use std::{
    collections::HashMap,
    fs::File,
    io::{BufRead, BufReader},
};

#[allow(dead_code)]
fn day1_1() {
    let reader = BufReader::new(File::open("input.txt").unwrap());
    let mut a = Vec::<i32>::new();
    let mut b = Vec::<i32>::new();
    for line in reader.lines() {
        let line = line.unwrap();
        let (a1, b1) = line.trim_end().split_once("   ").unwrap();
        a.push(a1.parse().unwrap());
        b.push(b1.parse().unwrap());
    }
    a.sort_unstable();
    b.sort_unstable();
    let result: i32 = a.into_iter().zip(b).map(|(a, b)| (a - b).abs()).sum();
    println!("{result}");
}

#[allow(dead_code)]
fn day1_2() {
    let reader = BufReader::new(File::open("input.txt").unwrap());
    let mut a = Vec::<u32>::new();
    let mut b = HashMap::<u32, u32>::new();
    for line in reader.lines() {
        let line = line.unwrap();
        let (a1, b1) = line.trim_end().split_once("   ").unwrap();
        a.push(a1.parse().unwrap());
        *b.entry(b1.parse().unwrap()).or_insert(0) += 1;
    }
    let result: u32 = a.into_iter().map(|a| a * *b.get(&a).unwrap_or(&0)).sum();
    println!("{result}");
}

fn main() {
    day1_1();
    day1_2();
}