priorityQueue.h

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 *   This file is part of the aGrUM/pyAgrum library.                        *
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 *       - Christophe GONZALES(_at_AMU)                                     *
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 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
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#ifndef GUM_PRIORITY_QUEUE_H
#define GUM_PRIORITY_QUEUE_H
 
#include <functional>
#include <sstream>
#include <string>
#include <utility>
#include <vector>
 
#include <agrum/agrum.h>
 
#include <agrum/base/core/hashTable.h>
 
#include <initializer_list>
#include <type_traits>
 
namespace gum {
 
#define GUM_PRIORITY_QUEUE_DEFAULT_CAPACITY 10
 
  // templates provided by this file
  template < typename Val, typename Priority, typename Cmp >
  class PriorityQueue;
  template < typename Val, typename Priority, typename Cmp >
  std::ostream& operator<<(std::ostream&, const PriorityQueue< Val, Priority, Cmp >&);
 
  // ===========================================================================
  // ===              GENERAL IMPLEMENTATION OF PRIORITY QUEUES              ===
  // ===========================================================================

  template < typename Val, typename Priority, typename Cmp, bool Gen >
  class PriorityQueueImplementation {
    friend class PriorityQueue< Val, Priority, Cmp >;
 
    public:
    using value_type      = Val;
    using reference       = Val&;
    using const_reference = const Val&;
    using pointer         = Val*;
    using const_pointer   = const Val*;
    using difference_type = std::ptrdiff_t;
 
    private:
    // ============================================================================
    // ============================================================================

    explicit PriorityQueueImplementation(Cmp compare, Size capacity);

    explicit PriorityQueueImplementation(std::initializer_list< std::pair< Val, Priority > > list);

    PriorityQueueImplementation(const PriorityQueueImplementation< Val, Priority, Cmp, Gen >& from);

    PriorityQueueImplementation(PriorityQueueImplementation< Val, Priority, Cmp, Gen >&& from);

    ~PriorityQueueImplementation();

 
    public:
    // ============================================================================
    // ============================================================================

    PriorityQueueImplementation< Val, Priority, Cmp, Gen >&
        operator=(const PriorityQueueImplementation< Val, Priority, Cmp, Gen >& from);

    PriorityQueueImplementation< Val, Priority, Cmp, Gen >&
        operator=(PriorityQueueImplementation< Val, Priority, Cmp, Gen >&& from);

    const Val& operator[](Size index_elt) const;

    // ============================================================================
    // ============================================================================

    Size size() const noexcept;

    bool empty() const noexcept;

    bool contains(const Val& val) const;


    const Val& top() const;

    const Priority& topPriority() const;

    Val pop();

    Size insert(const Val& val, const Priority& priority);

    Size insert(Val&& val, Priority&& priority);

    template < typename... Args >
    Size emplace(Args&&... args);

    void eraseTop();

    void eraseByPos(Size index);

    void erase(const Val& val);

    Size setPriorityByPos(Size index, const Priority& new_priority);

    Size setPriorityByPos(Size index, Priority&& new_priority);

    void setPriority(const Val& elt, const Priority& new_priority);

    void setPriority(const Val& elt, Priority&& new_priority);

    const Priority& priority(const Val& elt) const;

    const Priority& priorityByPos(Size index) const;

    void clear();

    const HashTable< Val, Size >& allValues() const noexcept;

    std::string toString() const;

    // ============================================================================
    // ============================================================================

    Size capacity() const noexcept;

    void resize(Size new_size);

 
    private:
    std::vector< std::pair< Priority, const Val* > > _heap_;

    HashTable< Val, Size > _indices_{HashTableConst::default_size, true, true};

    Size _nb_elements_{0};

    Cmp _cmp_;
  };
 
#ifndef DOXYGEN_SHOULD_SKIP_THIS
 
  // ===========================================================================
  // ===              SCALAR IMPLEMENTATION OF PRIORITY QUEUES               ===
  // ===========================================================================

  template < typename Val, typename Priority, typename Cmp >
  class PriorityQueueImplementation< Val, Priority, Cmp, true > {
    friend class PriorityQueue< Val, Priority, Cmp >;
 
    public:
    using value_type      = Val;
    using reference       = Val&;
    using const_reference = const Val&;
    using pointer         = Val*;
    using const_pointer   = const Val*;
    using difference_type = std::ptrdiff_t;
 
    private:
    // ============================================================================
    // ============================================================================

    explicit PriorityQueueImplementation(Cmp compare, Size capacity);

    explicit PriorityQueueImplementation(std::initializer_list< std::pair< Val, Priority > > list);

