Quick remodel of primes test

PrimesQuick-28sec-5M

#include <stdio.h>
#include <windows.h> // GetTickCount();

struct primes {
	int last;
	int checkTo;
	long long primes[100000];
};

struct primes * getPrimes( void ) {
	struct primes *p = malloc( sizeof *p );
	p->last = 0;
	p->checkTo = 0;
	return p;
}

int total = 0;

int main()
{
	long long k;
	int sets = 0;
	int start = GetTickCount();
	struct primes *allprimes[1000];
	struct primes *primes = getPrimes();


	for (k = 2; k < 86028121; k++)
	{
		int s;
		if( primes->last == 100000 ) {
			allprimes[sets++] = primes;
			primes = getPrimes();
		}
		for( s = 0; s < sets; s++ )
			if (!isPrime(allprimes[s], k)) {
				break;
			}
		if( s == sets )
			if (isPrime(primes, k))
			{
				primes->primes[primes->last++] = k;
				total++;
				for( s = 0; s < sets; s++ ) {
					int p;
					for( p = allprimes[s]->checkTo; p < allprimes[s]->last; p++ ) {
						if(  allprimes[s]->primes[p] * allprimes[s]->primes[p] > k ) {
							allprimes[s]->checkTo = p;
							break;
						}	
					}
				}
				if( s == sets )
				{				
					int p;
					for( p = primes->checkTo; p < primes->last; p++ ) {
						if(  primes->primes[p] * primes->primes[p] > k )
							break;
					}
					primes->checkTo = p;
				}
				//printf("X");
			} else {
				//printf("X");
				//printf("O");
			}
		if( ( (k%200000)==0 ) )printf( "%d   (found)%d  (checked) %lld of %d %g\n", GetTickCount() - start, total, k, 86028121, ((100.0*((double)k))/86028121.0) );
	}  
}

int isPrime(struct primes *primes, long long number)
{
	int i;
	long long *pll = primes->primes;
	for (i = 0; i < primes->checkTo; pll++,i++ )
	{
		 if (number % *pll == 0)
		 {
			  return 0;
		 }
	}
	return 1;
}