AOC Day 1

day1.rs

use crate::util::util;
use std::vec::Vec;

pub fn execute() {
    let filename = String::from("day1.txt");
    let masses: Vec<u32> = util::read_file(filename);
    println!("Part one answer: {}", part_one(&masses));
    println!("Part two answer: {}", part_two(&masses));
}

fn part_one(masses: &Vec<u32>) -> u32 {
    return masses.iter().map(|mass| calculate_fuel(*mass)).sum();
}

fn calculate_fuel(mass: u32) -> u32 {
    return (mass / 3).saturating_sub(2);
}

fn part_two(masses: &Vec<u32>) -> u32 {
    let mut sum: u32 = 0;
    for mass in masses {
        let mut result: u32 = *mass;
        while result > 0 {
            result = calculate_fuel(result);
            sum += result;
        }
    }
    return sum;
}