Re: Permutation and Combination how to find rank?

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Wed, Jul 09, 2014 at 04:22:54PM +0530, chandra sekaran wrote:
> Sorry.
> 
> My question is wrong. It will have multiple solutions.
> 
> Digits function is O.K
> 
> (16:20) gp > digits(256^3-1,256)
> %554 = [255, 255, 255]
> 
> Is there any reverse function is available ( By giving vector [255, 255,
> 255]  i will get 256^3-1.

You can use
subst(Polrev([255, 255, 255]),x,256)

But we should probably add a function fromdigits() or digitsback().
(Especially since I implemented gen_fromdigits() in libpari)

Cheers,
Bill.