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

fn main() {
	let mut sum = 0;
	let mut mus = 0;

	if let Ok(lines) = read_lines("./input") {
		for line in lines {
			if let Ok(text) = line {
				//println!(
				//	"{} yields {:?} + {:?}",
				//	text,
				//	first_digit(&text),
				//	last_digit(&text),
				//);
				sum = sum + first_digit(&text).unwrap_or(0);
				mus = mus + last_digit(&text).unwrap_or(0);
			} else {
				println!("Error on line \"{:?}\"", line);
			}
		}
	}

	println!("{}", 10*sum + mus);
}

const DIGITSTABLE: [(&str, u32); 18]= [
	("1", 1), ("one",   1),
	("2", 2), ("two",   2),
	("3", 3), ("three", 3),
	("4", 4), ("four",  4),
	("5", 5), ("five",  5),
	("6", 6), ("six",   6),
	("7", 7), ("seven", 7),
	("8", 8), ("eight", 8),
	("9", 9), ("nine",  9),
];

fn first_digit(text: &String) -> Option<u32> {
	let digits = HashMap::from(DIGITSTABLE);

	let mut hit = false;
	let mut first_digit: &u32 = &0;
	let mut first_index: usize = 0;
	for (needle, digit) in &digits {
		let index = text.find(needle);
		if index.is_some() && (!hit || index.unwrap() < first_index) {
			hit = true;
			first_digit = digit;
			first_index = index.unwrap();
		}
	}
	if hit { Some(*first_digit) } else { None }
}

fn last_digit(text: &String) -> Option<u32> {
	let digits = HashMap::from(DIGITSTABLE);

	let mut hit = false;
	let mut last_digit: &u32 = &0;
	let mut last_index: usize = 0;
	for (needle, digit) in &digits {
		let index = text.rfind(needle);
		if index.is_some() && (!hit || index.unwrap() > last_index) {
			hit = true;
			last_digit = digit;
			last_index = index.unwrap();
		}
	}
	if hit { Some(*last_digit) } else { None }
}

fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
where P: AsRef<Path>, {
    let file = File::open(filename)?;
    Ok(io::BufReader::new(file).lines())
}