Function persistent_h0 

pub fn persistent_h0(
    dist: &[f64],
    n: usize,
    epsilons: &[f64],
    out_b0: &mut [usize],
) -> usize

Persistent 0-dim homology: write the Betti-0 (component count) at each scale in epsilons (assumed increasing) into out_b0 — the barcode of connected features (born at ε=0, dying as they merge; b0 is monotonically non-increasing). Returns the count written. Zero-heap.