This class implements the D-ary heap data structure. It fully conforms to the heap concept.
The D-ary heap is a generalization of the binary heap structure, its nodes have at most D children, instead of two. BinHeap and QuadHeap are specialized implementations of this structure for D=2 and D=4, respectively.
| PR | Type of the priorities of the items. |
| IM | A read-writable item map with int values, used internally to handle the cross references. |
| D | The degree of the heap, each node have at most D children. The default is 16. Powers of two are suggested to use so that the multiplications and divisions needed to traverse the nodes of the heap could be performed faster. |
| CMP | A functor class for comparing the priorities. The default is std::less<PR>. |
#include <lemon/dheap.h>
Public Types | |
| enum | State { IN_HEAP = 0, PRE_HEAP = -1, POST_HEAP = -2 } |
| Type to represent the states of the items. More... | |
| typedef IM | ItemIntMap |
| Type of the item-int map. | |
| typedef PR | Prio |
| Type of the priorities. | |
| typedef ItemIntMap::Key | Item |
| Type of the items stored in the heap. | |
| typedef std::pair< Item, Prio > | Pair |
| Type of the item-priority pairs. | |
| typedef CMP | Compare |
| Functor type for comparing the priorities. | |
Public Member Functions | |
| DHeap (ItemIntMap &map) | |
| Constructor. More... | |
| DHeap (ItemIntMap &map, const Compare &comp) | |
| Constructor. More... | |
| int | size () const |
| The number of items stored in the heap. More... | |
| bool | empty () const |
| Check if the heap is empty. More... | |
| void | clear () |
| Make the heap empty. More... | |
| void | push (const Pair &p) |
| Insert a pair of item and priority into the heap. More... | |
| void | push (const Item &i, const Prio &p) |
| Insert an item into the heap with the given priority. More... | |
| Item | top () const |
| Return the item having minimum priority. More... | |
| Prio | prio () const |
| The minimum priority. More... | |
| void | pop () |
| Remove the item having minimum priority. More... | |
| void | erase (const Item &i) |
| Remove the given item from the heap. More... | |
| Prio | operator[] (const Item &i) const |
| The priority of the given item. More... | |
| void | set (const Item &i, const Prio &p) |
| Set the priority of an item or insert it, if it is not stored in the heap. More... | |
| void | decrease (const Item &i, const Prio &p) |
| Decrease the priority of an item to the given value. More... | |
| void | increase (const Item &i, const Prio &p) |
| Increase the priority of an item to the given value. More... | |
| State | state (const Item &i) const |
| Return the state of an item. More... | |
| void | state (const Item &i, State st) |
| Set the state of an item in the heap. More... | |
| void | replace (const Item &i, const Item &j) |
| Replace an item in the heap. More... | |
| enum State |
Each item has a state associated to it. It can be "in heap", "pre-heap" or "post-heap". The latter two are indifferent from the heap's point of view, but may be useful to the user.
The item-int map must be initialized in such way that it assigns PRE_HEAP (-1) to any element to be put in the heap.
| Enumerator | |
|---|---|
| IN_HEAP |
= 0. |
| PRE_HEAP |
= -1. |
| POST_HEAP |
= -2. |
|
inlineexplicit |
Constructor.
| map | A map that assigns int values to the items. It is used internally to handle the cross references. The assigned value must be PRE_HEAP (-1) for each item. |
|
inline |
Constructor.
| map | A map that assigns int values to the items. It is used internally to handle the cross references. The assigned value must be PRE_HEAP (-1) for each item. |
| comp | The function object used for comparing the priorities. |
|
inline |
This function returns the number of items stored in the heap.
|
inline |
This function returns true if the heap is empty.
|
inline |
This functon makes the heap empty. It does not change the cross reference map. If you want to reuse a heap that is not surely empty, you should first clear it and then you should set the cross reference map to PRE_HEAP for each item.
|
inline |
This function inserts p.first to the heap with priority p.second.
| p | The pair to insert. |
p.first must not be stored in the heap. This function inserts the given item into the heap with the given priority.
| i | The item to insert. |
| p | The priority of the item. |
|
inline |
This function returns the item having minimum priority.
|
inline |
This function returns the minimum priority.
|
inline |
This function removes the item having minimum priority.
|
inline |
This function removes the given item from the heap if it is already stored.
| i | The item to delete. |
This function returns the priority of the given item.
| i | The item. |
This method sets the priority of the given item if it is already stored in the heap. Otherwise it inserts the given item into the heap with the given priority.
| i | The item. |
| p | The priority. |
This function decreases the priority of an item to the given value.
| i | The item. |
| p | The priority. |
This function increases the priority of an item to the given value.
| i | The item. |
| p | The priority. |
This method returns PRE_HEAP if the given 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 the item will get back to the heap again.
| i | The item. |
This function sets the state of the given item in the heap. It can be used to manually clear the heap when it is important to achive better time complexity.
| i | The item. |
| st | The state. It should not be IN_HEAP. |
1.8.5