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/day1.txt")?;
    let lines = io::BufReader::new(file).lines().map(|l| l.unwrap());

    let numbers: Vec<u64> = lines.map(|l| l.parse().unwrap()).collect();

    let mut last_number: Option<u64> = None;
    let mut count = 0;
    for num in numbers.iter() {
        if let Some(last_number) = last_number {
            if num > &last_number {
                count += 1;
            }
        }
        last_number = Some(*num);
    }

    println!("Answer Part1: {}", count);

    count = 0;
    last_number = None;
    for window in numbers.windows(3) {
        let num = window.iter().fold(0, |a, b| a + b);
        if let Some(last_number) = last_number {
            if num > last_number {
                count += 1;
            }
        }
        last_number = Some(num);
    }

    println!("Answer Part2: {}", count);

    Ok(())
}