99 questions/Solutions/2
< 99 questions | Solutions
(*) Find the last but one element of a list.
myButLast :: [a] -> a
myButLast = last . init
myButLast' x = reverse x !! 1
myButLast'' [x,_] = x
myButLast'' (_:xs) = myButLast'' xs
myButLast''' (x:(_:[])) = x
myButLast''' (_:xs) = myButLast''' xs
myButLast'''' = head . tail . reverse
myButLast''''' = snd.(foldl (\(a,b) c -> (c,a)) (e1, e2))
where e1 = error "List too small!"
e2 = error "List is null!"