52 lines
1.7 KiB
Elixir
52 lines
1.7 KiB
Elixir
defmodule DayFive do
|
|
def part_one(input) do
|
|
shortened = fully_react_new(input)
|
|
# IO.puts shortened
|
|
(String.length shortened) - 1
|
|
end
|
|
|
|
def fully_react(input) do
|
|
replacer = ~r/Aa|Bb|Cc|Dd|Ee|Ff|Gg|Hh|Ii|Jj|Kk|Ll|Mm|Nn|Oo|Pp|Qq|Rr|Ss|Tt|Uu|Ww|Vv|Xx|Yy|Zz|aA|bB|cC|dD|eE|fF|gG|hH|iI|jJ|kK|lL|mM|nN|oO|pP|qQ|rR|sS|tT|uU|wW|vV|xX|yY|zZ/
|
|
replace_forever(input, replacer, "")
|
|
end
|
|
|
|
|
|
def replace_forever(string, pattern, replacement) do
|
|
if Regex.match?(pattern, string) do
|
|
replace_forever(Regex.replace(pattern, string, replacement), pattern, replacement)
|
|
else
|
|
string
|
|
end
|
|
end
|
|
|
|
def react([<< char1 >> , << char2 >> | tail]) when char1 == char2 - 32 or char2 == char1 - 32, do: react(tail)
|
|
def react([char | tail]), do: [char | react(tail)]
|
|
def react(""), do: []
|
|
def react([]), do: []
|
|
|
|
def fully_react_new(input) do
|
|
# IO.puts "mark"
|
|
Enum.join( fully_react_new(String.codepoints(input), []) )
|
|
end
|
|
|
|
def fully_react_new(input, acc) when input == acc, do: acc
|
|
def fully_react_new(input, _acc) do
|
|
# IO.puts("#{length _acc} #{length input}")
|
|
fully_react_new(react(input), input)
|
|
end
|
|
|
|
def part_two(input) do
|
|
chars = Enum.map(?a..?z, &(<< &1 >>))
|
|
[{_char, poly} | _ ] = Enum.map(chars, fn char -> {char, String.replace(input, char, "")} end)
|
|
|> Enum.map(fn {char, poly} -> {char, String.replace(poly, String.upcase(char), "") } end)
|
|
|> Enum.map(fn {char, poly} -> {char, fully_react_new(poly)} end)
|
|
|> Enum.sort_by(fn {_char, poly} -> String.length(poly) end)
|
|
# IO.puts poly
|
|
String.length(poly) - 1
|
|
end
|
|
end
|
|
|
|
{:ok, content} = File.read "input5.txt"
|
|
|
|
IO.puts "Part 1: #{DayFive.part_one(content)}"
|
|
IO.puts "Part 2: #{DayFive.part_two(content)}"
|