Re: [Haskell-cafe] Re: Function to detect duplicates

Ertugrul: while your solution is minimalistic, Rafael deemed his ~n*log n implementation too inefficient. Thus your ~n^3 implementation is hardly an improvement... /Jonas On 23 February 2010 13:03, Ertugrul Soeylemez wrote:

Rafael Gustavo da Cunha Pereira Pinto wrote:

...

While solving a puzzle, I was posed the problem of finding if there was no duplicates on a list.

First I used:

noneRepeated=null.(filter (>1)).(map length).group.sort

But this seemed very unneficient, so I thought that I could detect the duplicates while sorting, and devised this:

import Control.Monad import Data.Maybe

noneRepeated=isNothing . (foldl merge (Just [])) . (map sort) . pairs

import Data.List

noneRepeated xs = xs == nub xs

Greets Ertugrul

-- nightmare = unsafePerformIO (getWrongWife >>= sex) http://blog.ertes.de/

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