Difference between revisions of "99 questions/Solutions/2"

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Line 14: Line 14:
   
 
myButLast'''' = head . tail . reverse
 
myButLast'''' = head . tail . reverse
  +
  +
myButLast''''' = head . drop 1 . reverse
 
</haskell>
 
</haskell>

Revision as of 16:37, 31 May 2012

(*) 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''''' = head . drop 1 . reverse