use std::{fs, env};

fn read_input(path: &str) -> String {
    return fs::read_to_string(path).expect("Cannot read file.");
}

fn parse_input(s: &str) -> Vec<i32> {
    return s.replace("\n", "").split(",")
        .filter_map(|e| e.parse::<i32>().ok()).collect();
}

fn smart_compute_x_days(v: &Vec<i32>, x: i32) -> i128 {
    let mut l: Vec<i128> = vec![0;9];
    for i in v {
        l[*i as usize] += 1;
    }

    for _d in 1..=x {
        let n = l[0];
        for i in 1..9 {
            l[i - 1] = l[i];
        }
        l[6] += n;
        l[8] = n;
    }
    return l.iter().sum();
}

fn main() {
    let args: Vec<String> = env::args().collect();
    for arg in args.iter().skip(1) {
        let vec_in = parse_input(&read_input(&arg));
        println!("[{}]", &arg);
        println!("\t[Part 1] => Answer is '{}'.", smart_compute_x_days(&vec_in, 80));
        println!("\t[Part 2] => Answer is '{}'.", smart_compute_x_days(&vec_in, 256));
    }
}