Discussion on: Advent of Code 2019 Solution Megathread - Day 4: Secure Container

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The first part was pretty easy and in the second part I was trying to construct a perfect regex initially so that didn't work out. One thing that stumped me a bit was that in rust string.split("") throws a "" at the beginning and the end.

I haven't completed Day 3 yet, gonna do that later. I figured out the logic for Day 3 but there's some problem with the implementation.

I've uploaded all my Advent of Code 2019 solutions in rust on a github repo : github.com/coolshaurya/advent_of_c...

Day 3 solution using Rust

extern crate regex;

#[macro_use]
extern crate lazy_static;

use regex::Regex;
use std::collections::HashMap;

lazy_static! {
    static ref RE1: Regex = Regex::new(r"11|22|33|44|55|66|77|88|99|00").unwrap();
}

fn process_input(raw: String) -> Vec<u32> {
    raw.split("-")
        .map(|val| val.parse::<u32>().unwrap())
        .collect::<Vec<u32>>()
}

fn is_valid_a(password: String) -> bool {
    RE1.is_match(&password) && password.split("").filter(|val| val.len() > 0).is_sorted()
}

fn is_valid_b(password: String) -> bool {
    let correct_digit_order: bool = password.split("").filter(|val| val.len() > 0).is_sorted();
    let mut  only_two_grouping: bool = false;
    let mut digit_frequency = HashMap::new();

    for digit in password.split("").filter(|val| val.len() > 0) {
        let count = digit_frequency.entry(digit).or_insert(0);
        *count += 1
    }

    for digit in digit_frequency.keys() {
        if digit_frequency.get(digit).unwrap() == &2 {
            only_two_grouping = true;
            break;
        }
    }

    correct_digit_order && only_two_grouping
}

fn part_a(input: Vec<u32>) -> u32 {
    let mut valid_passwords: Vec<u32> = vec![];

    for passw in input[0]..input[1] {
        if is_valid_a(passw.to_string()) {
            valid_passwords.push(passw);
        }
    }

    valid_passwords.len() as u32
}

fn part_b(input: Vec<u32>) -> u32 {
    let mut valid_passwords: Vec<u32> = vec![];

    for passw in input[0]..input[1] {
        if is_valid_b(passw.to_string()) {
            valid_passwords.push(passw);
        }
    }

    valid_passwords.len() as u32
}