selectionsort.hs

import Data.List
import Data.Maybe

selectionsort [] = []
selectionsort xs = head swapped : (selectionsort $ tail swapped)
    where swapped = swap 0 indexOfMin xs
          indexOfMin = fromJust $ elemIndex (minimum xs) xs

-- リスト xs のインデックス i, j の要素を交換
swap i j xs | i < j  = slice 0 (i-1) xs     ++ [xs!!j] ++ 
                       slice (i+1) (j-1) xs ++ [xs!!i] ++
                       slice (j+1) ((length xs)-1) xs
            | i == j = xs

-- リスト xs のインデックス i から j の間の要素を取得
slice i j xs | i < j  = xs!!i : slice (i+1) (j-1) xs ++ [xs!!j]
             | i == j = [xs!!i]
             | i > j  = []