Day 05

Mix.install([
  {:kino, "~> 0.14.2"}
])

IEx.Helpers.c("/Users/johnb/dev/2015adventOfCode/advent_of_code.ex")
alias AdventOfCode, as: AOC
alias Kino.Input
require Integer

# Note: when making the next template, something like this works well:
#   `cat day01.livemd | sed 's/01/02/' > day02.livemd`
#

Installation and Data

input_p1example = Kino.Input.textarea("Example Data")

input_p1puzzleInput = Kino.Input.textarea("Puzzle Input")

input_source_select =
  Kino.Input.select("Source", [{:example, "example"}, {:puzzle_input, "puzzle input"}])

p1data = fn ->
  (Kino.Input.read(input_source_select) == :example &&
     Kino.Input.read(input_p1example)) ||
    Kino.Input.read(input_p1puzzleInput)
end

Solution

defmodule Day05 do
  @vowels ~r/a|e|i|o|u/
  @doubles ~r/aa|bb|cc|dd|ee|ff|gg|hh|ii|jj|kk|ll|mm|nn|oo|pp|qq|rr|ss|tt|uu|vv|ww|xx|yy|zz/
  @bad_pairs ~r/ab|cd|pq|xy/

  def bad_line?(line) do
    vowel_count = Regex.scan(@vowels, line) |> Enum.count()
    cond do
      line =~ @bad_pairs -> true
      vowel_count < 3 -> true
      true -> not (line =~ @doubles)
    end
  end
  
  def solve1(text) do
    text
    |> AOC.as_single_lines()
    |> Enum.reduce(0, fn line, acc ->
      if bad_line?(line) do
        IO.puts("bad:  #{line}")
        acc
      else
        IO.puts("good: #{line}")
        acc + 1
      end
    end)
  end

  def bad_line2?(line) do
    separated_dupes? = Regex.match?(~r/(.).(\1)/, line)
    separated_pairs? = Regex.match?(~r/(..).*(\1)/, line)

    !separated_dupes? || !separated_pairs?
  end

  def solve2(text) do
    text
    |> AOC.as_single_lines()
    |> Enum.reduce(0, fn line, acc ->
      if bad_line2?(line) do
        IO.puts("bad:  #{line}")
        acc
      else
        IO.puts("good: #{line}")
        acc + 1
      end
    end)
  end
end

# Example data:
# ugknbfddgicrmopn
# aaa
# jchzalrnumimnmhp
# haegwjzuvuyypxyu
# dvszwmarrgswjxmb
# qjhvhtzxzqqjkmpb
# xxyxx
# uurcxstgmygtbstg
# ieodomkazucvgmuy

p1data.()
|> Day05.solve1()
|> IO.inspect(label: "\n*** Part 1 solution (example: 2)")
# 258

p1data.()
|> Day05.solve2()
|> IO.inspect(label: "\n*** Part 2 solution (example: 2)")
# 53