On 2004-12-16 at 17:00+0100 Henning Thielemann wrote: > > > imranazad wrote: > > > Hi, > > > > > > im not very good with haskell, i barely know the > > > basics, my coursework requires me to genereate a > > > vigenere square....... well anyway at the moment im > > > trying to define a functin all_rotations which for any > > > list returns the list of all its rotations, so far > > > i've made an attempt but it only rotates once....any > > > ideas? i dont want the complete solution just help > > > thats all, much appreciated. > > > > > > all_rotations :: [a] -> [[a]] > > > all_rotations [] = [] > > > all_rotations (x:xs) = reverse (x:xs) : [] > > 'cycle' the list, then determine all of its suffixes with > 'tails' and take the first elements of each list.
playing with inits l `zip` tails l might also be edifying. -- J�n Fairbairn [EMAIL PROTECTED] _______________________________________________ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
