Space-efficient geometric algorithms and data structures

By Ilya Katz and Hervé Brönnimann

inplaceds::block_tree_heap< SequenceIterator, Geometry, _Compare, _Compare_PQ, _Alloc > Class Template Reference

#include <block_tree_heap.hpp>

Collaboration diagram for inplaceds::block_tree_heap< SequenceIterator, Geometry, _Compare, _Compare_PQ, _Alloc >:

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Detailed Description

template<class SequenceIterator, class Geometry, class _Compare = std::less<typename SequenceIterator::value_type>, class _Compare_PQ = std::less<typename SequenceIterator::value_type>, class _Alloc = std::allocator<typename SequenceIterator::value_type>>
class inplaceds::block_tree_heap< SequenceIterator, Geometry, _Compare, _Compare_PQ, _Alloc >

A standard container made up of unique keys, which can be retrieved in logarithmic time.

Parameters:

	Key	Type of key objects.
	Compare	Comparison function object type for priority queue, defaults to less<Key>.
	Compare_PQ	Comparison function object type for binary search tree, defaults to less<Key>.
	Alloc	Allocator type, defaults to allocator<Key>.

my_tree_heap supports iterators. Keep these two things in mind if using iterators:

Only constant iterator generic operations are allowed since changes to data nodes may affect either or both priority queue and/or binary search tree
Iterator traverses in the order as defined by the binary search tree not the priority queue

There are some important prerequisites

block_tree_heap relies on RandomAccessIterator, that is the _Iter template parameter must conform to RandomAccessIterator [http://www.sgi.com/tech/stl/RandomAccessIterator.html]

block_tree_heap will not work if the data is modified while it is being processed by a function that depends on block_tree_heap

It is importnant not to get confused with iterator usage! c block_tree_heap nodes contain iterators that reference the original data. However, functions like successor and predecessor deal with the internal tree nodes, NOT the iterators from the original sequence

Todo:

TODO: clear()

TODO: copy contrucrs

TODO: change documentation

TODO: top() cannot return an interator beacuse top() is not necesarily in the BST - should return pointer

TODO: when doing BST swap, is it enouhg to just swap lines and do adjust_PQ

TODO: why is iterator not inherited

Definition at line 146 of file block_tree_heap.hpp.

Constructors

block_tree_heap (SequenceIterator f, SequenceIterator l, int b=1)

Builds a my_tree_heap from a range.

template<class RandomAccessIterator>

block_tree_heap (RandomAccessIterator first, RandomAccessIterator last, const _Compare &__comp, const _Compare_PQ &__comp_pq, const allocator_type &__a=allocator_type())

Builds a my_tree_heap from a range.

~block_tree_heap ()

block_tree_heap (const block_tree_heap< _Key, Geometry, _Compare, _Compare_PQ, _Alloc > &__x)

Public Types

typedef _Space_TH_Iterator<
DataNode > iterator

typedef std::iterator_traits<
SequenceIterator >::difference_type block_size_type

Iterator-related typedefs

typedef _Alloc::pointer pointer

typedef _Alloc::const_pointer const_pointer

typedef _Alloc::reference reference

typedef _Alloc::const_reference const_reference

typedef block::_Rb_tree< SequenceIterator,
DataNode, _M_KeyOfValue,
_M_key_comp,_M_key_comp_pq,
_Alloc > _Rep_type

typedef DataNode::event_type event_type

typedef DataNode::priority_type priority_type

typedef _Rep_type::const_iterator const_iterator

typedef _Rep_type::const_reverse_iterator reverse_iterator

typedef _Rep_type::const_reverse_iterator const_reverse_iterator

typedef _Rep_type::size_type size_type

typedef _Rep_type::difference_type difference_type

typedef _Rep_type::allocator_type allocator_type

Public Member Functions

tree_heap functions

void print ()

Prints pre-order traversal of PQ and BST.

SequenceIterator no_full_block ()

const iterator insert (SequenceIterator new_line)

void insert_into_gap (tree_iterator it, SequenceIterator new_line)

void update_left_most_pointer (tree_iterator it, int new_size)

value_type move_blocks (SequenceIterator first, SequenceIterator last)

Move all elements starting at in range [first,last] left by one element and place the first element in unprocessed segments section into first.

void update_top_pq (tree_iterator it)

DataNode & create_node (SequenceIterator l)

SequenceIterator get_gap (tree_iterator block)

SequenceIterator get_gap (const DataNode &block)

IF THIS IS CHNAGED ALSO NEED TO CHNAGE KEYOFVALUE.

void set_gap (tree_iterator block, SequenceIterator new_gap, block_size_type gap_size)

void set_gap (tree_iterator block, SequenceIterator new_gap)

SequenceIterator get_leftmost_gap (block_size_type size)

void swap_gaps (SequenceIterator b1, SequenceIterator b2, block_size_type size)

Swaps two blocks of sizes size.

