ext/OGDF/ogdf/basic/HeapBase.h

   1 /*
   2  * $Revision: 2564 $
   3  *
   4  * last checkin:
   5  *   $Author:klein $
   6  *   $Date:2007-10-18 17:23:28 +0200 (Thu, 18 Oct 2007) $
   7  ***************************************************************/
   8
   9 /** \file
  10  * \brief Declaration of an abstract heap base class for
  11  * priority queue implementation.
  12  *
  13  * \author Karsten Klein
  14  *
  15  * \par License:
  16  * This file is part of the Open Graph Drawing Framework (OGDF).
  17  *
  18  * \par
  19  * Copyright (C)<br>
  20  * See README.txt in the root directory of the OGDF installation for details.
  21  *
  22  * \par
  23  * This program is free software; you can redistribute it and/or
  24  * modify it under the terms of the GNU General Public License
  25  * Version 2 or 3 as published by the Free Software Foundation;
  26  * see the file LICENSE.txt included in the packaging of this file
  27  * for details.
  28  *
  29  * \par
  30  * This program is distributed in the hope that it will be useful,
  31  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  33  * GNU General Public License for more details.
  34  *
  35  * \par
  36  * You should have received a copy of the GNU General Public
  37  * License along with this program; if not, write to the Free
  38  * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  39  * Boston, MA 02110-1301, USA.
  40  *
  41  * \see  http://www.gnu.org/copyleft/gpl.html
  42  ***************************************************************/
  43
  44
  45 #ifdef _MSC_VER
  46 #pragma once
  47 #endif
  48
  49 #ifndef OGDF_HEAP_BASE_H
  50 #define OGDF_HEAP_BASE_H
  51
  52
  53 #include <ogdf/basic/GraphCopy.h>
  54
  55
  56 namespace ogdf {
  57
  58 /**
  59
  60 * \brief A data structure implementing the abstract data type
  61 * priority queue
  62 * A Heap is a data structure implementing the abstract data type
  63 * priority queue, maintaining a set of elements each with an associated key value
  64 * used for keeping the elements in a specific order.
  65
  66 * It supports the following operations:
  67 * insert(element, key) insert element with key in set
  68 * min   return element with minimum key
  69 * extractMin   remove and return element with minimum key
  70 * decreaseKey   decrease the key of a given element to a given value
  71 * delete   remove a given element fromthe structure
  72
  73
  74 * Running times and space requirements are depending on the actual
  75 * implementation type (e.g., binary, binomial or fibonacci heaps)
  76
  77 */
  78
  79
  80 class HeapEntry;
  81
  82 class HeapEntryPointer;
  83
  84 template <class Priority, class HeapObject>
  85 class HeapBase {
  86
  87 public:
  88         //! Constructor
  89         HeapBase() { }
  90
  91         virtual ~HeapBase() { }
  92
  93
  94         //! build a heap out of a given set of elements
  95         virtual void makeHeap() = 0;
  96
  97         HeapObject minRet() { }
  98
  99         //*******************************************************
 100         //Modification
 101
 102         //! insert a new element with priority key
 103         virtual void insert(HeapObject, Priority /* key */) { }
 104         //extractMin
 105         //derived classes should decide themselves if they have
 106         //a specific delete function
 107         //virtual void delete() = 0;
 108
 109         //! update the data structure by decreasing the key of an object
 110         //TODO: Does not make much sense without an object parameter
 111         virtual void decreaseKey() { }
 112
 113         //*******************************************************
 114         //constant functions
 115         int size() const {return m_size;}
 116
 117         bool empty() const {return m_size==0;}
 118
 119
 120 protected:
 121         int m_size; //number of elements stored in heap
 122
 123 };
 124
 125
 126
 127 } //namespace ogdf
 128
 129 #endif