A MultiPriorityQueue is a heap in which each element has a mutable priority and duplicates are allowed. More...

#include <agrum/base/core/multiPriorityQueue.h>

Collaboration diagram for gum::MultiPriorityQueue< Val, Priority, Cmp >:

Public Types

using	value_type = Val
	types for STL compliance
using	reference = Val&
	types for STL compliance
using	const_reference = const Val&
	types for STL compliance
using	pointer = Val*
	types for STL compliance
using	const_pointer = const Val*
	types for STL compliance
using	difference_type = std::ptrdiff_t
	types for STL compliance

Public Member Functions
Constructors / Destructors
	MultiPriorityQueue (Cmp compare=Cmp(), Size capacity=GUM_MULTIPLE_PRIORITY_QUEUE_DEFAULT_CAPACITY)
	Basic constructor.
	MultiPriorityQueue (std::initializer_list< std::pair< Val, Priority > > list)
	Initializer list constructor.
	MultiPriorityQueue (const MultiPriorityQueue< Val, Priority, Cmp > &from)
	Copy constructor.
	MultiPriorityQueue (MultiPriorityQueue< Val, Priority, Cmp > &&from)
	Move constructor.
	~MultiPriorityQueue ()
	Class destructor.
Operators
MultiPriorityQueue< Val, Priority, Cmp > &	operator= (const MultiPriorityQueue< Val, Priority, Cmp > &from)
	Copy operator.
MultiPriorityQueue< Val, Priority, Cmp > &	operator= (MultiPriorityQueue< Val, Priority, Cmp > &&from)
	Move operator.
const Val &	operator[] (Size index_elt) const
	Returns the element at index "index_elt" from the priority queue.
Accessors / Modifiers
Size	size () const noexcept
	Returns the number of elements in the priority queue.
bool	empty () const noexcept
	Indicates whether the priority queue is empty.
bool	contains (const Val &val) const
	Indicates whether the priority queue contains a given value.
const Val &	top () const
	Returns the element at the top of the priority queue.
const Priority &	topPriority () const
	Returns the priority of the top element.
Val	pop ()
	Removes the top element from the priority queue and return it.
Size	insert (const Val &val, const Priority &priority)
	Inserts a new (a copy) element in the priority queue.
Size	insert (Val &&val, Priority &&priority)
	Inserts (by move) a new element in the priority queue.
template<typename... Args>
Size	emplace (Args &&... args)
	Emplace a new element into the priority queue.
void	eraseTop ()
	Removes the top of the priority queue (but does not return it).
void	eraseByPos (Size index)
	Removes the element at position "index" from the priority queue.
void	erase (const Val &val)
	Removes a given element from the priority queue (but does not return it).
Size	setPriorityByPos (Size index, const Priority &new_priority)
	Modifies the priority of the element at position "index" of the queue.
Size	setPriorityByPos (Size index, Priority &&new_priority)
	Modifies the priority of the element at position "index" of the queue.
void	setPriority (const Val &elt, const Priority &new_priority)
	Modifies the priority of each instance of a given element.
const Priority &	priority (const Val &elt) const
	Returns the priority of an instance of the value passed in argument.
void	clear ()
	Removes all the elements from the queue.
const HashTable< Val, std::vector< Size > > &	allValues () const
	Returns a gum::HashTable the keys of which are the values stored in the queue.
std::string	toString () const
	Displays the content of the queue.
Fine tuning
Size	capacity () const noexcept
	Return the size of the internal structure storing the priority queue.
void	resize (Size new_size)
	Changes the size of the internal structure storing the priority queue.

Private Attributes
std::vector< std::pair< Priority, const Val * > >	_heap_
	An array storing all the elements of the heap as well as their score.
HashTable< Val, std::vector< Size > >	_indices_
	A hashtable for quickly finding the elements by their value.
Size	_nb_elements_ {0}
	The number of elements in the heap.
Cmp	_cmp_
	Comparison function.

Detailed Description

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>
class gum::MultiPriorityQueue< Val, Priority, Cmp >

A MultiPriorityQueue is a heap in which each element has a mutable priority and duplicates are allowed.

A priority queue is quite similar to a heap except that a priority (a score) is assigned to each element in the structure. The elements are sorted according to a weak order on the scores. The priority of any element can be changed at any moment by the user. The priority queue then restores a heap property accordingly.