block_size_type max_gap_size ()

Returns the size of the maximum gap.

void update_block_after_insert (tree_iterator &block, SequenceIterator new_el)

SequenceIterator get_top_pq (tree_iterator it)

void set_top_pq (tree_iterator it, SequenceIterator new_top)

event_type get_event (iterator block)

void pop ()

Removes an element that is located at the top of the queue from the queue and from BST.

iterator top () const

Returns pointer to the top of the priority queue.

priority_type get_priority (iterator block)

void segment_intersection_event (iterator it)

Performs intersection event operations on a line segment.

bool empty ()

Generic functions

key_compare key_comp () const

Returns the comparison object with which the my_tree_heap BST was constructed.

key_compare_pq key_comp_pq () const

Returns the comparison object with which the my_tree_heap PQ was constructed.

allocator_type get_allocator () const

Returns the allocator object with which the my_tree_heap was constructed.

const_iterator begin () const

Returns a read/write iterator that points to the first element in the my_tree_heap. Iteration is done in ascending order according to the keys.

iterator begin ()

const_iterator end () const

Returns a read/write iterator that points one past the last element in the my_tree_heap. Iteration is done in ascending order according to the keys.

iterator end ()

bool empty () const

size_type size () const

Returns the size of the my_tree_heap.

void clear ()

Erases all elements in a my_tree_heap.

Data Fields

_Rep_type _M_t

block_size_type block_size

SequenceIterator _M_last_in_th

specifies the element which is last element in tree/heap

tree_iterator _M_last_gap

tree_iterator * left_most_gap

Array that holds the pointer to the node that points to the leftmost gap of size x.

block_size_type * gaps_offsets

Array that hold offset to gaps.

_Compare _comp

BST coparison object.

_Compare_PQ _comp_pq

PQ comparison object.

Valid range

Specifies valid range for this tree/heap. This includes processed , partial and full tree/heap, and uprocessed blocks

SequenceIterator _M_first

SequenceIterator _M_last

Private Types

typedef _Rep_type::iterator tree_iterator

Public typedefs

typedef SequenceIterator::value_type _Key

typedef _Key key_type

typedef _Key value_type

typedef _Compare key_compare

typedef _Compare_PQ key_compare_pq

typedef key_type * key_ptr

typedef Geometry::point_type priority_type

Private Member Functions

iterator successor (iterator block)

SequenceIterator successor (tree_iterator node, SequenceIterator line)

Returns the successor of the line in the node or in the next one if line is the last element in this node.

iterator predecessor (iterator block)

void swap_lines (iterator a, iterator b)

Swaps two line segments in the BST.

void adjust_PQ (iterator it)

If a node's priority was chnaged, the PQ needs to be adjusted.

void erase (iterator __position)

Erases an element from a tree_heap (both from PQ and BST).

Data Structures

struct _M_key_comp

This is the functor that is passed to the rb_tree for comparisons of tree nodes. More...

struct _M_key_comp_pq

This is the functor that is passed to the rb_tree for comparisons of tree nodes. More...

struct _M_KeyOfValue

class _Space_TH_Iterator

Iterator class for the block_tree_heap. More...

struct DataNode

Defines nodes in the underlying rb-tree. DataNode is a structure that encapsulates information regarding a line segment and its event. Specifically it contains a SequenceIterator to the first active line segment of a block and its event and intersection line (if applicable). More...

