public class StudentRecord
{
	private int[] scores;
	public StudentRecord(int[] scores) {
		this.scores = scores;
	}
	/**
	 * returns the average (arithmetic mean) of the 
	 * whose subscripts are between first and last,
	 * precondition: 0 <= first <= last < scores.length
	 */
	public double average(int first, int last)
	{
		// part (a) 
		return 0D;
	}
	/**
	 * returns true if each successive value in scores is greater
	 * than or equal to the previous value;
	 * otherwise, returns false
	 */
	public boolean hasImproved()
	{
		//part (b)
		return false;
	    
	}
	/**
	 * if the values in scores have improved, returns the average
	 * of the elements in scores with indexes greater than or equal
	 * to scores.length/2; 
	 * otherwise, returns the average of all of the values in scores
	 * 
	 */
	public double finalAverage()
	{
		// part (c)
		return 0D;
	}
    
	public static void main (String[] args)
    {
     //three different ways to make our int arrays
     int[] a1={50, 50, 20, 80, 53}; 
     int a2[]={20, 50, 50, 53, 80};    
     int[] a3=new int[4];
     a3[0]=20;
     a3[1]=a3[2]=50;
     a3[3]=80;
     
     StudentRecord s1=new StudentRecord(a1);
     StudentRecord s2=new StudentRecord(a2);
     StudentRecord s3=new StudentRecord(a3);

     System.out.println("s1 improved? "+ passFail(false, s1.hasImproved()));
     System.out.println("s2 improved? "+ passFail(true, s2.hasImproved()));
     System.out.println("s3 improved? "+ passFail(true, s3.hasImproved()));
     
     System.out.println("\ns1 average(0,1): "+ passFail(50, s1.average(0, 1)));
     System.out.println("s2 average(1,2): "+ passFail(50, s2.average(1, 2)));
     System.out.println("s3 average(0,2): "+ passFail(40, s3.average(0, 2)));
     
     
     System.out.println("\ns1 final average: " + passFail(50.6, s1.finalAverage()));
     System.out.println("s2 final average: " + passFail(61.0, s2.finalAverage()));
     System.out.println("s3 final average: " + passFail(65.0, s3.finalAverage()));
    }
    public static String passFail(double expected, double actual) {
    	String result = actual + " (should be "+ expected+ ")";
    	if (expected - actual == 0)
    		return  result + " - PASS!";
    	return  result + " - FAIL...";
    }
    public static String passFail(boolean expected, boolean actual) {
    	String result = actual + " (should be "+ expected+ ")";
    	if (expected == actual)
    		return result + " - PASS!";
    	return result + " - FAIL...";
    }



}