/** Class MyBetterIntList
 */
 
import java.util.ArrayList;
public class MyBetterIntList {
   
    // field to hold the data array
    private int[] data;
    private int num_elems;
   
    /** constructor for MyBetterIntList
     * make an empty list
     */
    public MyBetterIntList() {
        this.data = new int[10];
        this.num_elems = 0;
    }
    
    /** Return the String rep of the array
     *  @return the string rep of the array
     */
    public String toString() {
        String ret = "";
        int len = this.num_elems;
        for (int i = 0; i<len; i++) {
            ret += this.data[i] + " ";
        }
        return ret;
    }
    
    /** Add x to the end of the list
      * @param x, the int to add
      */
    public void add(int x) {
        if (this.num_elems == this.data.length) {
            int newList[] = new int[2*this.data.length];
            for (int i = 0; i < this.data.length; i++ ) {
                newList[i] = this.data[i];
            }
            this.data = newList;
        }  
        this.data[this.num_elems] = x;
        this.num_elems++;
    }
    
    /** Return the number of elems in the list
     *  @return the number of elems in the list
     */
    public int size() { return this.num_elems; }
    
    /** return true if it is empty, else false
    *   @return  true if it is empty, else false
    */
    public boolean isEmpty() { 
        return this.num_elems == 0;
    }
       
    /** test the class
    */
    public static void main( String[] args ) {
//         MyBetterIntList list = new MyBetterIntList();
//         System.out.println( list );
//         list.add( 10 );
//         list.add( 9 );
//         System.out.println( list );
//         System.out.println( "len is " + list.size() );
//         System.out.println( list.isEmpty() );
        
        // add 1 million integers to an ArrayList
        long startTime = System.currentTimeMillis();
        ArrayList<Integer> aList = new ArrayList<Integer>();
        for (int i =0; i<1000000; i++) {
            //if (i % 10000 == 0) System.out.println(i);
            aList.add(i);
        }
        long endTime = System.currentTimeMillis();
        System.out.println( "Time for ArrayLists: " + (endTime-startTime) );
        
        // add 1 million integers to an ArrayList
        startTime = System.currentTimeMillis();
        MyBetterIntList list = new MyBetterIntList();
        for (int i =0; i<1000000; i++) {
            //if (i % 10000 == 0) System.out.println(i);
            list.add(i);
        }
        endTime = System.currentTimeMillis();
        System.out.println( "Time for MyBetterIntList: " + (endTime-startTime) );
        
    } // end main
    
} // end class