andersk · August 29, 2015 14:21
diff --git a/flowsnake.hs b/flowsnake.hs
 -- http://codegolf.stackexchange.com/questions/50521/ascii-art-of-the-day-2-flow-snakes

 import Control.Applicative  -- not needed in GHC 7.10

 (?)=div
 (%)=mod
 t[a,b]=[3*a+b,2*b-a]
 _#[0,0]=0
 0#_=3
 n#p=[352,6497,2466,-1]!!((n-1)#t[(s+3)?7|s<-p])?(4^p!!0%7)%4
 0&_=0
 n&p=(n-1)&t p+maximum(abs<$>sum p:p)
 n!b=n&[1,-b]
 f n=putStr$unlines[["__ \\/   "!!(2*n#t[a?2,-b]+a%2)|a<-[b-n!2+1..b+n!2+0^n?3]]|b<-[-n!0..n!0]]

 main=f 3
	-- http://codegolf.stackexchange.com/questions/50521/ascii-art-of-the-day-2-flow-snakes

	import Control.Applicative -- not needed in GHC 7.10

	(?)=div
	(%)=mod
	t[a,b]=[3a+b,2b-a]
	_#[0,0]=0
	0#_=3
	n#p=[352,6497,2466,-1]!!((n-1)#t[(s+3)?7\|s<-p])?(4^p!!0%7)%4
	0&_=0
	n&p=(n-1)&t p+maximum(abs<$>sum p:p)
	n!b=n&[1,-b]
	f n=putStr$unlines[["__ \\/ "!!(2*n#t[a?2,-b]+a%2)\|a<-[b-n!2+1..b+n!2+0^n?3]]\|b<-[-n!0..n!0]]

	main=f 3