use std::env;
use std::fs;
use std::process;
//use std::{thread, time};

fn main() {
    //println!("Hello world!");

    let args: Vec<String> = env::args().collect();
    let path: String;

    if args.len() > 1 {
         path = args[1].clone();
    } else {
        println!("Specify an input file!");
        process::exit(1);
    }

    if ! fs::metadata(path.clone()).is_ok() {
        println!("Path does not exist!");
        process::exit(1);
    }

    //let rawInput = fs::read_to_string(path.clone()).unwrap();
    //let splitInput: Vec<&str> = rawInput.lines().collect();

    let mut left: Vec<i32> = vec![];
    let mut right: Vec<i32> = vec![];

    for line in fs::read_to_string(path.clone()).unwrap().lines() {
        //let line = splitInput[i];
        let split: Vec<&str> = line.split("   ").collect();

        //println!("{}",split[0]);

        left.push(split[0].parse().unwrap());
        right.push(split[1].parse().unwrap());
    }

    left.sort();
    //left.dedup();

    right.sort();
    //right.dedup();

    let mut accum: i32 = 0;
    for i in 0..right.len() {
        //println!("{}, {}", left[i], right[i]);
        //println!("Distance is {}", (right[i] - left[i]).abs());
        accum += (right[i] - left[i]).abs();

        //thread::sleep(time::Duration::from_millis(1000));
    }

    println!("Answer: {}", accum);
}