Function aoc::y15d05::y15d05

pub fn y15d05(input: &str, part: u32) -> u32

The solution for the day five challenge.

We expect the input as a string and either part 1 or part 2 to decide which ruleset to use to determine “nice” strings.

In part one nice strings contain at least three vowels (aeiou only), contains at least one letter that appears twice in a row, and does not contain any of these substrings: ab, cd, pq, or xy. The final rule takes precedence over the first two, that is if a string meets the first two criteria but has one of the forbidden substrings then it is still naughty.

In part two the rules are slightly different. A nice string contains at least one pair of non-overlapping (in position in the string) characters and at least one character that repeats after one other character.

Example

// probably read this from the input file...
let input = "abc\naeidd\nxxxxyx";
assert_eq!(y15d05(input, 1), 1);
assert_eq!(y15d05(input, 2), 1);