    PriorityQueueImplementation(
        const PriorityQueueImplementation< Val, Priority, Cmp, true >& from);

    PriorityQueueImplementation(PriorityQueueImplementation< Val, Priority, Cmp, true >&& from);

    ~PriorityQueueImplementation();

 
    public:
    // ============================================================================
    // ============================================================================

    PriorityQueueImplementation< Val, Priority, Cmp, true >&
        operator=(const PriorityQueueImplementation< Val, Priority, Cmp, true >& from);

    PriorityQueueImplementation< Val, Priority, Cmp, true >&
        operator=(PriorityQueueImplementation< Val, Priority, Cmp, true >&& from);

    const Val& operator[](Size index_elt) const;

    // ============================================================================
    // ============================================================================

    Size size() const noexcept;

    bool empty() const noexcept;

    bool contains(Val val) const;


    const Val& top() const;

    const Priority& topPriority() const;

    Val pop();

    Size insert(Val val, const Priority& priority);

    Size insert(Val val, Priority&& priority);

    template < typename... Args >
    Size emplace(Args&&... args);

    void eraseTop();

    void eraseByPos(Size index);

    void erase(Val val);

    Size setPriorityByPos(Size index, const Priority& new_priority);

    Size setPriorityByPos(Size index, Priority&& new_priority);

    void setPriority(Val elt, const Priority& new_priority);

    void setPriority(Val elt, Priority&& new_priority);

    const Priority& priority(Val elt) const;

    const Priority& priorityByPos(Size index) const;

    void clear();

    const HashTable< Val, Size >& allValues() const noexcept;

    std::string toString() const;

    // ============================================================================
    // ============================================================================

    Size capacity() const noexcept;

    void resize(Size new_size);

 
    private:
    std::vector< std::pair< Priority, Val > > _heap_;

    HashTable< Val, Size > _indices_{HashTableConst::default_size, true, true};

    Size _nb_elements_{0};

    Cmp _cmp_;
  };
 
#endif /* DOXYGEN_SHOULD_SKIP_THIS */
 
  // ===========================================================================
  // ===                           PRIORITY QUEUES                           ===
  // ===========================================================================
  template < typename Val, typename Priority = int, typename Cmp = std::less< Priority > >
  class PriorityQueue:
      public PriorityQueueImplementation< Val, Priority, Cmp, std::is_scalar< Val >::value > {
    public:
    using value_type      = Val;
    using reference       = Val&;
    using const_reference = const Val&;
    using pointer         = Val*;
    using const_pointer   = const Val*;
    using difference_type = std::ptrdiff_t;
 
    using Implementation
        = PriorityQueueImplementation< Val, Priority, Cmp, std::is_scalar< Val >::value >;
 
    // ============================================================================
    // ============================================================================

    explicit PriorityQueue(Cmp  compare  = Cmp(),
                           Size capacity = GUM_PRIORITY_QUEUE_DEFAULT_CAPACITY);

    explicit PriorityQueue(std::initializer_list< std::pair< Val, Priority > > list);

    PriorityQueue(const PriorityQueue< Val, Priority, Cmp >& from);

    PriorityQueue(PriorityQueue< Val, Priority, Cmp >&& from);

    ~PriorityQueue();

    // ============================================================================
    // ============================================================================

    PriorityQueue< Val, Priority, Cmp >& operator=(const PriorityQueue< Val, Priority, Cmp >& from);

    PriorityQueue< Val, Priority, Cmp >& operator=(PriorityQueue< Val, Priority, Cmp >&& from);

  };
 
} /* namespace gum */
 
#ifndef GUM_NO_EXTERN_TEMPLATE_CLASS
extern template class gum::PriorityQueue< std::string >;
extern template class gum::PriorityQueue< int, int >;
#endif
 
// always include the implementation of the templates
#include <agrum/base/core/priorityQueue_tpl.h>
 
#endif /* GUM_PRIORITY_QUEUE_H */