use rand::Rng;
use std::time::Instant;

type Ticket = [u8; 5];
const NUM_ENTRIES: usize = 10_000_000;

// println!("char: {}", rand::random::<char>());

fn gen_num() -> u8 {
    rand::thread_rng().gen_range(0..90)
}

fn gen_ticket() -> Ticket {
    let num1 = gen_num();
    let mut num2: u8 = gen_num();
    while num2 == num1 {
        num2 = gen_num()
    }
    let mut num3: u8 = gen_num();
    while num3 == num1 || num3 == num2 {
        num3 = gen_num()
    }
    let mut num4: u8 = gen_num();
    while num4 == num1 || num4 == num2 || num4 == num3 {
        num4 = gen_num()
    }
    let mut num5: u8 = gen_num();
    while num5 == num1 || num5 == num2 || num5 == num3 || num5 == num4 {
        num5 = gen_num()
    }
    [num1, num2, num3, num4, num5]
}

fn num_matches(t1: Ticket, t2: Ticket) -> usize {
    let mut result = 0;
    for n1 in t1 {
        for n2 in t2 {
            if n1 == n2 {
                result += 1;
            }
        }
    }
    result
}

fn main() {
    println!("Generating entries");
    let mut entries: Vec<Ticket> = Vec::with_capacity(NUM_ENTRIES);
    for _ in 0..NUM_ENTRIES {
        entries.push(gen_ticket());
    }
    let winning = gen_ticket();

    let start = Instant::now();

    println!("Counting winners...");
    let mut winners: [usize; 6] = [0, 0, 0, 0, 0, 0];

    for n in entries {
        let num_winning = num_matches(n, winning);
        winners[num_winning] += 1
    }

    let duration = start.elapsed();

    println!(
        "Winners: {:?}\nTime Elapsed: {}ms",
        winners,
        duration.subsec_millis()
    );
}