/* mpfr_pi.c : This program is treated as public domain software */

#include <stdio.h>
#include <math.h>
#include <time.h>
#include "mpfr.h"

void usage(const char *progname)
{
	printf("$ %s [# of decimal digit for PI]\n", progname);
}

int main(int argc, char *argv[])
{
	long int digit, bit;
	clock_t begin, end;
	mpfr_t pi;

	if(argc <= 1)
	{
		usage(argv[0]);
		return 0;
	}

	/* # of decimal digit to # of bits */
	bit = (long int)ceil((double)atoi(argv[1]) / log10(2.0));
	printf("# of decimal digits: %d\n", atoi(argv[1]));
	printf("# of bits          : %d\n", bit);

	/* Initialize */
	mpfr_init2(pi, bit);

	/* Get pi */
	begin = clock();
	mpfr_const_pi(pi, GMP_RNDN);
	end = clock();

	/* Output */
	printf("Time               : %6.3f\n", (double)(end - begin) / CLOCKS_PER_SEC);

	/* Remove comment if you want to output pi */
	//mpfr_out_str(stdout, 10, 0, pi, GMP_RNDN);
	printf("\n");

	/* Clear */
	mpfr_clear(pi);

	return 0;
}