AdventOfCode2022/04/main.rs

#![allow(dead_code)]
use std::fs::File;
use std::io;
use std::io::BufRead;
use std::path::Path;
use std::time::Instant;

fn main() {
    let now = Instant::now();
    part_one();
    let part_one_duration = now.elapsed();
    part_two();
    let part_two_duration = now.elapsed();
    println!(
        "p1: {}ms, p2: {}ms",
        part_one_duration.as_millis(),
        (part_two_duration - part_one_duration).as_millis()
    );
}

fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
where
    P: AsRef<Path>,
{
    // note that this discards a final newline
    let file = File::open(filename)?;
    Ok(io::BufReader::new(file).lines())
}

fn part_one() {
    if let Ok(lines) = read_lines("./inputs/input") {
        let mut overlaps = 0;
        for line in lines {
            if let Ok(ranges) = line {
                let v: Vec<Vec<i8>> = ranges
                    .split(",")
                    .map(|r| r.split("-").map(|i| i.parse::<i8>().unwrap()).collect())
                    .collect();
                // 00 ... 01
                // 10 ... 11
                if (v[0][0] <= v[1][0] && v[0][1] >= v[1][1])
                    || (v[1][0] <= v[0][0] && v[1][1] >= v[0][1])
                {
                    overlaps += 1;
                }
            }
        }
        println!("{}", overlaps);
    }
}

fn part_two() {
    if let Ok(lines) = read_lines("./inputs/input") {
        let mut overlaps = 0;
        for line in lines {
            if let Ok(ranges) = line {
                let v: Vec<Vec<i8>> = ranges
                    .split(",")
                    .map(|r| r.split("-").map(|i| i.parse::<i8>().unwrap()).collect())
                    .collect();
                // 00 ... 01
                // 10 ... 11
                // uuuuuugh
                if (v[0][0] <= v[1][0] && v[0][1] >= v[1][1])
                    || (v[1][0] <= v[0][0] && v[1][1] >= v[0][1])
                    || (v[0][0] <= v[1][1] && v[0][0] >= v[1][0])
                    || (v[0][1] >= v[1][0] && v[0][1] <= v[1][1])
                {
                    overlaps += 1;
                }
            }
        }
        println!("{}", overlaps);
    }
}