Prime Numbers 2 - 1000

Code:
#include <iostream>

using std::cout;
using std::cin;
using std::endl;

int main()
{
    int array_size = 1000;
    bool num[ array_size ];

    for ( int a = 2; a < array_size; a++ )  // Set all elements to 1
    {
        num[ a ] = 1;
    }

    for ( int b = 2; b < array_size / 2; b++ )
    {
        if ( num[ b ] == 1 ) 
        {
            for ( int c = b; c < array_size; c + b )
            {
                num[ c ] = 0;
            }
        }
     }    

    for ( int d = 2; d < array_size; d++ )
    {
        if ( num[ d ] == 1 )
        {
            cout << d << endl;
        }
    }

    cin.get();
    return 0;
}
No output.
Maybe the fact that it's 2 am whenever I try to do a question in the book doesn't help.