c++ and haskell Quick short

main.cpp

void quickSort(int arr[], int start, int end)
{
    if (start >= end) return;
    int p = partition(arr, start, end);
    quickSort(arr, start, p - 1);
    quickSort(arr, p + 1, end);
}

main.hs

    quicksort :: (Ord a) => [a] -> [a]    
    quicksort [] = []    
    quicksort (x:xs) =     
        let smallerSorted = quicksort (filter (<=x) xs)  
            biggerSorted = quicksort (filter (>x) xs)   
        in  smallerSorted ++ [x] ++ biggerSorted