99 questions/Solutions/15

From HaskellWiki
< 99 questions‎ | Solutions
Revision as of 14:21, 5 August 2011 by Sekol (talk | contribs) (added solution using list monad)

Jump to: navigation, search

(**) Replicate the elements of a list a given number of times.

repli :: [a] -> Int -> [a]
repli xs n = concatMap (replicate n) xs

or, in Pointfree style:

repli = flip $ concatMap . replicate

alternatively, without using the replicate function:

repli :: [a] -> Int -> [a]
repli xs n = concatMap (take n . repeat) xs

or, using the list monad:

repli :: [a] -> Int -> [a]
repli xs n = xs >>= replicate n