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[aoc20.git] / 12 / one.icl

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+module one
+
+import StdEnv
+import Data.Func
+import Data.Tuple
+
+read :: *File -> [(Char, Int)]
+read f
+       # (l, f) = freadline f
+       | l.[size l - 1] <> '\n' = []
+       = [(l.[0], toInt (l % (1, size l - 2))):read f]
+
+Start w
+       # (io, w) = stdio w
+       # ls = read io
+       = (\s->abs s.x+abs s.y) $ foldl move {x=0,y=0,dirs=dirs} ls
+
+dirs = [(1, 0),(0,-1),(-1,0),(0,1):dirs]
+
+:: Ship = {x :: Int, y :: Int, dirs :: [(Int, Int)]}
+
+move s ('N', n) = {s & y=s.y+n}
+move s ('S', n) = {s & y=s.y-n}
+move s ('E', n) = {s & x=s.x+n}
+move s ('W', n) = {s & x=s.x-n}
+move s=:{dirs=[(dx, dy):_]} ('F', n) = {s & x=s.x+dx*n, y=s.y+dy*n}
+move s ('R', n) = {s & dirs=drop (n/90) s.dirs}
+move s ('L', n) = {s & dirs=drop (3*(n/90)) s.dirs}