factorizante_v0.51.c

/* (c) 2017 - Nuno Ferreira
 * This program is licensed under the GNU GPLv3 or later */
/* gcc factorizante_v0.30.c -o Factorizante -lgmp */

#include <gmp.h>
#include <stdio.h>
#include <time.h>

int main(int argc, char ** argv)
{
  clock_t begin = clock();	/*Start timer */
  mpz_t prime_number, number_to_factorize, count;
  int is_divisible;
  mpz_init_set_ui(prime_number,2); /* initialize prime_number */
  mpz_init_set_ui(count,0); /* initialize count */
  mpz_init_set_str (number_to_factorize, argv[1], 10); /* inset here the number you want to factorize */

  while (1 > 0)
  {
    if (mpz_probab_prime_p(number_to_factorize , 40) != 0)  /* check if number_to_factorize is a prime */
	  {
	    mpz_out_str(stdout,10,number_to_factorize); /* output number_to_factorize factor in base 10 */
      printf("\n");

	    clock_t end = clock();
	    double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
      printf("Tempo = %f seconds \n", time_spent); /* show elapsed time */
	  printf("Fim! \n");
	  
				
      mpz_clear(prime_number);  
      mpz_clear(number_to_factorize);
      return 0;
      }
    else
    {	    
      mpz_nextprime (prime_number , prime_number); /* find next prime number */
      mpz_add_ui(count,count,1); /* Count how many prime numbers are being evaluated */
      
      if (mpz_divisible_ui_p(count,1000000) != 0) /* Display every 1,000,000th prime */
      {
        printf("Prime = ");
        mpz_out_str(stdout,10,prime_number); /* output prime_number factor in base 10 */
	    printf("\n");
	    printf("Count = ");
        mpz_out_str(stdout,10,count); /* output count in base 10 */
	    printf("\n");
	    clock_t elapsed_time = clock();
	    double time_spent = (double)(elapsed_time - begin) / CLOCKS_PER_SEC;
        printf("Tempo = %f seconds \n", time_spent); /* show elapsed time */
      }

    while (mpz_divisible_p(number_to_factorize,prime_number) != 0) /* returns non-zero if number_to_factorize is divisible by prime_number */
    {
	  	  mpz_out_str(stdout,10,prime_number); /* output prime_number factor in base 10 */
      printf("\n");
    if (mpz_probab_prime_p(prime_number , 40) == 2)
    { 
      printf(" - Authentic prime!"); /* check if it is definately a prime or if it is a probabilistic prime */
      printf("\n");
    }
    mpz_cdiv_q(number_to_factorize,number_to_factorize,prime_number);  /* number_to_factorize = number_to_factorize / prime_number */ 
	
	}
    }
  }
}