for( int a = 1000; a < 10000; ++a )
    {
        int b = a;
        int array[4] = { 0, 0, 0, 0 };
        for( int i = 0; i < 4; ++i )
        {
            int iDig = b % 10;
            b /= 10;
            array[i] = iDig;
        }
        // do the first 2 and last 2 match?
        if( array[0] == array[1] && array[2] == array[3] )
        {
            // is it a perfect square?
            double dVal = sqrt( (double)a );
            if( dVal == floor( dVal ) )
                printf( "%d is a perfect square (%f)\n", a, dVal );
        }
    }