Assume we are using quicksort to sort an array in ascending

Assume we are using quicksort to sort an array in ascending order. Into which array location does quicksort’s strategy place a pivot element after partitioning?

lowest index in array still available

highest index in array still available

closer to its correct final location

its final correct location

1 points   

QUESTION 2

Complete the following code that is intended to provide a comparator interface that will be used to create an object that implements the Comparator interface so that object can compare Auto objects.

public class Comparator<Auto>

public class Comparator<Auto> implements Comparator

public interface Auto<Comparator>

public interface Comparator<Auto>

1 points   

QUESTION 3

Which selection sort iteration guarantees the array is sorted for a 10-element array?

9th iteration

10th iteration

1st iteration

impossible to tell

1 points   

QUESTION 4

In the textbook, we found that the number of element visits for merge sort totaled

n + 5nlog2n. Let’s consider sorting 1024 elements. How many visits are needed?

1.024

6,144

51,200

52,224

1 points   

QUESTION 5

Can you search the following array using binary search?

Yes. Binary search can be applied to any array.

No. Binary search can be applied to a sorted array only.

Yes, but the algorithm runs slower because the array is in descending order.

No, negative numbers are not allowed because they indicate that a value is not present.

1 points   

QUESTION 6

Given the following code snippet for searching an array:

What value will pos have when this code is executed?

0

1

-1

-2

1 points   

QUESTION 7

Suppose you have a phone number and need to find the address that it corresponds to. If there are 2,000,000 entries, how many do you expect to search in a printed phone directory before finding the address you are looking for?

Approximately 50,000 records.

Approximately 75,000 records.

Approximately 1,000,000 records.

Approximately 1,200,000 records.

1 points   

QUESTION 8

In each iteration, selection sort places which element in the correct location?

The smallest in the array.

The smallest element not yet placed in prior iterations.

The largest element in the array.

A random element.

1 points   

QUESTION 9

Suppose an array has n elements. We visit element #1 one time, element #2 two times, element #3 three times, and so forth. How many total visits will there be?

2n

n(n+1)/2

n2

n3

1 points   

QUESTION 10

After one iteration of selection sort working on an array of 10 elements, what must hold true?

The array cannot be sorted.

One element must be correctly placed.

At least two elements are correctly placed.

The largest element is correctly placed.

1 points   

QUESTION 11

If the Arrays static method binarySearch is called on an array of 10 elements and returns a value of 10, what can be concluded?

I the element is not found

II that value cannot be returned from method binarySearch

III if added, the element would be the largest element in the array

I

II

III

I and III

1 points   

QUESTION 12

A version of which sort algorithm is used in the sort method in the Java Arrays class?

merge sort

quicksort

selection sort

insertion sort

1 points   

QUESTION 13

Consider the following code snippet:

What sort algorithm is used in this code?

insertion sort

selection sort

merge sort

quicksort

1 points   

QUESTION 14

Which of the following arrays can be used in a call to the Arrays.sort method?

I Any array with primitive numeric data, such as int, double, …

II Arrays of String or numeric wrapper classes like, Integer, Double, …

III Any class that implements the Comparable interface

I

II

I and II

I, II and III

1 points   

QUESTION 15

If a call to the Arrays static method binarySearch returns a value of -10, what can be concluded?

I the element is not in the array

II the element is at index 10

III the element can be inserted at index 9

I

II

III

I and III

1 points   

QUESTION 16

Another name for linear search is ____ search.

sorted

sequential

random

binary

1 points   

QUESTION 17

After 9 iterations of selection sort working on an array of 10 elements, what must hold true?

The largest element is correctly placed by default.

One more iteration is needed to complete the sort.

The smallest element is incorrectly placed.

The largest element is incorrectly placed.

1 points   

QUESTION 18

Suppose a developer gets class XYZ files and documentation from a subcontractor. This class does not implement the Comparable interface. What must be true in order for the developer to sort an array of XYZ objects without modifying the xyz class?

The XYZ class must implement the Sortable interface.

XYZ objects must be randomly distributed.

XYZ objects must be ordered.

The developer must supply a comparator object belonging to a class that implements the Comparator<XYZ> interface.

1 points   

QUESTION 19

Consider an array with n elements. If we visit each element n times, how many total visits will there be?

n

2n

nn

n2

1 points   

QUESTION 20

Suppose we are using binary search on an array with approximately 1,000,000 elements. How many visits should we expect to make in the worst case?

1

16

20

30

1 points   

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		lowest index in array still available
		highest index in array still available
		closer to its correct final location
		its final correct location

Solution

1. highest index in array still available

2. public class Comparator<Auto> implements Comparator

3. 9th iteration

4. 6,144

5. Yes, but the algorithm runs slower because the array is in descending order.

6. 1

7. Approximately 75,000 records.

8. The largest element in the array.

9. n(n+1)/2

10. At least two elements are correctly placed.

11. I and III

12. selection sort

13. quicksort

14. I and II

15. I and III

16. sequential

17. One more iteration is needed to complete the sort.

18. XYZ objects must be randomly distributed.

19. 2n

20. 20