Function quadratic_sieve 

pub fn quadratic_sieve(
    n: &BigInt,
    b: u64,
    m_interval: usize,
) -> Option<(BigInt, BigInt)>

The quadratic sieve (see the module note above): factor N by log-sieving Q(x) = (⌈√N⌉+x)² − N over [0, m_interval) against the factor base of primes ≤ b for which N is a quadratic residue, then combining smooth relations through a GF(2) dependency. Returns (p, q) or None.