Arrays Test Part 2
By Mickey Arnold
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Last updated 10 months ago
2 Questions
ARRAY TEST FREE RESPONSE - A
The following Numbers class will be used to analyze and retrieve sets of numbers.
public class Numbers
{
/** @param num is a positive non-decimal value
* Precondition : num >= 0
* @return true if the sum of the digit divisors of num is odd
@return false if the sum of the digit divisors of num is even
*/
public static boolean isGoofy(int num)
{
/* to be implemented in part(a) */
}
/* @param count is a positive non-decimal value
* Precondition : count > 0
* @return an array containing count Goofy numbers
*/
public static int[] getSomeGoofyNumbers(int count)
{
/* to be implemented in part(b) */
}
// There may be variables / fields, constructors, and methods that are not shown.
}
1 point
1
Question 1
1.
A. Write the Numbers method isGoofy(), as started below. isGoofy() will receive an integer and determine if that integer is goofy or not goofy.
A goofy number is any number that has a sum of its digit divisors that is odd. The sum of the digit divisors must be greater than zero.
The number 12 has 2 digits – 1 and 2. The number 123 has 3 digits - 1,2, and 3.
The number 26 has 2 digits – 2 and 6. The number 26 is only divisible by 2.
The call isGoofy(12) would return true as 12 has a digit divisor sum of 3 – [1,2] which is odd.The call isGoofy(15) would return false as 15 has a digit divisor sum of 6 – [1,5] which is even.The call isGoofy(26) would return false as 26 has a digit divisor sum of 2 – [2] which is even.
The call isGoofy(271) would return true as 271 has a digit divisor sum of 1 – [1] which is odd.The call isGoofy(1234) would return true as 1234 has a digit divisor sum of 3 – [1,2] which is odd.
/** @param num is a positive non-decimal value* Precondition : num >= 0* @return true if the sum of the digits of num is odd@return false if the sum of the digits of num is even*/public static boolean isGoofy(int num){ //code goes here}
A. Write the Numbers method isGoofy(), as started below. isGoofy() will receive an integer and determine if that integer is goofy or not goofy.
A goofy number is any number that has a sum of its digit divisors that is odd. The sum of the digit divisors must be greater than zero.
The number 12 has 2 digits – 1 and 2. The number 123 has 3 digits - 1,2, and 3.
The number 26 has 2 digits – 2 and 6. The number 26 is only divisible by 2.
The call isGoofy(12) would return true as 12 has a digit divisor sum of 3 – [1,2] which is odd.
The call isGoofy(15) would return false as 15 has a digit divisor sum of 6 – [1,5] which is even.
The call isGoofy(26) would return false as 26 has a digit divisor sum of 2 – [2] which is even.
The call isGoofy(271) would return true as 271 has a digit divisor sum of 1 – [1] which is odd.
The call isGoofy(1234) would return true as 1234 has a digit divisor sum of 3 – [1,2] which is odd.
/** @param num is a positive non-decimal value
* Precondition : num >= 0
* @return true if the sum of the digits of num is odd
@return false if the sum of the digits of num is even
*/
public static boolean isGoofy(int num)
{
//code goes here
}
1 point
1
Question 2
2.
B. Write the Numbers method getSomeGoofyNumbers(), as started below. getSomeGoofyNumbers() will receive a count of how many Goofy numbers to return.The call getSomeGoofyNumbers(3) would return [1, 3, 5].The call getSomeGoofyNumbers(15) would return [1, 3, 5, 7, 9, 10, 12, 13, 14, 16, 17, 18, 19, 21, 25].
You must call the method from part a, assuming the method works as specified regardless of what you wrote.
/* @param count is a positive non-decimal value* Precondition : stop > 0* @return an array containing count Goofy numbers*/public static int[] getSomeGoofyNumbers(int count){ //code goes here}
B. Write the Numbers method getSomeGoofyNumbers(), as started below. getSomeGoofyNumbers() will receive a count of how many Goofy numbers to return.
The call getSomeGoofyNumbers(3) would return [1, 3, 5].
The call getSomeGoofyNumbers(15) would
return [1, 3, 5, 7, 9, 10, 12, 13, 14, 16, 17, 18, 19, 21, 25].
You must call the method from part a, assuming the method works as specified regardless of what you wrote.
/* @param count is a positive non-decimal value
* Precondition : stop > 0
* @return an array containing count Goofy numbers
*/
public static int[] getSomeGoofyNumbers(int count)
{
//code goes here
}