PrimeSieve.java in pgm

PrimeSieve.java

public class PrimeSieve 

{

 public static void main(String[] args) 

{ 

        int N = Integer.parseInt(args[0]);

                     boolean[] isPrime = new boolean[N + 1];

        for (int i = 2; i <= N; i++) 

        {

            isPrime[i] = true;

        }

                     for (int i = 2; i*i <= N; i++) 

            {

                        if (isPrime[i]) 

            {

                for (int j = i; i*j <= N; j++) 

            {

                    isPrime[i*j] = false;

                }

            }

        }

                      int primes = 0;

        for (int i = 2; i <= N; i++) 

         {

            if (isPrime[i]) primes++;

         }

        System.out.println("The number of primes <= " + N + " is " + primes);

    } 

}