H-99: Ninety-Nine Haskell Problems

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These are Haskell translations of Ninety Nine Lisp Problems.

Problem 1

(*) Find the last box of a list.
* (my-last '(a b c d))

This is "last" in Prelude, which is defined as:

last :: [a] -> a
last [x] = x
last (_:xs) = last xs

Problem 2

(*) Find the last but one box of a list.
* (my-but-last '(a b c d))
(C D)

This can be done by dropping all but the last two elements of a list:

myButLast :: [a] -> [a]
myButLast list = drop ((length list) - 2) list