use std::io::{self, BufRead};
use std::path::Path;
use std::fs::File;

fn main(){
    println!("Advent of Code #1!");
    println!();

    let path = Path::new("./1.txt");
    let display = path.display();

    let file = match File::open(&path) {
        Err(why) => panic!("Couldn't open {}: {}", display, why),
        Ok(file) => file,
    };

    let lines = io::BufReader::new(file).lines();
    let mut n = 0;
    let mut prev = 0;
    let mut line_vec = Vec::new();

    for line in lines {
        if let Ok(l) = line{
            let i: u32 = l.parse().unwrap();
            if i > prev {
                n += 1;
            }
            prev = i;
            line_vec.push(i);
        }
    }

    println!("Number of increases: {}", n - 1);
    println!();

    prev = 0;
    n = 0;

    for i in 0..(line_vec.len() - 2) {
        let sum = line_vec[i] + line_vec[i+1] + line_vec[i+2];
        if sum > prev {
            n += 1;
        }
        prev = sum;
    }

    println!("Number of increases with shifting window: {}", n - 1);
}