import java.util.ArrayList;
import java.util.List;

/**
 * This is a serial version of Sieve of Eratosthenes algorithm for generating
 * prime numbers.
 */
public class SieveSerial {

    public static void main(String[] args) {
        final int limit = 600000;
        System.out.println("SieveSerial.main: limit = " + limit);

        for (int iter = 0; iter < 8; iter++) {
            final long startTime = System.nanoTime();

            final List<Integer> localPrimes = new ArrayList<Integer>();
            localPrimes.add(2);
            for (int i = 3; i <= limit; i += 2) {
                checkPrime(i, localPrimes);
            }

            final long endTime = System.nanoTime();
            final long execTime = (long) ((endTime - startTime) / 1e6);

            System.out.println("SieveSerial.main: num primes = " + localPrimes.size());
            System.out.println("Iteration-" + iter + " Exec Time = " + execTime + " ms.");
        }
    }

    /**
     * Checks if the candidate is a prime, where the possible prime factors
     * are provided in the primesList
     */
    private static void checkPrime(int candidate, List<Integer> primesList) {
        boolean isPrime = true;
        //for (Iterator<Integer> i = primesList.iterator(); i.hasNext(); ) {
        int s = primesList.size();
        for (int i = 0; i < s; ++i) {
            Integer loopPrime = primesList.get(i);
            if (candidate % loopPrime.intValue() == 0) {
                isPrime = false;
                break;
            }
        }
        if (isPrime) {
            primesList.add(candidate);
        }
    }

}