use std::time::{Duration, Instant};

const END: usize = 30_000_000;
pub fn run(print: bool) -> Duration {
    let input: Vec<usize> = "0,1,5,10,3,12,19"
        .split(",")
        .map(|i| i.parse().unwrap())
        .collect();
    let instant = Instant::now();

    let mut history = vec![0; END];
    let mut last = input[0];
    for turn in 0..input.len() {
        history[last] = turn;
        last = input[turn];
    }

    for turn in input.len()..2020 {
        let stored = history[last];
        history[last] = turn;
        last = if stored == 0 { 0 } else { turn - stored };
    }
    if print {
        println!("Part 1: {}", last);
    }

    for turn in 2020..END {
        let stored = history[last];
        history[last] = turn;
        last = if stored == 0 { 0 } else { turn - stored };
    }
    if print {
        println!("Part 2: {}", last);
    }

    instant.elapsed()
}