aoc3.rs

extern crate regex;
#[macro_use] extern crate lazy_static;

struct Claim {
    i: usize,
    x: usize,
    y: usize,
    l: usize,
    h: usize
}

fn parse(s: &str) -> Claim {
    lazy_static! {
        static ref REGEX: regex::Regex = regex::Regex::new(r"#(\d+) @ (\d+),(\d+): (\d+)x(\d+)").unwrap();
    }
    let findings = REGEX.captures(s).unwrap();
    Claim {
        i: findings.get(1).unwrap().as_str().parse::<usize>().unwrap(),
        x: findings.get(2).unwrap().as_str().parse::<usize>().unwrap(),
        y: findings.get(3).unwrap().as_str().parse::<usize>().unwrap(),
        l: findings.get(4).unwrap().as_str().parse::<usize>().unwrap(),
        h: findings.get(5).unwrap().as_str().parse::<usize>().unwrap()
    }
}

fn claim(c: Claim, canvas: &mut[[u8; 1000]; 1000]) {
    for x in c.x..(c.x+c.l) {
        for y in c.y..(c.y+c.h) {
            canvas[x][y] += 1;
        }
    }
}

fn main() {
    //Create an empty 1000x1000 canvas
    let mut canvas: [[u8; 1000]; 1000] = [[0; 1000]; 1000];
    //Read the file in the string
    let contents = std::fs::read_to_string("input.txt").unwrap();
    //Split the string into multiple rows
    let rows = contents.split('\n');
    //For each row
    for row in rows {
        let c: Claim = parse(&row);
        claim(c, &mut canvas);
    }
    let mut count: usize = 0;
    for x in 0..1000 {
        for y in 0..1000 {
            if canvas[x][y] >= 2 {
                count += 1;
            }            
        }
    }
    println!("{}", count);
}