Usage example:: // create a priority queue of strings, the priorities of which are

// integers the element at the top of the queue has the smallest priority

MultiPriorityQueue<std::string> queue1;

// insert elements into the queue

queue1.insert (8, "AAA");

queue1.insert (10, "BBB");

queue1.insert (2, "CCC");

queue1.insert (23, "DDD");

queue1.insert (24, "EEE");

queue1.insert (10, "AAA");

// copy the queue

MultiPriorityQueue<std::string> queue2 = queue1;

// initializer list constructor

MultiPriorityQueue<std::string,int>

queue3 { std::pair<std::string,int> ( "aa", 3 ),

std::pair<std::string,int> ( "bb", 2 ) };

// create a priority queue of strings, the priorities of which are

// pairs of ints

MultiPriorityQueue< std::string, std::pair<int,int> > queue3;

// get the top element, then remove it

std::cerr << queue2.top() << std::endl;

queue2.eraseTop();

// get the top element, then remove it

std::cerr << queue2.pop() << std::endl;

// output the content of the queue

std::cerr << queue1 << std::endl;

// change the priority of the element at position 3

Size new_pos=queue1.setPriorityByPos (3,100);

// change the priority of all instances of element "AAA"

queue1.setPriority ("AAA",100);

gum::MultiPriorityQueue
A MultiPriorityQueue is a heap in which each element has a mutable priority and duplicates are allowe...
Definition multiPriorityQueue.h:143

gum::MultiPriorityQueue::insert
Size insert(const Val &val, const Priority &priority)
Inserts a new (a copy) element in the priority queue.
Definition multiPriorityQueue_tpl.h:305

gum::MultiPriorityQueue::top
const Val & top() const
Returns the element at the top of the priority queue.
Definition multiPriorityQueue_tpl.h:172

gum::MultiPriorityQueue::pop
Val pop()
Removes the top element from the priority queue and return it.
Definition multiPriorityQueue_tpl.h:287

gum::MultiPriorityQueue::setPriority
void setPriority(const Val &elt, const Priority &new_priority)
Modifies the priority of each instance of a given element.
Definition multiPriorityQueue_tpl.h:586

gum::MultiPriorityQueue::eraseTop
void eraseTop()
Removes the top of the priority queue (but does not return it).
Definition multiPriorityQueue_tpl.h:281

gum::MultiPriorityQueue::setPriorityByPos
Size setPriorityByPos(Size index, const Priority &new_priority)
Modifies the priority of the element at position "index" of the queue.
Definition multiPriorityQueue_tpl.h:464

gum::MultiPriorityQueue::MultiPriorityQueue
MultiPriorityQueue(Cmp compare=Cmp(), Size capacity=GUM_MULTIPLE_PRIORITY_QUEUE_DEFAULT_CAPACITY)
Basic constructor.
Definition multiPriorityQueue_tpl.h:58

gum::Size
std::size_t Size
In aGrUM, hashed values are unsigned long int.
Definition types.h:74

Template Parameters

Val	The values type stored in the gum::MultiPriorityQueue.
Priority	The priorities type.
Cmp	The priorities comparator.

Definition at line 143 of file multiPriorityQueue.h.

Member Typedef Documentation

◆ const_pointer

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

using gum::MultiPriorityQueue< Val, Priority, Cmp >::const_pointer = const Val*

types for STL compliance

Definition at line 151 of file multiPriorityQueue.h.

◆ const_reference

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

using gum::MultiPriorityQueue< Val, Priority, Cmp >::const_reference = const Val&

types for STL compliance

Definition at line 149 of file multiPriorityQueue.h.

◆ difference_type

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

using gum::MultiPriorityQueue< Val, Priority, Cmp >::difference_type = std::ptrdiff_t

types for STL compliance

Definition at line 152 of file multiPriorityQueue.h.

◆ pointer

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

using gum::MultiPriorityQueue< Val, Priority, Cmp >::pointer = Val*

types for STL compliance

Definition at line 150 of file multiPriorityQueue.h.

◆ reference

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

using gum::MultiPriorityQueue< Val, Priority, Cmp >::reference = Val&

types for STL compliance

Definition at line 148 of file multiPriorityQueue.h.

◆ value_type

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

using gum::MultiPriorityQueue< Val, Priority, Cmp >::value_type = Val

types for STL compliance

Definition at line 147 of file multiPriorityQueue.h.

Constructor & Destructor Documentation

◆ MultiPriorityQueue() [1/4]

template<typename Val, typename Priority, typename Cmp>

gum::MultiPriorityQueue< Val, Priority, Cmp >::MultiPriorityQueue	(	Cmp	compare = Cmp(),
		Size	capacity = GUM_MULTIPLE_PRIORITY_QUEUE_DEFAULT_CAPACITY )

explicit

Basic constructor.

Creates an empty priority queue.

Parameters

compare	a function taking two elements in argument, say e1 and e2, and returning a Boolean indicating wether e1 < e2, i.e., whether e1 should be nearer than e2 to the top of the heap.
capacity	the size of the internal data structures containing the elements (could be for instance vectors or hashtables).

Definition at line 58 of file multiPriorityQueue_tpl.h.

                                                                                         :
      _indices_(capacity >> 1, true, false), _cmp_(compare) {
    _heap_.reserve(capacity);
 
    // for debugging purposes
    GUM_CONSTRUCTOR(MultiPriorityQueue);
  }

References MultiPriorityQueue(), _cmp_, _heap_, _indices_, and capacity().

Referenced by MultiPriorityQueue(), MultiPriorityQueue(), MultiPriorityQueue(), MultiPriorityQueue(), ~MultiPriorityQueue(), operator=(), and operator=().

