Regex only solution for Advent of Code 2022, Day 6

aoc_2022_06_regex.rb

input = 'mjqjpqmgbljsphdztnvjfqwrcgsmlb'

# Part 1
input.match(/(.)(?!\1)(.)(?!\1|\2)(.)(?!\1|\2|\3)./).end 0 # => 7

# Part 2
input.match(
  %r{
    (.)(?!.{,12}\1)
    (.)(?!.{,11}\2)
    (.)(?!.{,10}\3)
    (.)(?!.{,9}\4)
    (.)(?!.{,8}\5)
    (.)(?!.{,7}\6)
    (.)(?!.{,6}\7)
    (.)(?!.{,5}\8)
    (.)(?!.{,4}\9)
    (.)(?!.{,3}\10)
    (.)(?!.{,2}\11)
    (.)(?!.?\12)
    (.)(?!\13)
    .
  }x
).end 0 # => 19