
 111
 112     priority_queue() { }
 113
 114     /// Constructor taking some policy objects. r_cmp_fn will be
 115     /// copied by the Cmp_Fn object of the container object.
 116     priority_queue(const cmp_fn& r_cmp_fn) : base_type(r_cmp_fn) { }
 117
 118     /// Constructor taking __iterators to a range of value_types. The
 119     /// value_types between first_it and last_it will be inserted into
 120     /// the container object.
 121     template<typename It>
 122     priority_queue(It first_it, It last_it)
 123     { base_type::copy_from_range(first_it, last_it); }
 124
 125     /// Constructor taking __iterators to a range of value_types and
 126     /// some policy objects The value_types between first_it and
 127     /// last_it will be inserted into the container object. r_cmp_fn
 128     /// will be copied by the cmp_fn object of the container object.
 129     template<typename It>
 130     priority_queue(It first_it, It last_it, const cmp_fn& r_cmp_fn)
 131     : base_type(r_cmp_fn)
 132     { base_type::copy_from_range(first_it, last_it); }
 133
 134     priority_queue(const priority_queue& other)
 135     : base_type((const base_type& )other) { }
 136
 137     virtual
 138     ~priority_queue() { }
 139
 140     priority_queue&
 141     operator=(const priority_queue& other)
 142     {
 143       if (this != &other)
 144         {
 145           priority_queue tmp(other);
 146           swap(tmp);
 147         }
 148       return *this;
 149     }
 150
 151     void
 152     swap(priority_queue& other)
 153     { base_type::swap(other); }
 154   };
 155  ///@} heap-based
 156 } // namespace __gnu_pbds
 157 #endif