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◆ MultiPriorityQueue() [2/4]

template<typename Val, typename Priority, typename Cmp>

gum::MultiPriorityQueue< Val, Priority, Cmp >::MultiPriorityQueue ( std::initializer_list< std::pair< Val, Priority > > list )

explicit

Initializer list constructor.

The elements of the initializer list are pairs <Val,Priority>. The comparison function is the default one, i.e., std::less<Priority>.

Parameters

list	The initializer list.

Definition at line 68 of file multiPriorityQueue_tpl.h.

                                                            :
      _indices_(Size(list.size()) / 2, true, false) {
    // fill the queue
    _heap_.reserve(list.size());
    for (const auto& elt: list) {
      insert(elt.first, elt.second);
    }
 
    // for debugging purposes
    GUM_CONSTRUCTOR(MultiPriorityQueue);
  }

References MultiPriorityQueue(), _heap_, _indices_, insert(), and size().

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◆ MultiPriorityQueue() [3/4]

template<typename Val, typename Priority, typename Cmp>

gum::MultiPriorityQueue< Val, Priority, Cmp >::MultiPriorityQueue ( const MultiPriorityQueue< Val, Priority, Cmp > & from )

Copy constructor.

Parameters

from	The gum::MultiPriorityQueue to copy.

Definition at line 83 of file multiPriorityQueue_tpl.h.

                                                            :
      _heap_(from._heap_), _indices_(from._indices_), _nb_elements_(from._nb_elements_),
      _cmp_(from._cmp_) {
    // for debugging purposes
    GUM_CONS_CPY(MultiPriorityQueue);
 
    // fill the heap structure
    for (const auto& val_and_index: _indices_) {
      const Val*                 val  = &(val_and_index.first);
      const std::vector< Size >& vect = val_and_index.second;
      for (auto index: vect) {
        _heap_[index].second = val;
      }
    }
  }

References MultiPriorityQueue(), _cmp_, _heap_, _indices_, and _nb_elements_.

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◆ MultiPriorityQueue() [4/4]

template<typename Val, typename Priority, typename Cmp>

gum::MultiPriorityQueue< Val, Priority, Cmp >::MultiPriorityQueue ( MultiPriorityQueue< Val, Priority, Cmp > && from )

Move constructor.

Parameters

from	The gum::MultiPriorityQueue to move.

Definition at line 102 of file multiPriorityQueue_tpl.h.

                                                       :
      _heap_(std::move(from._heap_)), _indices_(std::move(from._indices_)),
      _nb_elements_(std::move(from._nb_elements_)), _cmp_(std::move(from._cmp_)) {
    // for debugging purposes
    GUM_CONS_MOV(MultiPriorityQueue);
  }

References MultiPriorityQueue(), _cmp_, _heap_, _indices_, and _nb_elements_.

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◆ ~MultiPriorityQueue()

template<typename Val, typename Priority, typename Cmp>

gum::MultiPriorityQueue< Val, Priority, Cmp >::~MultiPriorityQueue ( )

Class destructor.

Definition at line 112 of file multiPriorityQueue_tpl.h.

                                                                {
    // for debugging purposes
    GUM_DESTRUCTOR(MultiPriorityQueue);
  }

References MultiPriorityQueue().

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Member Function Documentation

◆ allValues()

template<typename Val, typename Priority, typename Cmp>

const HashTable< Val, std::vector< Size > > & gum::MultiPriorityQueue< Val, Priority, Cmp >::allValues ( ) const

Returns a gum::HashTable the keys of which are the values stored in the queue.

The keys of the gum::HashTable correspond to the values stored in the priority queue and, for each key, the corresponding value is the list of indices in the queue where we can find the key.

Returns: Returns a gum::HashTable the keys of which are the values stored in the queue.

Definition at line 299 of file multiPriorityQueue_tpl.h.

                                                                {
    return reinterpret_cast< const HashTable< Val, std::vector< Size > >& >(_indices_);
  }

References _indices_.

◆ capacity()

template<typename Val, typename Priority, typename Cmp>

Size gum::MultiPriorityQueue< Val, Priority, Cmp >::capacity ( ) const

noexcept

Return the size of the internal structure storing the priority queue.

Returns: Return the size of the internal structure storing the priority queue.

Definition at line 194 of file multiPriorityQueue_tpl.h.

                                                                         {
    return Size(_heap_.capacity());
  }

References _heap_.

Referenced by MultiPriorityQueue().

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◆ clear()

template<typename Val, typename Priority, typename Cmp>

void gum::MultiPriorityQueue< Val, Priority, Cmp >::clear ( )

Removes all the elements from the queue.

Definition at line 209 of file multiPriorityQueue_tpl.h.

                                                       {
    _nb_elements_ = 0;
    _heap_.clear();
    _indices_.clear();
  }

References _heap_, _indices_, and _nb_elements_.

◆ contains()

template<typename Val, typename Priority, typename Cmp>

bool gum::MultiPriorityQueue< Val, Priority, Cmp >::contains ( const Val & val ) const

Indicates whether the priority queue contains a given value.

Parameters

val	The value to check if it is in the priority queue.

