use md5::{Digest, Md5};
use std::{
    collections::HashMap,
    fs::File,
    io::{BufWriter, Write},
};

fn main() -> std::io::Result<()> {
    let mut map = HashMap::new();
    for i in 0u32..=std::u32::MAX {
        let mut hasher = Md5::new();
        hasher.update(i.to_le_bytes());
        let out = hasher.finalize();
        let key = out[out.len() - 1];
        *map.entry(key).or_insert(0) += 1;
        if i % 100_000 == 0 {
            println!("{i}");
        }
    }
    let mut count_list = map.into_iter().collect::<Vec<_>>();
    count_list.sort();
    let file = File::create("./countmap.txt")?;
    let mut writer = BufWriter::new(file);
    for (k, v) in count_list {
        writeln!(writer, "{:02x}: {}", k, v)?;
    }
    Ok(())
}