public class OurArrayList {

    // This is the array in which we'll store the integers.
    Integer[] data = new Integer [1];

    // Initially, there are none.
    int numItems = 0;


    public void add (Integer K)
    {
        if (numItems >= data.length) {
            // Need more space. Let's double it.
            int [] data2 = new int [2 * data.length];
            // Copy over data into new space.
            for (int i=0; i<data.length; i++) {
                data2[i] = data[i];
            }
            // Make the new array the current one.
            data = data2;
        }
        
        data[numItems] = K;
        numItems ++;
    }


    public int size ()
    {
	return numItems;
    }


    public Integer get (int i)
    {
	return data[i];
    }


    public boolean contains (Integer K)
    {
	// Note: we need to use numItems instead of strings.length
	for (int i=0; i<numItems; i++) {
	    if ( data[i].equals(K) ) {
		return true;
	    }
	}
	return false;
    }


    public String toString ()
    {
        if (numItems == 0) {
            return "Empty";
        }
        
        String s = "List: ";
        for (int i=0; i<numItems; i++) {
            s += " " + data[i];
        }
        return s;
    }
    

}