Returns: Returns true if the priority queue cotains the given value.

Definition at line 430 of file multiPriorityQueue_tpl.h.

                                                                              {
    return _indices_.exists(val);
  }

References _indices_.

◆ emplace()

template<typename Val, typename Priority, typename Cmp>

template<typename... Args>

Size gum::MultiPriorityQueue< Val, Priority, Cmp >::emplace ( Args &&... args )

Emplace a new element into the priority queue.

See method gum::MultiPriorityQueue::eraseByPos(Size) for more details about the index.

Template Parameters

Args	The emplace arguments types.

Parameters

args	The emplace arguments.

Returns: the index of the element inserted into the priority queue.

Definition at line 416 of file multiPriorityQueue_tpl.h.

                                                                       {
    std::pair< Val, Priority > new_elt
        = std::make_pair< Val, Priority >(std::forward< Args >(args)...);
    return insert(std::move(new_elt.first), std::move(new_elt.second));
  }

References insert().

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◆ empty()

template<typename Val, typename Priority, typename Cmp>

bool gum::MultiPriorityQueue< Val, Priority, Cmp >::empty ( ) const

noexcept

Indicates whether the priority queue is empty.

Returns: Indicates whether the priority queue is empty.

Definition at line 424 of file multiPriorityQueue_tpl.h.

                                                                      {
    return (_nb_elements_ == 0);
  }

References _nb_elements_.

◆ erase()

template<typename Val, typename Priority, typename Cmp>

void gum::MultiPriorityQueue< Val, Priority, Cmp >::erase ( const Val & val )

Removes a given element from the priority queue (but does not return it).

If the element cannot be found, the function returns without throwing any exception.

If the queue contains several times this element, then the one with the smallest index is removed.

Parameters

val	the element we wish to remove.

Definition at line 275 of file multiPriorityQueue_tpl.h.

                                                                     {
    if (auto p = _indices_.tryGet(val)) eraseByPos((*p)[0]);
  }

References _indices_, and eraseByPos().

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◆ eraseByPos()

template<typename Val, typename Priority, typename Cmp>

void gum::MultiPriorityQueue< Val, Priority, Cmp >::eraseByPos ( Size index )

Removes the element at position "index" from the priority queue.

If the element cannot be found, the function returns without throwing any exception.

The priority is computed as follows: suppose that the queue is a complete binary tree where all levels are completely filled except, eventually, the last one. In this case, the elements of the last level are all on the left of the tree.

We assign 0 to the root, then parsing the tree from top to bottom then from left to right we increment the index and assigned it to the current node. Doing so, we get a unique index for each element. This is precisely what the index passed in argument of the function represents.

Parameters

index represents the position of the element to be removed.

Definition at line 217 of file multiPriorityQueue_tpl.h.

                                                                      {
    if (index >= _nb_elements_) return;
 
    // remove the element from the hashtable
    const Val&           del_val    = *(_heap_[index].second);
    std::vector< Size >& vect_index = _indices_[del_val];
    if (vect_index.size() == 1) _indices_.erase(del_val);
    else {
      for (auto& v_index: vect_index) {
        if (v_index == index) {
          v_index = vect_index.back();
          vect_index.pop_back();
          break;
        }
      }
    }
 
    // put the last element at the "index" location
    std::pair< Priority, const Val* > last = std::move(_heap_.back());
    _heap_.pop_back();
    --_nb_elements_;
 
    if (!_nb_elements_ || (index == _nb_elements_)) return;
 
    // restore the heap property
    Size i = index;
 
    for (Size j = (index << 1) + 1; j < _nb_elements_; i = j, j = (j << 1) + 1) {
      // let j be the max child
      if ((j + 1 < _nb_elements_) && _cmp_(_heap_[j + 1].first, _heap_[j].first)) ++j;
 
      // if "last" is lower than heap[j], "last" must be stored at index i
      if (_cmp_(last.first, _heap_[j].first)) break;
 
      // else pull up the jth node
      _heap_[i]                       = std::move(_heap_[j]);
      std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
      for (auto& v_index: vect_index) {
        if (v_index == j) {
          v_index = i;
          break;
        }
      }
    }
 
    // put "last" back into the heap
    _heap_[i]                         = std::move(last);
    std::vector< Size >& last_indices = _indices_[*(_heap_[i].second)];
    for (auto& v_index: last_indices) {
      if (v_index == _nb_elements_) {
        v_index = i;
        break;
      }
    }
  }

References _heap_, _indices_, and _nb_elements_.

Referenced by erase(), and eraseTop().

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◆ eraseTop()

template<typename Val, typename Priority, typename Cmp>

void gum::MultiPriorityQueue< Val, Priority, Cmp >::eraseTop ( )

Removes the top of the priority queue (but does not return it).

If the heap is empty, it does nothing (in particular, it does not throw any exception).

Definition at line 281 of file multiPriorityQueue_tpl.h.

                                                          {
    eraseByPos(0);
  }

References eraseByPos().

