FibonacciHeap.h

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/*********************************************************\
 *  File: FibonacciHeap.h                                *
 *
 *  Copyright (C) 2002-2012 The PixelLight Team (http://www.pixellight.org/)
 *
 *  This file is part of PixelLight.
 *
 *  PixelLight is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  PixelLight 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with PixelLight. If not, see <http://www.gnu.org/licenses/>.
\*********************************************************/


#ifndef __PLCORE_CONTAINER_FIBONACCIHEAP_H__
#define __PLCORE_CONTAINER_FIBONACCIHEAP_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include "PLCore/Container/Heap.h"
#include "PLCore/Container/Functions.h"


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLCore {


//[-------------------------------------------------------]
//[ Forward declarations                                  ]
//[-------------------------------------------------------]
template <class KeyType, class ValueType, class Comparer> class FibonacciHeapIterator;


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Fibonacci heap
*/
template <class KeyType, class ValueType, class Comparer = CompareFunction >
class FibonacciHeap : public Heap<KeyType, ValueType> {


    //[-------------------------------------------------------]
    //[ Friends                                               ]
    //[-------------------------------------------------------]
    friend class FibonacciHeapIterator<KeyType, ValueType, Comparer>;


    //[-------------------------------------------------------]
    //[ Public functions                                      ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Constructor
        */
        FibonacciHeap();

        /**
        *  @brief
        *    Destructor
        */
        virtual ~FibonacciHeap();

        /**
        *  @brief
        *    Returns whether the Fibonacci heap is normalized or not
        *
        *  @return
        *    'true' if the Fibonacci heap is normalized, else 'false'
        *
        *  @remarks
        *    A Fibonacci heap is normalized if there are no tree's within the tree list
        *    with the same degree. After 'ExtractTop()' the heap is always normalized.
        */
        bool IsNormalized();

        /**
        *  @brief
        *    Consolidate
        *
        *  @remarks
        *    'Cleanup' function. This function is called during the extraction of
        *    the top element automatically. After the execution of this function the
        *    heap is 'normalized'.
        *
        *  @return
        *    'true' if all went fine, else 'false' (maybe consolidate is not required)
        */
        bool Consolidate();


    //[-------------------------------------------------------]
    //[ Private functions                                     ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    Copy constructor
        *
        *  @param[in] cSource
        *    Source to copy from
        */
        FibonacciHeap(const FibonacciHeap<KeyType, ValueType, Comparer> &cSource);

        /**
        *  @brief
        *    Makes this heap to a copy of another heap
        *
        *  @param[in] cHeap
        *    'FibonacciHeap' to copy from
        *
        *  @return
        *    Reference to this instance
        */
        Heap<KeyType, ValueType> &operator =(const FibonacciHeap<KeyType, ValueType, Comparer> &cHeap);


    //[-------------------------------------------------------]
    //[ Private classes                                       ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    Internal Fibonacci tree
        */
        class Tree {


            //[-------------------------------------------------------]
            //[ Friends                                               ]
            //[-------------------------------------------------------]
            friend class FibonacciHeap<KeyType, ValueType, Comparer>;
            friend class FibonacciHeapIterator<KeyType, ValueType, Comparer>;


            //[-------------------------------------------------------]
            //[ Public functions                                      ]
            //[-------------------------------------------------------]
            public:
                /**
                *  @brief
                *    Constructor
                *
                *  @param[in] Key
                *    Key
                *  @param[in] Value
                *    Value
                */
                Tree(KeyType Key, ValueType Value);

                /**
                *  @brief
                *    Destructor
                */
                ~Tree();

                /**
                *  @brief
                *    Union
                *
                *  @param[in] cTree
                *    Tree to union with this tree
                */
                void Union(Tree &cTree);


            //[-------------------------------------------------------]
            //[ Private data                                          ]
            //[-------------------------------------------------------]
            private:
                uint32     m_nDegree;           /**< Degree of this tree node */
                Tree      *m_pPreviousSibling;  /**< Previous sibling tree, can be a null pointer */
                Tree      *m_pNextSibling;      /**< Next sibling tree, can be a null pointer */
                Tree      *m_pChild;            /**< Child tree, can be a null pointer */
                KeyType    m_Key;               /**< Key of this tree node */
                ValueType  m_Value;             /**< Value of this tree node */


        };


    //[-------------------------------------------------------]
    //[ Private data                                          ]
    //[-------------------------------------------------------]
    private:
        // General data
        uint32   m_nNumOfElements;  /**< Current number of elements */
        Tree    *m_pFirst;          /**< First Fibonacci tree, can be a null pointer */
        Tree    *m_pTop;            /**< The current top Fibonacci tree, can be a null pointer (smallest/greatest key) */
        // Data for cleanup
        uint32   m_nNumOfTrees;     /**< Current number of trees ('m_pFirst' and all it's siblings) */
        uint32   m_nMaxNumOfMarks;  /**< Maximum number of marks */
        Tree   **m_ppMark;          /**< Mark array, can be a null pointer (has 'm_nMaxNumOfMarks' elements) */


    //[-------------------------------------------------------]
    //[ Public virtual Iterable functions                     ]
    //[-------------------------------------------------------]
    public:
        virtual Iterator<ValueType> GetIterator(uint32 nIndex = 0) const override;
        virtual ConstIterator<ValueType> GetConstIterator(uint32 nIndex = 0) const override;
        virtual Iterator<ValueType> GetEndIterator() const override;
        virtual ConstIterator<ValueType> GetConstEndIterator() const override;


    //[-------------------------------------------------------]
    //[ Public virtual Heap functions                         ]
    //[-------------------------------------------------------]
    public:
        virtual void Clear() override;
        virtual bool IsEmpty() const override;
        virtual uint32 GetNumOfElements() const override;
        virtual bool Add(const KeyType &Key, const ValueType &Value) override;
        virtual bool GetTop(ValueType *pValue = nullptr, KeyType *pKey = nullptr) const override;
        virtual bool ExtractTop(ValueType *pValue = nullptr, KeyType *pKey = nullptr) override;


    //[-------------------------------------------------------]
    //[ Private virtual Heap functions                        ]
    //[-------------------------------------------------------]
    private:
        virtual Heap<KeyType, ValueType> &operator =(const Heap<KeyType, ValueType> &cHeap) override;


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLCore


//[-------------------------------------------------------]
//[ Implementation                                        ]
//[-------------------------------------------------------]
#include "PLCore/Container/FibonacciHeap.inl"


#endif // __PLCORE_CONTAINER_FIBONACCIHEAP_H__