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BinaryHeapM Class Reference

Binary heap implementation. More...

Detailed Description

Binary heap implementation.

Binary heaps are really fast for ordering nodes in a way that makes it possible to get the node with the lowest F score. Also known as a priority queue.

This has actually been rewritten as a d-ary heap (by default a 4-ary heap) for performance, but it's the same principle.

See Also
http://en.wikipedia.org/wiki/Binary_heap
https://en.wikipedia.org/wiki/D-ary_heap

Classes

struct  Tuple
 

Public Member Functions

 BinaryHeapM (int numberOfElements)
 
void Add (PathNode node)
 Adds a node to the heap.
 
void Clear ()
 
void Rebuild ()
 Rebuilds the heap by trickeling down all items.
 
PathNode Remove ()
 Returns the node with the lowest F score from the heap.
 

Public Attributes

float growthFactor = 2
 The tree will grow by at least this factor every time it is expanded.
 
int numberOfItems
 Number of items in the tree.
 

Package Functions

PathNode GetNode (int i)
 
void SetF (int i, uint f)
 

Private Member Functions

void Validate ()
 

Private Attributes

Tuple[] binaryHeap
 Internal backing array for the tree.
 
const int D = 4
 Number of children of each node in the tree.
 
const bool SortGScores = true
 Sort nodes by G score if there is a tie when comparing the F score.
 

Constructor & Destructor Documentation

BinaryHeapM ( int  numberOfElements)

Member Function Documentation

void Add ( PathNode  node)

Adds a node to the heap.

void Clear ( )
PathNode GetNode ( int  i)
package
void Rebuild ( )

Rebuilds the heap by trickeling down all items.

Usually called after the hTarget on a path has been changed

PathNode Remove ( )

Returns the node with the lowest F score from the heap.

void SetF ( int  i,
uint  f 
)
package
void Validate ( )
private

Member Data Documentation

Tuple [] binaryHeap
private

Internal backing array for the tree.

const int D = 4
private

Number of children of each node in the tree.

Different values have been tested and 4 has been empirically found to perform the best.

See Also
https://en.wikipedia.org/wiki/D-ary_heap
float growthFactor = 2

The tree will grow by at least this factor every time it is expanded.

int numberOfItems

Number of items in the tree.

const bool SortGScores = true
private

Sort nodes by G score if there is a tie when comparing the F score.

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