Very bad performance with duplicate value

[Stargateur]

I did some benchmark and find out the the sort have terrible performance with duplicate value

#[bench]
fn lazysort(b: &mut Bencher) {
    b.iter(|| {
        use lazysort::Sorted;
        let mut rng = thread_rng();
        let v: Vec<i32> = std::iter::repeat_with(|| rng.gen_range(0, 2))
            .take(10000)
            .collect();
        let _: Vec<_> = v.iter().sorted().take(1).collect();
    })
}

You should implement the quick sort using the 3-ways method.