use std::collections::HashMap;
use std::collections::HashSet;

#[path = "../lib.rs"]
mod lib;

fn step(x: u32) -> u32 {
    let mut y = x;
    y = y ^ ((y << 6) % (1 << 24));
    y = y ^ (y >> 5);
    y = y ^ ((y << 11) % (1 << 24));
    return y;
}

fn main() {
    let mut sum1 = 0;
    let mut sums2 = HashMap::new();

    for line in lib::iter_input() {
        let mut x = line.parse::<u32>().unwrap();
        let mut seen = HashSet::new();
        let mut pattern = 0;
        let mut prev = 0;

        for i in 0..2000 {
            x = step(x);
            let value = x % 10;
            let d = 10 + value - prev;  // +10 to avoid negative numbers
            pattern = ((pattern << 5) | d) % (1 << 20);
            if i >= 3 && seen.insert(pattern) {
                sums2
                    .entry(pattern)
                    .and_modify(|sum| *sum += value)
                    .or_insert(value);
            }
            prev = value;
        }
        sum1 += x as u64;
    }

    println!("part1: {}", sum1);
    println!("part2: {}", sums2.values().max().unwrap());
}