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◆ insert() [1/2]

template<typename Val, typename Priority, typename Cmp>

Size gum::MultiPriorityQueue< Val, Priority, Cmp >::insert	(	const Val &	val,
		const Priority &	priority )

Inserts a new (a copy) element in the priority queue.

See method gum::MultiPriorityQueue::eraseByPos(Size) for more details about the index.

Parameters

val	The value to insert.
priority	The value priority.

Returns: Returns the index of the element inserted into the priority queue.

Definition at line 305 of file multiPriorityQueue_tpl.h.

                                                                                                {
    // create the entry in the indices hashtable
    const Val*           new_val;
    std::vector< Size >* new_vect;
    if (auto existing = _indices_.tryGet(val); !existing) {
      auto& new_elt = _indices_.insert(val, std::vector< Size >());
      new_val       = &(new_elt.first);
      new_vect      = &(new_elt.second);
    } else {
      new_val  = &(_indices_.key(val));
      new_vect = &(*existing);
    }
 
    try {
      new_vect->push_back(0);
    } catch (...) {
      if (new_vect->empty()) { _indices_.erase(val); }
      throw;
    }
 
    try {
      _heap_.push_back(std::pair< Priority, const Val* >(priority, new_val));
    } catch (...) {
      if (new_vect->size() == 1) { _indices_.erase(val); }
      throw;
    }
 
    std::pair< Priority, const Val* > new_heap_val = std::move(_heap_[_nb_elements_]);
    ++_nb_elements_;
 
    // restore the heap property
    Size i = _nb_elements_ - 1;
 
    for (Size j = (i - 1) >> 1; i && _cmp_(new_heap_val.first, _heap_[j].first);
         i = j, j = (j - 1) >> 1) {
      _heap_[i]                       = std::move(_heap_[j]);
      std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
      for (auto& index: vect_index) {
        if (index == j) {
          index = i;
          break;
        }
      }
    }
 
    // put the new bucket into the heap
    _heap_[i].first  = std::move(new_heap_val.first);
    _heap_[i].second = new_val;
    new_vect->back() = i;
 
    return i;
  }

References _indices_, and priority().

Referenced by MultiPriorityQueue(), and emplace().

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◆ insert() [2/2]

template<typename Val, typename Priority, typename Cmp>

Size gum::MultiPriorityQueue< Val, Priority, Cmp >::insert	(	Val &&	val,
		Priority &&	priority )

Inserts (by move) a new element in the priority queue.

See method gum::MultiPriorityQueue::eraseByPos(Size) for more details about the index.

Parameters

val	The value to insert.
priority	The value priority.

Returns: Returns the index of the element inserted into the priority queue.

Definition at line 360 of file multiPriorityQueue_tpl.h.

                                                                                      {
    // create the entry in the indices hashtable
    const Val*           new_val;
    std::vector< Size >* new_vect;
    if (auto existing = _indices_.tryGet(val); !existing) {
      auto& new_elt = _indices_.insert(std::move(val), std::vector< Size >());
      new_val       = &(new_elt.first);
      new_vect      = &(new_elt.second);
    } else {
      new_val  = &(_indices_.key(val));
      new_vect = &(*existing);
    }
 
    try {
      new_vect->push_back(0);
    } catch (...) {
      if (new_vect->empty()) { _indices_.erase(*new_val); }
      throw;
    }
 
    try {
      _heap_.push_back(std::pair< Priority, const Val* >(std::move(priority), new_val));
    } catch (...) {
      if (new_vect->size() == 1) { _indices_.erase(*new_val); }
      throw;
    }
 
    std::pair< Priority, const Val* > new_heap_val = std::move(_heap_[_nb_elements_]);
    ++_nb_elements_;
 
    // restore the heap property
    Size i = _nb_elements_ - 1;
 
    for (Size j = (i - 1) >> 1; i && _cmp_(new_heap_val.first, _heap_[j].first);
         i = j, j = (j - 1) >> 1) {
      _heap_[i]                       = std::move(_heap_[j]);
      std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
      for (auto& index: vect_index) {
        if (index == j) {
          index = i;
          break;
        }
      }
    }
 
    // put the new bucket into the heap
    _heap_[i].first  = std::move(new_heap_val.first);
    _heap_[i].second = new_val;
    new_vect->back() = i;
 
    return i;
  }

References _indices_, and priority().

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◆ operator=() [1/2]

template<typename Val, typename Priority, typename Cmp>

MultiPriorityQueue< Val, Priority, Cmp > & gum::MultiPriorityQueue< Val, Priority, Cmp >::operator= ( const MultiPriorityQueue< Val, Priority, Cmp > & from )

Copy operator.

When a problem occurs during the copy (for instance when not enough memory is available), the operator guarantees that the heap stays in a coherent state. Actually, the priority queue becomes empty. An exception is then thrown.

Parameters

from	The gum::MultiPriorityQueue to copy.

Definition at line 119 of file multiPriorityQueue_tpl.h.

