Day: December 29, 2015

https://en.wikipedia.org/wiki/Tower_of_Hanoi

hanoi :: Integer -> String -> String -> String -> [(String, String)]
hanoi 0 _ _ _ = []
hanoi n a b c = hanoi (n-1) a c b ++ [(a, b)] ++ hanoi (n-1) c b a

hanoiIO n = mapM_ f $ hanoi n "Pole 1" "Pole 3" "Pole 2" where
  f (x,y) = putStrLn $ "Move from " ++ show x ++ " to " ++ show y

main = do
  hanoiIO 3

Move from "Pole 1" to "Pole 3"
Move from "Pole 1" to "Pole 2"
Move from "Pole 3" to "Pole 2"
Move from "Pole 1" to "Pole 3"
Move from "Pole 2" to "Pole 1"
Move from "Pole 2" to "Pole 3"
Move from "Pole 1" to "Pole 3"