On Fri, Jan 14, 2005 at 10:17:27AM +0100, Ketil Malde wrote: > Tomasz Zielonka <[EMAIL PROTECTED]> writes: > > > On Fri, Jan 14, 2005 at 09:17:41AM +0100, Gracjan Polak wrote: > >> This algorithm seems not effective, length, take, drop and (!!) are > >> costly. Is there any better way to implement shuffle? > > > You can use mutable arrays (modules Data.Array.MArray, Data.Array.IO). > > But is that better, really? IIUC, you will now need to shift the first > part of the string to the right, so it's still a linear operation for > each shuffle.
Perhaps I don't know this particular algorithm, but you can shuffle the array with linear number of swaps. No need to shift elements. Best regards, Tomasz _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