                                                            {
    // for debugging purposes
    GUM_OP_CPY(MultiPriorityQueue);
 
    try {
      // set the comprison function
      _cmp_ = from._cmp_;
 
      // copy the indices and the heap
      _indices_     = from._indices_;
      _heap_        = from._heap_;
      _nb_elements_ = from._nb_elements_;
 
      // restore the link between  _indices_ and  _heap_
      for (const auto& val_and_index: _indices_) {
        const Val*                 val  = &(val_and_index.first);
        const std::vector< Size >& vect = val_and_index.second;
        for (auto index: vect) {
          _heap_[index].second = val;
        }
      }
    } catch (...) {
      _heap_.clear();
      _indices_.clear();
      _nb_elements_ = 0;
 
      throw;
    }
 
    return *this;
  }

References MultiPriorityQueue(), _cmp_, _heap_, _indices_, and _nb_elements_.

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◆ operator=() [2/2]

template<typename Val, typename Priority, typename Cmp>

MultiPriorityQueue< Val, Priority, Cmp > & gum::MultiPriorityQueue< Val, Priority, Cmp >::operator= ( MultiPriorityQueue< Val, Priority, Cmp > && from )

Move operator.

Parameters

from	The gum::MultiPriorityQueue to copy.

Definition at line 154 of file multiPriorityQueue_tpl.h.

                                                       {
    // avoid self assignment
    if (this != &from) {
      // for debugging purposes
      GUM_OP_MOV(MultiPriorityQueue);
 
      _cmp_         = std::move(from._cmp_);
      _indices_     = std::move(from._indices_);
      _heap_        = std::move(from._heap_);
      _nb_elements_ = std::move(from._nb_elements_);
    }
 
    return *this;
  }

References MultiPriorityQueue(), _cmp_, _heap_, _indices_, and _nb_elements_.

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◆ operator[]()

template<typename Val, typename Priority, typename Cmp>

const Val & gum::MultiPriorityQueue< Val, Priority, Cmp >::operator[] ( Size index_elt ) const

Returns the element at index "index_elt" from the priority queue.

Parameters

index_elt The index of the element to return.

Returns: Returns the element at index "index_elt" from the priority queue.

Exceptions

NotFound Raised if the element does not exist.

Definition at line 436 of file multiPriorityQueue_tpl.h.

                                                                                  {
    if (index >= _nb_elements_) {
      GUM_ERROR(NotFound, "not enough elements in the MultiPriorityQueue")
    }
 
    return *(_heap_[index].second);
  }

References _nb_elements_, and GUM_ERROR.

◆ pop()

template<typename Val, typename Priority, typename Cmp>

Val gum::MultiPriorityQueue< Val, Priority, Cmp >::pop ( )

Removes the top element from the priority queue and return it.

Returns: Returns the top element from the priority queue.

Exceptions

NotFound Raised if the queue is empty.

Definition at line 287 of file multiPriorityQueue_tpl.h.

                                                    {
    if (!_nb_elements_) { GUM_ERROR(NotFound, "empty priority queue") }
 
    Val v = *(_heap_[0].second);
    eraseByPos(0);
 
    return v;
  }

References _heap_, _nb_elements_, and GUM_ERROR.

◆ priority()

template<typename Val, typename Priority, typename Cmp>

const Priority & gum::MultiPriorityQueue< Val, Priority, Cmp >::priority ( const Val & elt ) const

Returns the priority of an instance of the value passed in argument.

Of course, this method is really meaningful only when there is only one instance of the given element within the PriorityQueue.

Parameters

elt	The element for which the priority is returned.

Returns: Returns the priority of an instance of the value passed in argument.

Exceptions

NotFound Raised if the element cannot be found.

Definition at line 597 of file multiPriorityQueue_tpl.h.

                                                                                         {
    return _heap_[_indices_[elt][0]].first;
  }

References _heap_, and _indices_.

Referenced by insert(), and insert().

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◆ resize()

template<typename Val, typename Priority, typename Cmp>

void gum::MultiPriorityQueue< Val, Priority, Cmp >::resize ( Size new_size )

Changes the size of the internal structure storing the priority queue.

Parameters

new_size The internal structure new size.

Returns: Changes the size of the internal structure storing the priority queue.

Definition at line 200 of file multiPriorityQueue_tpl.h.

                                                                     {
    if (new_size < _nb_elements_) return;
 
    _heap_.reserve(new_size);
    _indices_.resize(new_size / 2);
  }

References _heap_, _indices_, and _nb_elements_.

◆ setPriority()

template<typename Val, typename Priority, typename Cmp>

void gum::MultiPriorityQueue< Val, Priority, Cmp >::setPriority	(	const Val &	elt,
		const Priority &	new_priority )

Modifies the priority of each instance of a given element.

Parameters

elt	The value to update.
new_priority	The values new priority.

Exceptions

NotFound Raised if the element cannot be found.

Definition at line 586 of file multiPriorityQueue_tpl.h.

                                                                                           {
    std::vector< Size >& vect_index = _indices_[elt];
 
    for (auto index: vect_index) {
      setPriorityByPos(index, new_priority);
    }
  }

References _indices_, and setPriorityByPos().

