sdsl::wt_rlg< RankSupport, WaveletTree > Class Template Reference

A Wavelet Tree class for byte sequences. More...

#include <wt_rlg.hpp>

List of all members.

Public Types
typedef int_vector::size_type	size_type
typedef unsigned char	value_type
typedef RankSupport	rank_support_type
typedef WaveletTree	wt_type
Public Member Functions
	wt_rlg (const unsigned char *rac, size_type size)
	Constructor.
template<class size_type_class >
	wt_rlg (int_vector_file_buffer< 8, size_type_class > &rac, size_type size)
template<class size_type_class >
void	construct (int_vector_file_buffer< 8, size_type_class > &rac, size_type size)
	Construct the wavelet tree from a random access container.
	wt_rlg (const wt_rlg &wt)
	Copy constructor.
wt_rlg &	operator= (const wt_rlg &wt)
	Assignment operator.
void	swap (wt_rlg &wt)
	Swap operator.
size_type	size () const
	Returns the size of the original vector.
bool	empty () const
	Returns whether the wavelet tree contains no data.
value_type	operator[] (size_type i) const
	Recovers the ith symbol of the original vector.
size_type	rank (size_type i, value_type c) const
	Calculates how many symbols c are in the prefix [0..i-1] of the supported vector.
size_type	rank_ith_symbol (size_type i, value_type &c) const
	Calculates how many occurrences of symbol wt[i] are in the prefix [0..i-1] of the supported sequence.
size_type	select (size_type i, value_type c) const
	Calculates the ith occurrence of the symbol c in the supported vector.
size_type	serialize (std::ostream &out, structure_tree_node *v=NULL, std::string name="") const
	Serializes the data structure into the given ostream.
void	load (std::istream &in)
	Loads the data structure from the given istream.
Public Attributes
const uint16_t &	sigma

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Detailed Description

template<class RankSupport = rank_support_v5<>, class WaveletTree = wt_without_select>
class sdsl::wt_rlg< RankSupport, WaveletTree >

A Wavelet Tree class for byte sequences.

A wavelet tree is build for a vector of characters over the alphabet . This class should be used only for small alphabets (see wt_int for a wavelet tree for big alphabets). The wavelet tree consists of a tree of bitvectors and provides three efficient methods:

• The "[]"-operator: returns the ith symbol of vector for which the wavelet tree was build for.
• The rank method: returns the number of occurences of symbol in the prefix [0..i-1] in the vector for which the wavelet tree was build for.

• The select method: returns the index of the jth occurence of symbol .

  Space complexity

  bits, where is the size of the vector the wavelet tree was build for.

  Note

  We denote the length of the longest run in the sequence with

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Constructor & Destructor Documentation

template<class RankSupport = rank_support_v5<>, class WaveletTree = wt_without_select>

sdsl::wt_rlg< RankSupport, WaveletTree >::wt_rlg	(	const unsigned char *	rac,
		size_type	size
	)		[inline]

Constructor.

   \param rac Reference to the vector (or unsigned char array) for which the wavelet tree should be build.
   \param size Size of the prefix of the vector (or unsigned char array) for which the wavelet tree should be build.
   \par Time complexity

, where

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Member Function Documentation

template<class RankSupport = rank_support_v5<>, class WaveletTree = wt_without_select>

template<class size_type_class >

void sdsl::wt_rlg< RankSupport, WaveletTree >::construct	(	int_vector_file_buffer< 8, size_type_class > &	rac,
		size_type	size
	)		[inline]

Construct the wavelet tree from a random access container.

Parameters:

rac	A random access container
size	The length of the prefix of the random access container, for which the wavelet tree should be build

template<class RankSupport = rank_support_v5<>, class WaveletTree = wt_without_select>

value_type sdsl::wt_rlg< RankSupport, WaveletTree >::operator[]

(

size_type

i

)

const [inline]

Recovers the ith symbol of the original vector.

Parameters:

i	The index of the symbol in the original vector.

Returns:

The ith symbol of the original vector.

Time complexity

on average, where is the zero order entropy of the sequence and the maximal length of a run in the sequence.

template<class RankSupport = rank_support_v5<>, class WaveletTree = wt_without_select>

size_type sdsl::wt_rlg< RankSupport, WaveletTree >::rank	(	size_type	i,
		value_type	c
	)		const [inline]

Calculates how many symbols c are in the prefix [0..i-1] of the supported vector.

Parameters:

i	The exclusive index of the prefix range [0..i-1], so .
c	The symbol to count the occurrences in the prefix.

Returns:

The number of occurrences of symbol c in the prefix [0..i-1] of the supported vector.

Time complexity

on average, where is the zero order entropy of the sequence and the maximal length of a run of s in the sequence.

template<class RankSupport = rank_support_v5<>, class WaveletTree = wt_without_select>

size_type sdsl::wt_rlg< RankSupport, WaveletTree >::rank_ith_symbol	(	size_type	i,
		value_type &	c
	)		const [inline]

Calculates how many occurrences of symbol wt[i] are in the prefix [0..i-1] of the supported sequence.

   \param i The index of the symbol.

Parameters:

c	Reference that will contain the symbol at position i after the execution of the method.

Returns:

The number of occurrences of symbol wt[i] in the prefix [0..i-1]

Time complexity

template<class RankSupport = rank_support_v5<>, class WaveletTree = wt_without_select>

size_type sdsl::wt_rlg< RankSupport, WaveletTree >::select	(	size_type	i,
		value_type	c
	)		const [inline]

Calculates the ith occurrence of the symbol c in the supported vector.

Parameters:

i	The ith occurrence. .
c	The symbol c.

Time complexity

on average, where is the zero order entropy of the sequence and the maximal length of a run of s in the sequence.

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

• sdsl/include/sdsl/wt_rlg.hpp