day02.rs

//! # I Was Told There Would Be No Math
//!
//! To extract the numbers when parsing the input we use our utility [`iter_unsigned`] and [`chunk`]
//! functions.
//!
//! Sorting the dimensions in ascending order makes calculating the smallest side or smallest
//! perimeter straightforward.
//!
//! [`iter_unsigned`]: crate::util::parse
//! [`chunk`]: crate::util::iter
use crate::util::iter::*;
use crate::util::parse::*;

type Gift = [u32; 3];

pub fn parse(input: &str) -> Vec<Gift> {
    input
        .iter_unsigned()
        .chunk::<3>()
        .map(|chunk| {
            let mut gift = chunk;
            gift.sort_unstable();
            gift
        })
        .collect()
}

pub fn part1(input: &[Gift]) -> u32 {
    input.iter().map(|[l, w, h]| 2 * (l * w + w * h + h * l) + l * w).sum()
}

pub fn part2(input: &[Gift]) -> u32 {
    input.iter().map(|[l, w, h]| 2 * (l + w) + (l * w * h)).sum()
}