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

block_tree_heap.hpp

Code Documentation generated Using Doxygen


Constructors
	block_tree_heap (SequenceIterator f, SequenceIterator l, int b=1)
	Builds a my_tree_heap from a range.
template<class RandomAccessIterator>
	block_tree_heap (RandomAccessIterator first, RandomAccessIterator last, const _Compare &__comp, const _Compare_PQ &__comp_pq, const allocator_type &__a=allocator_type())
	Builds a my_tree_heap from a range.
	~block_tree_heap ()
	block_tree_heap (const block_tree_heap< _Key, Geometry, _Compare, _Compare_PQ, _Alloc > &__x)
Public Types
typedef _Space_TH_Iterator< DataNode >	iterator
typedef std::iterator_traits< SequenceIterator >::difference_type	block_size_type
Iterator-related typedefs
typedef _Alloc::pointer	pointer
typedef _Alloc::const_pointer	const_pointer
typedef _Alloc::reference	reference
typedef _Alloc::const_reference	const_reference
typedef block::_Rb_tree< SequenceIterator, DataNode, _M_KeyOfValue, _M_key_comp,_M_key_comp_pq, _Alloc >	_Rep_type
typedef DataNode::event_type	event_type
typedef DataNode::priority_type	priority_type
typedef _Rep_type::const_iterator	const_iterator
typedef _Rep_type::const_reverse_iterator	reverse_iterator
typedef _Rep_type::const_reverse_iterator	const_reverse_iterator
typedef _Rep_type::size_type	size_type
typedef _Rep_type::difference_type	difference_type
typedef _Rep_type::allocator_type	allocator_type
Public Member Functions
tree_heap functions
void	print ()
	Prints pre-order traversal of PQ and BST.
SequenceIterator	no_full_block ()
const iterator	insert (SequenceIterator new_line)
void	insert_into_gap (tree_iterator it, SequenceIterator new_line)
void	update_left_most_pointer (tree_iterator it, int new_size)
value_type	move_blocks (SequenceIterator first, SequenceIterator last)
	Move all elements starting at in range [first,last] left by one element and place the first element in unprocessed segments section into `first`.
void	update_top_pq (tree_iterator it)
DataNode &	create_node (SequenceIterator l)
SequenceIterator	get_gap (tree_iterator block)
SequenceIterator	get_gap (const DataNode &block)
	IF THIS IS CHNAGED ALSO NEED TO CHNAGE KEYOFVALUE.
void	set_gap (tree_iterator block, SequenceIterator new_gap, block_size_type gap_size)
void	set_gap (tree_iterator block, SequenceIterator new_gap)
SequenceIterator	get_leftmost_gap (block_size_type size)
void	swap_gaps (SequenceIterator b1, SequenceIterator b2, block_size_type size)
	Swaps two blocks of sizes `size`.
block_size_type	max_gap_size ()
	Returns the size of the maximum gap.
void	update_block_after_insert (tree_iterator &block, SequenceIterator new_el)
SequenceIterator	get_top_pq (tree_iterator it)
void	set_top_pq (tree_iterator it, SequenceIterator new_top)
event_type	get_event (iterator block)
void	pop ()
	Removes an element that is located at the top of the queue from the queue and from BST.
iterator	top () const
	Returns pointer to the top of the priority queue.
priority_type	get_priority (iterator block)
void	segment_intersection_event (iterator it)
	Performs intersection event operations on a line segment.
bool	empty ()
Generic functions
key_compare	key_comp () const
	Returns the comparison object with which the my_tree_heap BST was constructed.
key_compare_pq	key_comp_pq () const
	Returns the comparison object with which the my_tree_heap PQ was constructed.
allocator_type	get_allocator () const
	Returns the allocator object with which the my_tree_heap was constructed.
const_iterator	begin () const
	Returns a read/write iterator that points to the first element in the my_tree_heap. Iteration is done in ascending order according to the keys.
iterator	begin ()
const_iterator	end () const
	Returns a read/write iterator that points one past the last element in the my_tree_heap. Iteration is done in ascending order according to the keys.
iterator	end ()
bool	empty () const
size_type	size () const
	Returns the size of the my_tree_heap.
void	clear ()
	Erases all elements in a my_tree_heap.
Data Fields
_Rep_type	_M_t
block_size_type	block_size
SequenceIterator	_M_last_in_th
	specifies the element which is last element in tree/heap
tree_iterator	_M_last_gap
tree_iterator *	left_most_gap
	Array that holds the pointer to the node that points to the leftmost gap of size `x`.
block_size_type *	gaps_offsets
	Array that hold offset to gaps.
_Compare	_comp
	BST coparison object.
_Compare_PQ	_comp_pq
	PQ comparison object.
Valid range
Specifies valid range for this tree/heap. This includes processed , partial and full tree/heap, and uprocessed blocks
SequenceIterator	_M_first
SequenceIterator	_M_last
Private Types
typedef _Rep_type::iterator	tree_iterator
Public typedefs
typedef SequenceIterator::value_type	_Key
typedef _Key	key_type
typedef _Key	value_type
typedef _Compare	key_compare
typedef _Compare_PQ	key_compare_pq
typedef key_type *	key_ptr
typedef Geometry::point_type	priority_type
Private Member Functions
iterator	successor (iterator block)
SequenceIterator	successor (tree_iterator node, SequenceIterator line)
	Returns the successor of the `line` in the `node` or in the next one if `line` is the last element in this node.
iterator	predecessor (iterator block)
void	swap_lines (iterator a, iterator b)
	Swaps two line segments in the BST.
void	adjust_PQ (iterator it)
	If a node's priority was chnaged, the PQ needs to be adjusted.
void	erase (iterator __position)
	Erases an element from a tree_heap (both from PQ and BST).
Data Structures
struct	_M_key_comp
	This is the functor that is passed to the rb_tree for comparisons of tree nodes. More...
struct	_M_key_comp_pq
	This is the functor that is passed to the rb_tree for comparisons of tree nodes. More...
struct	_M_KeyOfValue
class	_Space_TH_Iterator
	Iterator class for the block_tree_heap. More...
struct	DataNode
	Defines nodes in the underlying rb-tree. DataNode is a structure that encapsulates information regarding a line segment and its event. Specifically it contains a `SequenceIterator` to the first active line segment of a block and its event and intersection line (if applicable). More...