import element.*;

public class Sieve
{
    public static void initialize(boolean prime[])
    // pre: prime is an array of booleans
    // post: all entries in prime are optimistically set to true
    {
        int n;
        // initialize the array (entries 0,1 unused)
        for (n = 2; n < prime.length; n++)
        {
            prime[n] = true;
        }
    }

    public static void crossOut(int n, boolean prime[])
    // pre: n < prime.length
    // post: all nontrivial multiples (m) of n are identified as composite
    {
        int m;

        for (m = 2*n; m < prime.length; m += n)
        {
            prime[m] = false;
        }
    }

    public static void print(ConsoleWindow c, boolean prime[])
    // pre: c is non-null, prime is a computed sieve
    // post: the indices of the true entries of prime are printed on c
    {
        int n;
        // print out primes: uncrossed numbers
        for (n = 2; n < prime.length; n++)
        {
            if (prime[n]) {
                c.out.print(n+" ");
            }
        }
        c.out.println();
    }

    public static void main(String args[])
    // post: compute the primes between 2 and max, inclusive
    {
        ConsoleWindow c = new ConsoleWindow();
        final int max = 100;
        boolean prime[] = new boolean[max+1];
        int n;

        // assume all values are potentially prime
        initialize(prime);

        // cross out multiples of uncrossed numbers
        for (n = 2; n <= max; n++)
        {
            if (prime[n]) // needn't cross out multiples of composites
            {
                crossOut(n,prime);
            }
        }

        // print out indices of entries that remain "prime"
        print(c,prime);
    }
}
/*
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 
 */