Karim Belabas on Fri, 12 Mar 2021 12:36:14 +0100 |
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Re: Time complexity of issquare() function |
* Karim Belabas [2021-03-12 12:34]: > * Donald Sitompul [2021-03-12 12:20]: > > What is the time complexity for the issquare() function? > > Assuming the input is an n-bit integer, the theoretical complexity is O(M(n)), > where M is the complexity of integer multiplication. > > In practice, the PARI and GMP kernel both implement Schönhage / Strassen > and M(n) is O(n log(n) loglog(n)). I forgot a small detail: the native PARI kernel does not implement fast division. So the complexity without the GMP kernel is O(n^2). Cheers, K.B. -- Karim Belabas, IMB (UMR 5251) Tel: (+33) (0)5 40 00 26 17 Universite de Bordeaux Fax: (+33) (0)5 40 00 21 23 351, cours de la Liberation http://www.math.u-bordeaux.fr/~kbelabas/ F-33405 Talence (France) http://pari.math.u-bordeaux.fr/ [PARI/GP] `