Struct WaveletMatrix 

pub struct WaveletMatrix { /* private fields */ }

A wavelet matrix over an integer alphabet [0, σ).

Supports access, rank, and select queries in O(log σ) time using ⌈log₂ σ⌉ levels of RankSelectBitVecs.

Implementations

impl WaveletMatrix

pub fn build(symbols: &[usize], sigma: usize) -> Result<Self>

Build a wavelet matrix from a sequence of symbols in [0, sigma).

Errors

Returns an error if any symbol is ≥ sigma or sigma is 0.

pub fn access(&self, i: usize) -> Option<usize>

Access the symbol at position i.

Returns None if i >= len.

pub fn rank(&self, c: usize, i: usize) -> usize

Count occurrences of symbol c in positions [0, i).

pub fn select(&self, c: usize, k: usize) -> Option<usize>

Find the position of the k-th occurrence of symbol c (1-indexed).

Returns None if there are fewer than k occurrences.

pub fn len(&self) -> usize

Length of the indexed sequence.

pub fn is_empty(&self) -> bool

Whether the sequence is empty.

pub fn sigma(&self) -> usize

Alphabet size.

Trait Implementations

impl Clone for WaveletMatrix

fn clone(&self) -> WaveletMatrix

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WaveletMatrix

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.