use std::error::Error;
use std::fs::File;
use std::io::{self, BufRead};
use std::vec::Vec;

fn main() -> Result<(), Box<dyn Error>> {
    let file = File::open("inputs/day13.txt")?;
    let mut lines = io::BufReader::new(file).lines().map(|l| l.unwrap());

    let depature_time: u32 = lines.nth(0).unwrap().parse().unwrap();
    let buses: Vec<u32> = lines
        .nth(0)
        .unwrap()
        .split(',')
        .filter_map(|b| b.parse().ok())
        .collect();

    let times: Vec<(u32, u32)> = buses
        .iter()
        .map(|b| (*b, b - (depature_time % b)))
        .collect();

    let best_time = times
        .iter()
        .fold(times[0], |a, b| if a.1 < b.1 { a } else { *b });

    println!("Line: {}, Wait Time: {}", best_time.0, best_time.1);
    println!("Answer: {}", best_time.0 * best_time.1);

    Ok(())
}