/* -*- C++ -*-
*
* This file is a part of LEMON, a generic C++ optimization library
*
* Copyright (C) 2003-2008
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
* (Egervary Research Group on Combinatorial Optimization, EGRES).
*
* Permission to use, modify and distribute this software is granted
* provided that this copyright notice appears in all copies. For
* precise terms see the accompanying LICENSE file.
*
* This software is provided "AS IS" with no warranty of any kind,
* express or implied, and with no claim as to its suitability for any
* purpose.
*
*/
///\ingroup concept
///\file
///\brief Classes for representing heaps.
///
#ifndef LEMON_CONCEPT_HEAP_H
#define LEMON_CONCEPT_HEAP_H
#include
namespace lemon {
namespace concepts {
/// \addtogroup concept
/// @{
/// \brief A concept structure describes the main interface of heaps.
///
/// A concept structure describes the main interface of heaps.
///
template
class Heap {
public:
///\brief Type of the items stored in the heap.
typedef typename ItemIntMap::Key Item;
/// \brief Type to represent the items states.
///
/// Each Item element have a state associated to it. It may be "in heap",
/// "pre heap" or "post heap". The later two are indifferent from the
/// heap's point of view, but may be useful to the user.
///
/// The ItemIntMap _should_ be initialized in such way, that it maps
/// PRE_HEAP (-1) to any element to be put in the heap...
enum State {
IN_HEAP = 0,
PRE_HEAP = -1,
POST_HEAP = -2
};
/// \brief The constructor.
///
/// The constructor.
/// \param _iim should be given to the constructor, since it is used
/// internally to handle the cross references. The value of the map
/// should be PRE_HEAP (-1) for each element.
explicit Heap(ItemIntMap &_iim) {}
/// \brief The number of items stored in the heap.
///
/// Returns the number of items stored in the heap.
int size() const { return 0; }
/// \brief Checks if the heap stores no items.
///
/// Returns \c true if and only if the heap stores no items.
bool empty() const { return false; }
/// \brief Makes empty this heap.
///
/// Makes this heap empty.
void clear();
/// \brief Insert an item into the heap with the given heap.
///
/// Adds \c i to the heap with priority \c p.
/// \param i The item to insert.
/// \param p The priority of the item.
void push(const Item &i, const Prio &p) {}
/// \brief Returns the item with minimum priority.
///
/// This method returns the item with minimum priority.
/// \pre The heap must be nonempty.
Item top() const {}
/// \brief Returns the minimum priority.
///
/// It returns the minimum priority.
/// \pre The heap must be nonempty.
Prio prio() const {}
/// \brief Deletes the item with minimum priority.
///
/// This method deletes the item with minimum priority.
/// \pre The heap must be non-empty.
void pop() {}
/// \brief Deletes \c i from the heap.
///
/// This method deletes item \c i from the heap, if \c i was
/// already stored in the heap.
/// \param i The item to erase.
void erase(const Item &i) {}
/// \brief Returns the priority of \c i.
///
/// This function returns the priority of item \c i.
/// \pre \c i must be in the heap.
/// \param i The item.
Prio operator[](const Item &i) const {}
/// \brief \c i gets to the heap with priority \c p independently
/// if \c i was already there.
///
/// This method calls \ref push(\c i, \c p) if \c i is not stored
/// in the heap and sets the priority of \c i to \c p otherwise.
/// It may throw an \e UnderFlowPriorityException.
/// \param i The item.
/// \param p The priority.
void set(const Item &i, const Prio &p) {}
/// \brief Decreases the priority of \c i to \c p.
///
/// This method decreases the priority of item \c i to \c p.
/// \pre \c i must be stored in the heap with priority at least \c p.
/// \param i The item.
/// \param p The priority.
void decrease(const Item &i, const Prio &p) {}
/// \brief Increases the priority of \c i to \c p.
///
/// This method sets the priority of item \c i to \c p.
/// \pre \c i must be stored in the heap with priority at most \c
/// p relative to \c Compare.
/// \param i The item.
/// \param p The priority.
void increase(const Item &i, const Prio &p) {}
/// \brief Returns if \c item is in, has already been in, or has
/// never been in the heap.
///
/// This method returns PRE_HEAP if \c item has never been in the
/// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
/// otherwise. In the latter case it is possible that \c item will
/// get back to the heap again.
/// \param i The item.
State state(const Item &i) const {}
/// \brief Sets the state of the \c item in the heap.
///
/// Sets the state of the \c item in the heap. It can be used to
/// manually clear the heap when it is important to achive the
/// better time complexity.
/// \param i The item.
/// \param st The state. It should not be \c IN_HEAP.
void state(const Item& i, State st) {}
template
struct Constraints {
public:
void constraints() {
Item item;
Prio prio;
item=Item();
prio=Prio();
ignore_unused_variable_warning(item);
ignore_unused_variable_warning(prio);
typedef typename _Heap::State State;
State state;
ignore_unused_variable_warning(state);
_Heap heap1 = _Heap(map);
ignore_unused_variable_warning(heap1);
heap.push(item, prio);
prio = heap.prio();
item = heap.top();
heap.pop();
heap.set(item, prio);
heap.decrease(item, prio);
heap.increase(item, prio);
prio = heap[item];
heap.erase(item);
state = heap.state(item);
state = _Heap::PRE_HEAP;
state = _Heap::IN_HEAP;
state = _Heap::POST_HEAP;
heap.clear();
}
_Heap& heap;
ItemIntMap& map;
Constraints() : heap(0), map(0) {}
};
};
/// @}
} // namespace lemon
}
#endif // LEMON_CONCEPT_PATH_H