Created
March 3, 2017 16:14
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Haskell permutation generation algorithm with list comprehension.
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| import Data.List | |
| perm :: (Eq a) => [a] -> Int -> [[a]] | |
| perm _ 0 = [[]] | |
| perm xs r | length xs < r = [[]] | |
| | otherwise = [x:ys | x <- xs, ys <- perm (delete x xs) (r - 1)] |
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Hi, @readamd256,
To be honest, I forgot how I came up with this code snippets. But I think this gist is just a step of generalisation of your code.