#![allow(dead_code)]
#![allow(unused_variables)]
#![allow(unused_mut)]
use std::fs::File;
use std::io::Read;

fn main() {
    // let filename = "in/day04.ref";
    let filename = "in/day04.pzl";

    let mut f = File::open(filename).expect("cannot open file");
    let mut content = String::new();
    f.read_to_string(&mut content).expect("cannot read file");
    let lines: Vec<_> = content.trim_end().split('\n').collect();
    // println!("{:?}", lines);

    let mut res1 = 0;

    let mut copies = vec![1; lines.len()];

    for (i, line) in lines.into_iter().enumerate() {
        let (first, rest) = line.split_once(":").unwrap();
        let game_num = first.split_once(" ").unwrap().1;
        let (win, actual) = rest.split_once("|").unwrap();

        let parse = |a: &str| {
            a.split(" ")
                .filter_map(|x| x.parse().ok())
                .collect::<Vec<u32>>()
        };

        let count = parse(actual)
            .iter()
            .filter(|x| parse(win).contains(x))
            .count();

        if count > 0 {
            res1 += 1 << (count - 1);
        }

        for j in i..i + count {
            copies[j + 1] += copies[i];
        }
    }

    let res2: u32 = copies.iter().sum();

    println!("res1: {}", res1);
    println!("res2: {}", res2);
    assert_eq!(res1, 21919);
    assert_eq!(res2, 9881048);
}