Advent of Code 2021 - Day 7: The Treachery of Whales

the_treachery_of_whales.rs

fn align(positions: &[i64]) -> i64 {
    (*positions.iter().min().unwrap()..=*positions.iter().max().unwrap())
        .map(|target| positions.iter().map(|&p| (p - target).abs()).sum())
        .min()
        .unwrap()
}

fn align2(positions: &[i64]) -> i64 {
    (*positions.iter().min().unwrap()..=*positions.iter().max().unwrap())
        .map(|target| {
            positions
                .iter()
                .map(|&p| {
                    let diff = (p - target).abs();
                    (diff.pow(2) + diff) / 2
                })
                .sum()
        })
        .min()
        .unwrap()
}