99 questions/Solutions/2: Difference between revisions
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myButLast''' (x:(_:[])) = x | myButLast''' (x:(_:[])) = x | ||
myButLast''' (_:xs) = myButLast''' xs | myButLast''' (_:xs) = myButLast''' xs | ||
myButLast'''' = head . tail . reverse | |||
</haskell> | </haskell> | ||
Revision as of 14:38, 25 October 2011
(*) 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