Givaro
examples/Integer/nb_primes.C

NO DOC

// Copyright(c)'1994-2009 by The Givaro group
// This file is part of Givaro.
// Givaro is governed by the CeCILL-B license under French law
// and abiding by the rules of distribution of free software.
// see the COPYRIGHT file for more details.
#include <iostream>
#include "givaro/givintprime.h"
#include "givaro/givtimer.h"
using namespace Givaro;
inline Integer GIVMAX(const Integer& a, const Integer& b) { return (a<b?b:a); }
int main(int argc, char** argv)
{
Integer m, tp = 2, ttp=1, np;
if (argc > 1)
np = Integer(argv[1]);
else
std::cin >> np;
if (argc > 2)
m = GIVMAX(1,Integer(argv[2]));
else
m = 2;
Integer nf = m;
unsigned long long nb = (IPD.isprime(m)?1:0);
Timer tim; tim.clear(); tim.start();
for (;m < np; tp *= 2) {
std::cout << nb << " primes between " << nf << " and " << m << "\t\t == nextprime(" << (ttp+nf-1) << ")" << std::endl; ttp = tp;
for (;(m < np) && (m < (nf+tp)); ++nb)
IPD.nextprimein(m);
}
tim.stop();
std::cout << (m>np?nb-1:nb) << " primes between " << nf << " and " << np << std::endl << tim << std::endl;
return 0;
}