use std::iter::zip;

#[path = "../lib.rs"] mod lib;

fn part1(list1: &Vec<u32>, list2: &Vec<u32>) -> u32 {
    return zip(list1.iter(), list2.iter()).map(|(a, b)| a.abs_diff(*b)).sum();
}

fn part2(list1: &Vec<u32>, list2: &Vec<u32>) -> u32 {
    let n = list1.len();
    let mut v = 0;
    let mut i1 = 0;
    let mut i2 = 0;
    let mut k1 = 0;
    let mut k2 = 0;
    let mut sum = 0;

    while i1 < n && i2 < n {
        if v == 0 {
            if list1[i1] == list2[i2] {
                v = list1[i1];
                k1 = 1;
                k2 = 1;
                i1 += 1;
                i2 += 1;
            } else if list1[i1] < list2[i2] {
                i1 += 1;
            } else {
                i2 += 1;
            }
        } else {
            if v == list1[i1] {
                i1 += 1;
                k1 += 1;
            } else if v == list2[i2] {
                i2 += 1;
                k2 += 1;
            } else {
                sum += v * k1 * k2;
                v = 0;
            }
        }
    }

    sum += v * k1 * k2;

    return sum;
}

fn main() {
    let mut list1 = vec![];
    let mut list2 = vec![];

    for line in lib::iter_input() {
        let (left, right) = line.split_once("   ").unwrap();
        list1.push(left.parse::<u32>().unwrap());
        list2.push(right.parse::<u32>().unwrap());
    }

    list1.sort();
    list2.sort();

    println!("part1: {}", part1(&list1, &list2));
    println!("part2: {}", part2(&list1, &list2));
}