/* * Created on May 19, 2004 * * Simple implementation of the sieve of Eratosthenes *//** * @author robert * * This class contains only static members. pi(n) returns the number of  * primes less or equal to n.  * Note that this program does not handle large n.   */public class Eratosthenes {	public static int pi(int n) {		int sieve[] = new int[n-1];		//initialize the sieve		for (int k=1; k<n; ++k) {			sieve[k-1] = k+1;		}		for (int k=0; k<Math.floor(Math.sqrt(n)); ++k) {			while (sieve[k]==0) ++k;			for (int l=2; l*sieve[k]-2<n-1; ++l) {				sieve[l*sieve[k]-2] = 0;			}		}		//finally count the elements in the sieve		int count = 0;		for (int k=0; k<n-1; ++k) {			if (sieve[k]!=0) {				++count; 			}		}		return count;	}		public static void main(String[] args) {		System.out.println("Pi(100000)="+pi(100000));	}}