9/one.icl

   1 module one
   2
   3 import StdEnv
   4 import Data.List
   5 import Data.Func
   6 import StdMaybe
   7
   8 read :: *File -> [Int]
   9 read f
  10         # (ok, i, f) = freadi f
  11         | not ok = []
  12         = [i:read f]
  13
  14 Start w
  15         # (io, w) = stdio w
  16         # ls = read io
  17         = (one ls, two ls)
  18
  19 one = last o pre
  20
  21 pre l
  22         # (preamble, [num:rest]) = splitAt 25 l
  23         | isEmpty [()\\(x, y)<-diag2 preamble preamble | x+y==num] = [num]
  24         = [num:pre (tl l)]
  25
  26 two ls
  27         # ls = fst (splitAt 25 ls) ++ pre ls
  28         = let a = calc (last ls) ls in last a + hd a
  29 where
  30         calc num = sort o hd o hd o filter (not o isEmpty) o map (filter ((==)num o sum) o dropWhile ((<)num o sum) o inits) o tails