use std::env::args;
use std::fs::File;
use std::io::BufRead;
use std::io::BufReader;

pub fn iter_input() -> impl Iterator<Item = String> {
    let path = args().nth(1).unwrap();
    let file = File::open(path).unwrap();
    return BufReader::new(file).lines().map(|l| l.unwrap());
}

#[allow(dead_code)]
pub fn div_floor(a: i64, b: i64) -> i64 {
    let x = a / b;
    if (b > 0 && x * b > a) || (b < 0 && x * b < a) {
        return x - 1;
    } else {
        return x;
    }
}