I just realized that it doesn't work properly with a longer list length than 3, back to the drawing board.
/Henrik On Thu, Dec 25, 2008 at 7:41 PM, Henrik Sarvell <hsarv...@gmail.com> wrote: > Hello everyone, I couldn't find anything already created to this > effect so I sat down and did this, I even wrote a little about it > here: > http://www.prodevtips.com/2008/12/25/factorials-permutations-and-recursion-in-pico-lisp/ > > (de fac (Num) > > (let Res 1 > > (for (N 1 (>= Num N) (inc N)) > > (setq Res (* Res N))))) > > > > (de switch (Lst P1 P2) > > (let (V1 (get Lst P1) V2 (get Lst P2)) > > (place P1 (place P2 Lst V1) V2))) > > > > (de permutate (Lst) > > (let (Result (list) Count 1 Start 1) > > (recur (Lst Start Result Count) > > (when (>= (fac (length Lst)) Count) > > (push Result Lst) > > (when (= Start (length Lst)) (setq Start 1)) > > (recurse > > (switch Lst Start (inc Start)) > > (inc Start) > > Result > > (inc Count))) > > (car Result)))) > > > > (permutate '(1 2 3)) > > I'm sure this could be done more efficiently and with less code, > anyone has any suggestions? > > Anyway when this stuff - and I'm sure there is more like it - has been > sanitized/optimized maybe it could constitute some kind of extended > library, lib2.l maybe? > > Cheers and happy new year! > > /Henrik > -- UNSUBSCRIBE: mailto:picol...@software-lab.de?subject=unsubscribe