3/one.icl

   1 module one
   2
   3 import StdEnv
   4
   5 read :: *File -> [[Int]]
   6 read f
   7         # (l, f) = freadline f
   8         | l.[size l - 1] <> '\n' = []
   9         = [let c = [if (c == '#') 1 0\\c<-:l | c <> '\n'] ++ c in c:read f]
  10
  11 Start w
  12         # (io, w) = stdio w
  13         # ls = read io
  14         = (one ls, two ls)
  15
  16 one ls :== slope ls (3, 1)
  17
  18 two :: [[Int]] -> Int
  19 two ls = prod (map (slope ls) [(1,1), (3,1), (5,1), (7,1), (1,2)])
  20
  21 slope :: [[Int]] (Int, Int) -> Int
  22 slope [] _ = 0
  23 slope xs=:[[c:_]:_] d=:(right, down) = c + slope (map (drop right) (drop down xs)) d