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◆ setPriorityByPos() [1/2]

template<typename Val, typename Priority, typename Cmp>

Size gum::MultiPriorityQueue< Val, Priority, Cmp >::setPriorityByPos	(	Size	index,
		const Priority &	new_priority )

Modifies the priority of the element at position "index" of the queue.

Parameters

index	The index of the element to update.
new_priority	The element's new priority.

Returns: Returns the elements new priority.

Exceptions

NotFound Raised if the element cannot be found.

Definition at line 464 of file multiPriorityQueue_tpl.h.

                                                                                                {
    // check whether the element the priority of which should be changed exists
    if (index >= _nb_elements_) {
      GUM_ERROR(NotFound, "not enough elements in the MultiPriorityQueue")
    }
 
    // get the element itself
    const Val* val = _heap_[index].second;
 
    // restore the heap property
    Size i = index;
 
    // move val upward if needed
    for (Size j = (i - 1) >> 1; i && _cmp_(new_priority, _heap_[j].first);
         i = j, j = (j - 1) >> 1) {
      _heap_[i]                       = std::move(_heap_[j]);
      std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
      for (auto& idx: vect_index) {
        if (idx == j) {
          idx = i;
          break;
        }
      }
    }
 
    // move val downward if needed
    for (Size j = (i << 1) + 1; j < _nb_elements_; i = j, j = (j << 1) + 1) {
      // let j be the max child
      if ((j + 1 < _nb_elements_) && _cmp_(_heap_[j + 1].first, _heap_[j].first)) ++j;
 
      // if "val" is lower than heap[j], "val" must be stored at index i
      if (_cmp_(new_priority, _heap_[j].first)) break;
 
      // else pull up the jth node
      _heap_[i]                       = std::move(_heap_[j]);
      std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
      for (auto& idx: vect_index) {
        if (idx == j) {
          idx = i;
          break;
        }
      }
    }
 
    // update the index of val
    _heap_[i].first                 = new_priority;
    _heap_[i].second                = val;
    std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
    for (auto& idx: vect_index) {
      if (idx == index) {
        idx = i;
        break;
      }
    }
 
    return i;
  }

References _cmp_, _heap_, _indices_, _nb_elements_, and GUM_ERROR.

Referenced by setPriority().

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◆ setPriorityByPos() [2/2]

template<typename Val, typename Priority, typename Cmp>

Size gum::MultiPriorityQueue< Val, Priority, Cmp >::setPriorityByPos	(	Size	index,
		Priority &&	new_priority )

Modifies the priority of the element at position "index" of the queue.

Parameters

index	The index of the element to update.
new_priority	The element's new priority.

Returns: Returns the elements new priority.

Exceptions

NotFound Raised if the element cannot be found.

Definition at line 525 of file multiPriorityQueue_tpl.h.

                                                                                           {
    // check whether the element the priority of which should be changed exists
    if (index >= _nb_elements_) {
      GUM_ERROR(NotFound, "not enough elements in the MultiPriorityQueue")
    }
 
    // get the element itself
    const Val* val = _heap_[index].second;
 
    // restore the heap property
    Size i = index;
 
    // move val upward if needed
    for (Size j = (i - 1) >> 1; i && _cmp_(new_priority, _heap_[j].first);
         i = j, j = (j - 1) >> 1) {
      _heap_[i]                       = std::move(_heap_[j]);
      std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
      for (auto& idx: vect_index) {
        if (idx == j) {
          idx = i;
          break;
        }
      }
    }
 
    // move val downward if needed
    for (Size j = (i << 1) + 1; j < _nb_elements_; i = j, j = (j << 1) + 1) {
      // let j be the max child
      if ((j + 1 < _nb_elements_) && _cmp_(_heap_[j + 1].first, _heap_[j].first)) ++j;
 
      // if "val" is lower than heap[j], "val" must be stored at index i
      if (_cmp_(new_priority, _heap_[j].first)) break;
 
      // else pull up the jth node
      _heap_[i]                       = std::move(_heap_[j]);
      std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
      for (auto& idx: vect_index) {
        if (idx == j) {
          idx = i;
          break;
        }
      }
    }
 
    // update the index of val
    _heap_[i].first                 = std::move(new_priority);
    _heap_[i].second                = val;
    std::vector< Size >& vect_index = _indices_[*(_heap_[i].second)];
    for (auto& idx: vect_index) {
      if (idx == index) {
        idx = i;
        break;
      }
    }
 
    return i;
  }

References _cmp_, _heap_, _indices_, _nb_elements_, and GUM_ERROR.

◆ size()

template<typename Val, typename Priority, typename Cmp>

Size gum::MultiPriorityQueue< Val, Priority, Cmp >::size ( ) const

noexcept

Returns the number of elements in the priority queue.

Returns: Returns the number of elements in the priority queue.

Definition at line 188 of file multiPriorityQueue_tpl.h.

                                                                     {
    return _nb_elements_;
  }

References _nb_elements_.

Referenced by MultiPriorityQueue().

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◆ top()

template<typename Val, typename Priority, typename Cmp>

const Val & gum::MultiPriorityQueue< Val, Priority, Cmp >::top ( ) const

Returns the element at the top of the priority queue.

