gmpRandEx.c

/**
   @file      gmpRandEx.c
   @author    Mitch Richling <http://www.mitchr.me/>
   @Copyright Copyright 1999 by Mitch Richling.  All rights reserved.
   @brief     Example showing how to use the GMP random number generator.@EOL
   @Keywords  none
   @Std       C89

              The GMP contains a simple random number generator that
              is not suitable for simulation work, but is good enough
              for things like checking arithmetic algorithms and the
              like.
*/

#include <stdlib.h>             /* Standard Lib    ISOC  */
#include <stdio.h>              /* I/O lib         ISOC  */
#include <stdarg.h>             /* Variable args   ISOC  */
#include <gmp.h>                /* GNU GMP Library       */

int main (void) {
  int             i;            /* Loop variable */
  mpz_t           randNum;      /* Hold our random numbers */
  int             rndBit;       /* Bound for mpz_urandomb */
  mpz_t           rndBnd;       /* Bound for mpz_urandomm */
  gmp_randstate_t gmpRandState; /* Random generator state object */

  /* Initialize randNum before we use it. */
  mpz_init(randNum);

  /* Initialize Bounds */
  rndBit = 18;
  mpz_init_set_str(rndBnd, "1000", 10);

  /* Initialize the random state with default algorithm... */
  gmp_randinit_default(gmpRandState);

  /* Seed the state with an unsigned long int before we begin.. */
  /* One can set the seed from an mpz_t too with gmp_randseed() */
  gmp_randseed_ui(gmpRandState, 1234567890);

  printf("10 random numbers in U[0, -1+2**%d]:\n", rndBit);
  for(i=0; i<10; i++) {
    /* mpz_get_ui() can convert randNum to unsigned long int... */
    mpz_urandomb(randNum, gmpRandState, rndBit);
    mpz_out_str(stdout, 10, randNum);
    printf("\n");
  } /* end for */

  printf("10 random numbers in U[0, ");
  mpz_out_str(stdout, 10, rndBnd);
  printf("]:\n");
  for(i=0; i<10; i++) {
    /* mpz_get_ui() can convert randNum to unsigned long int... */
    mpz_urandomm(randNum, gmpRandState, rndBnd);
    mpz_out_str(stdout, 10, randNum);
    printf("\n");
  } /* end for */

  /* Clean up resources occupied by compensated */
  gmp_randclear(gmpRandState);

  /* Clean up resources occupied by our mpz_t variables */
  mpz_clear(randNum);
  mpz_clear(rndBnd);
  return 0;
} /* end func main */