<html> <head> <style> .hmmessage P { margin:0px; padding:0px } body.hmmessage { FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } </style> </head> <body class='hmmessage'> Hi Rafael, This works to get the digits from an mpz_t variable. I did it with a char array but you could use pointers if you like.   #include <stdio.h> #include <math.h> #include <windows.h> #include <string.h> #include <stdlib.h> #include "gmp.h" #define getz(a) mpz_inp_str(a,stdin,10) int main(int argc, char * argv[]) { int i; char digit[2000]; char *tmp;   mpz_t num; printf("                     Get  mpz digits \n"); while(1) {   mpz_init(num); printf("num\n"); getz(num); mpz_get_str (digit,10,num); for(i=0;i<strlen(digit);i++) printf("%c",(int)digit[i]); printf("\n"); }   return 0; }   Input/Output:                      Get  mpz digits num 3141592653589793238462643383 3141592653589793238462643383 num   Cino Hilliard > Today's Topics: > > 1. Re: Addressing single digits of big integers (decio@decpp.net) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 25 Jul 2008 19:29:08 -0300 > From: "decio@decpp.net" <decio@decpp.net> > Subject: Re: Addressing single digits of big integers > To: "Rafael Anschau" <rafael.anschau@gmail.com>, gmp-discuss@swox.com > Message-ID: <488a53b4.94.2466.821384423@seti.serverlogistics.com> > Content-Type: text/plain; charset="iso-8859-1" > > > ----- Original Message ----- > From: "Rafael Anschau" <rafael.anschau@gmail.com> > To: gmp-discuss@swox.com > Subject: Addressing single digits of big integers > Date: Thu, 24 Jul 2008 16:48:03 -0300 > > > Is it possible to address single digits in big integers, > > without the high costs of export import ? Something like a > > pointer to the digit ? > > If by digit you mean a base-10 digit, sorry, it's gonna be > fairly costly. Most large integer packages represent values > internally in a power-of-two base, so you can't directly get > base-10 digits, only base-2^k digits. To get base-10 digits > you'll have to incur the cost of changing representation by > exporting, or doing a calculation like x/10^k mod 10, and > both the division and the modulo are costly for large > values. > > If you routinely need to work with the base-10 > representation of your large integers, and it's a bottleneck > of your code (profile it somewhere to be sure, otherwise you > may lose performance by following this advice), try a > different library which works with a power-of-10 base > representation. I can't name any, but I know that most of > the various Pi-calculator programs out there use base-10 > extensively to avoid a costly change of representation at > the end. > > D?cio > > > ------------------------------ > > _______________________________________________ > gmp-discuss mailing list > gmp-discuss@swox.com > https://gmplib.org/mailman/listinfo/gmp-discuss > > > End of gmp-discuss Digest, Vol 59, Issue 9 > ****************************************** </body> </html>