AoC Day 2

main.rs

use std::env;
use std::fs::File;
use std::io::prelude::*;
use std::io::BufReader;

fn main() {
    let args: Vec<String> = env::args().collect();

    let filename = &args[1];

    println!("Using file {}", filename);

    let f = BufReader::new(File::open(filename)
        .expect("File not found"));

    let mut checksum = 0;
    let mut divs = 0;
    for line in f.lines() {
        let line = line.unwrap();
        let values = line.split_whitespace().map(|x| x.parse::<u32>().unwrap());
        let mut values: Vec<u32> = values.collect();
        values.sort();

        checksum += part1(&values);
        divs += part2(&values);
    }

    println!("Checksum: {}", checksum);
    println!("Divs: {}", divs);

}

fn part1(values: &Vec<u32>) -> u32 {
    values[values.len() - 1] - values[0]
}

fn part2(values: &Vec<u32>) -> u32 {
    for i in 0..values.len() {
        let candidate = values[values.len() - 1 - i];
        for j in i+1..values.len() {
            let divisor = values[values.len() - 1 - j];
            if candidate % divisor == 0 {
                return candidate / divisor;
            }
        }
    }
    println!("OH NOES");
    0
}