aoc 2022 day06

day06.rs

use std::collections::HashSet;

fn main() {
    let input = include_str!("day06_input.txt");
    let data: Vec<char> = input.chars().collect();

    // just let HashSet do all the work
    let mut message_set = HashSet::new();
    for i in 0..data.len() {
        if i >= 13 {
            message_set.clear();
            for j in i - 13..=i {
                message_set.insert(data[j]);
            }
            if message_set.len() == 14 {
                eprintln!("start-of-message marker at {}", i + 1);
                break;
            }
        }
    }
}