aoc19/src/day_1.rs

fn total_fuel(mass: f32) -> i32 {
    let mut req_fuel = get_fuel_cost(mass);
    let mut fuel = req_fuel;
    while get_fuel_cost(req_fuel as f32) > 0{
        req_fuel = get_fuel_cost(req_fuel as f32);
        fuel += req_fuel;
    }

    fuel
}

fn get_fuel_cost(mass: f32) -> i32{
    ((mass / 3.0).floor() - 2.0) as i32
}

pub fn main() {

    let contents = std::fs::read_to_string("input_day_1.txt").expect("Scream Internally");
    let lines = contents.split("\r\n");
    let mut all_f = 0;
    for l in lines {
        let x: f32 = l.parse().unwrap();
        all_f += total_fuel(x);
    }

    println!("{}", all_f); 
}