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advent-of-code/2020/04/part2.hs
2022-09-21 09:19:52 -04:00

62 lines
1.7 KiB
Haskell
Executable file

#!/usr/bin/env runghc
-- byr (Birth Year)
-- iyr (Issue Year)
-- eyr (Expiration Year)
-- hgt (Height)
-- hcl (Hair Color)
-- ecl (Eye Color)
-- pid (Passport ID)
-- cid (Country ID)
import Data.Char
import Data.Map.Strict (fromList, member)
isValidEntry ("byr", byr)
| byr >= "1920" && byr <= "2002" = True
| otherwise = False
isValidEntry ("iyr", iyr)
| iyr >= "2010" && iyr <= "2020" = True
| otherwise = False
isValidEntry ("eyr", eyr)
| eyr >= "2020" && eyr <= "2030" = True
| otherwise = False
isValidEntry ("hgt", hgt@(a:b:c:"cm")) = hgt >= "150cm" && hgt <= "193cm"
isValidEntry ("hgt", hgt@(a:b:"in")) = hgt >= "59in" && hgt <= "76in"
isValidEntry ("hcl", '#':hcl) = length hcl == 6 && all isHexDigit hcl
isValidEntry ("ecl", "amb") = True
isValidEntry ("ecl", "blu") = True
isValidEntry ("ecl", "brn") = True
isValidEntry ("ecl", "gry") = True
isValidEntry ("ecl", "grn") = True
isValidEntry ("ecl", "hzl") = True
isValidEntry ("ecl", "oth") = True
isValidEntry ("pid", pid) = length pid == 9 && all isDigit pid
isValidEntry ("cid", _) = True -- ignored
isValidEntry _ = False
toEntry = fmap tail . break (==':')
main = interact (solve . getMaps)
solve = show . length . filter isValidDocument
isValidDocument document =
member "byr" document &&
member "iyr" document &&
member "eyr" document &&
member "hgt" document &&
member "hcl" document &&
member "ecl" document &&
member "pid" document
getMaps = map (fromList . filter isValidEntry . map toEntry . words) . joinLines . lines
joinLines = foldl parse [""]
where
parse [""] l = [l]
parse [a] "" = ["", a]
parse [a] l = [l ++ " " ++ a]
parse (a:as) l = parse [a] l ++ as