Returns: Returns the element at the top of the priority queue.

Exceptions

NotFound Raised if the queue is empty.

Definition at line 172 of file multiPriorityQueue_tpl.h.

                                                                 {
    if (!_nb_elements_) { GUM_ERROR(NotFound, "empty priority queue") }
 
    return *(_heap_[0].second);
  }

References _heap_, _nb_elements_, and GUM_ERROR.

◆ topPriority()

template<typename Val, typename Priority, typename Cmp>

const Priority & gum::MultiPriorityQueue< Val, Priority, Cmp >::topPriority ( ) const

Returns the priority of the top element.

Exceptions

NotFound Raised if the queue is empty.

Definition at line 180 of file multiPriorityQueue_tpl.h.

                                                                              {
    if (!_nb_elements_) { GUM_ERROR(NotFound, "empty priority queue") }
 
    return _heap_[0].first;
  }

References _heap_, _nb_elements_, and GUM_ERROR.

◆ toString()

template<typename Val, typename Priority, typename Cmp>

std::string gum::MultiPriorityQueue< Val, Priority, Cmp >::toString ( ) const

Displays the content of the queue.

Returns: Returns the content of the queue.

Definition at line 446 of file multiPriorityQueue_tpl.h.

                                                                     {
    bool              deja = false;
    std::stringstream stream;
    stream << "[";
 
    for (Size i = 0; i != _nb_elements_; ++i, deja = true) {
      if (deja) stream << " , ";
 
      stream << "(" << _heap_[i].first << " , " << *(_heap_[i].second) << ")";
    }
 
    stream << "]";
 
    return stream.str();
  }

Referenced by gum::operator<<().

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Member Data Documentation

◆ _cmp_

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

Cmp gum::MultiPriorityQueue< Val, Priority, Cmp >::_cmp_

private

Comparison function.

Definition at line 465 of file multiPriorityQueue.h.

Referenced by MultiPriorityQueue(), MultiPriorityQueue(), MultiPriorityQueue(), operator=(), operator=(), setPriorityByPos(), and setPriorityByPos().

◆ _heap_

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

std::vector< std::pair< Priority, const Val* > > gum::MultiPriorityQueue< Val, Priority, Cmp >::_heap_

private

An array storing all the elements of the heap as well as their score.

Definition at line 456 of file multiPriorityQueue.h.

Referenced by MultiPriorityQueue(), MultiPriorityQueue(), MultiPriorityQueue(), MultiPriorityQueue(), capacity(), clear(), eraseByPos(), operator=(), operator=(), pop(), priority(), resize(), setPriorityByPos(), setPriorityByPos(), top(), and topPriority().

◆ _indices_

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

HashTable< Val, std::vector< Size > > gum::MultiPriorityQueue< Val, Priority, Cmp >::_indices_

private

A hashtable for quickly finding the elements by their value.

Definition at line 459 of file multiPriorityQueue.h.

Referenced by MultiPriorityQueue(), MultiPriorityQueue(), MultiPriorityQueue(), MultiPriorityQueue(), allValues(), clear(), contains(), erase(), eraseByPos(), insert(), insert(), operator=(), operator=(), priority(), resize(), setPriority(), setPriorityByPos(), and setPriorityByPos().

◆ _nb_elements_

template<typename Val, typename Priority = int, typename Cmp = std::less< Priority >>

Size gum::MultiPriorityQueue< Val, Priority, Cmp >::_nb_elements_ {0}

private

The number of elements in the heap.

Definition at line 462 of file multiPriorityQueue.h.

462{0};

Referenced by MultiPriorityQueue(), MultiPriorityQueue(), clear(), empty(), eraseByPos(), operator=(), operator=(), operator[](), pop(), resize(), setPriorityByPos(), setPriorityByPos(), size(), top(), and topPriority().

The documentation for this class was generated from the following files:

agrum/base/core/multiPriorityQueue.h
agrum/base/core/multiPriorityQueue_tpl.h

Public Types

Public Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ const_pointer

◆ const_reference

◆ difference_type

◆ pointer

◆ reference

◆ value_type

Constructor & Destructor Documentation

◆ MultiPriorityQueue() [1/4]

◆ MultiPriorityQueue() [2/4]

◆ MultiPriorityQueue() [3/4]

◆ MultiPriorityQueue() [4/4]

◆ ~MultiPriorityQueue()

Member Function Documentation

◆ allValues()

◆ capacity()

◆ clear()

◆ contains()

◆ emplace()

◆ empty()

◆ erase()

◆ eraseByPos()

◆ eraseTop()

◆ insert() [1/2]

◆ insert() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator[]()

◆ pop()

◆ priority()

◆ resize()

◆ setPriority()

◆ setPriorityByPos() [1/2]

◆ setPriorityByPos() [2/2]

◆ size()

◆ top()

◆ topPriority()

◆ toString()

Member Data Documentation

◆ _cmp_

◆ _heap_

◆ _indices_

◆ _nb_elements_