use std::error::Error;
use std::fs::File;
use std::io::{self, BufRead};
use std::vec::Vec;

fn main() -> Result<(), Box<dyn Error>> {
    let file = File::open("inputs/day3.txt")?;
    let lines = io::BufReader::new(file).lines();

    let trees: Vec<Vec<bool>> = lines
        .map(|l| l.unwrap().chars().map(|c| c == '#').collect())
        .collect();

    let width = trees[0].len();
    let height = trees.len();

    println!("Map dimensions {} x {}", width, height);

    let slopes = vec![(1, 1), (3, 1), (5, 1), (7, 1), (1, 2)];

    let mut overall = 1u32;

    for (x_step, y_step) in slopes.iter() {
        let mut x = 0;
        let mut y = 0;
        let mut count = 0;

        while y < height {
            if trees[y][x % width] {
                count += 1
            }
            x += x_step;
            y += y_step;
        }

        println!("Count for {} {} : {}", x_step, y_step, count);
        overall *= count;
    }

    println!("Final result: {}", overall);

    Ok(())
}