PRACTICE EXAM 2 SAMPLE ANSWERS

1a) 1+4+7+10+13 = 35

 b)      total
    5*2 =  10
   10*2 =  20
   20*2 =  40
   40*2 =  80
   80*2 =  160 <-- 100 never reached. infinite loop. Nothing prints out

 c)      result
   1+1  =   2
   2+2  =   4
   4+4  =   8
   8+8  =  16
   16+16 =  32
   32+32 =  64
   64+64 =  128 > 100. Exit loop. result = 128

 d) i is not greater than 1. Loop never gets executed. print out initial 
    value of product = 1. 

2a) i  j  sum   product
    1  1   1       1
                   1    
    2  1   1       1    
    2  2   3       1
                   3
    3  1   1       3
    3  2   3       3
    3  3   6       3
                   18

    product = 18

 b) i  j  sum   product
    1  1   1       1
                   1    
    2  1   2       1    
    2  2   4       1
                   4
    3  1   5       4
    3  2   7       4
    3  3   10      4
                   40

    product = 40

    It does not yield the same answer since sum is not reset back to 0
    each time the outer loop repeats. So sum continues to get larger
    and larger, making the product larger than before.

 c) 
int product = 1;
int i=1;
		
while (i<4)
{
	int sum = 0;
	int j = 1;
	while (j<=i)
	{
	    sum += j;
	    j++;
	}
	product *= sum; 
	i++;
} 
System.out.println(product); 


3a) score = new int[30];

 b) for (int i=0; i<score.length; i++){
	score[i] =(int)((Math.random()*20)+1)*5;
    }  

 c) int max = score[0];
    for (int i=1; i<score.length; i++)
    {
        if (score[i] > max) 
            max = score[i];
    }


4.
    public static int countTemps(double[] tempArray, double threshold)
    {
        int count = 0;

        for (int i = 0; i < tempArray.length; i++)
        {
             if (threshold < tempArray[i])
                 count = count+1;
        }

        return count;
    }

    public static void main(String[] args) 
    {
        Scanner scan = new Scanner(System.in);
	double[] tempValues = { 23.1, 15.3, 64.4, 23.6, 86.4, 49.3, 77.3 };
        System.out.println("Input the temperature threshold cutoff: ");
        double cutoff = scan.nextDouble();
        System.out.println("The number of temperatures above the threshold is "
             + countTemps(tempValues, cutoff));
    }


5. 

public class MyDiceGame {
	
	public static void main(String[] args) {
		Die die1 = new Die();
		Die die2 = new Die();
		int round = 0;
		int score = 0;
		
		while (round<10 && score<70)
		{
			round++;
			int value1 = die1.roll();
			int value2 = die2.roll();

			System.out.println();
			System.out.println("Round "+round);
			
			if (value1!=value2)
				score = score+value1+value2;			
			else 
			{
				if (score<10)
					score = 0;
				else 
					score -= 10;
			}
			
			System.out.println("Your new score is: " + score);
		}
		
		if (score>=70)
			System.out.println("WINNER");
		else
			System.out.println("LOSER");
    }
}