Question 1

What type of access does the use of an iterator provide for the elements of a bucket in a hash table?

Accepted Answer

A)  sequential 
B)  semi-random 
C)  random 
D)  sorted 
A)  sequential 
B)  semi-random 
C)  random 
D)  sorted

Question 2

If the current size of an array list is less than the length of the buffer, adding an element at the end of an array list takes ____ time.

Accepted Answer

A)  O(n) 
B)  O(1) 
C)  O(log(n)) 
D)  O(n2) 
A)  O(n) 
B)  O(1) 
C)  O(log(n)) 
D)  O(n2)

Question 3

Which of the following statements about using iterators with hash tables is NOT correct?

Accepted Answer

A)  The iterator must track its position within a node chain in a bucket. 
B)  The iterator must skip over empty buckets. 
C)  Two iterators are required: one to traverse the buckets, and another to traverse the nodes within a bucket. 
D)  The iterator must track the bucket number. 
A)  The iterator must track its position within a node chain in a bucket. 
B)  The iterator must skip over empty buckets. 
C)  Two iterators are required: one to traverse the buckets, and another to traverse the nodes within a bucket. 
D)  The iterator must track the bucket number.

Question 4

In the open addressing technique for handling collisions in a hash table, ____.

Accepted Answer

A)  colliding elements are stored in a nested hash table. 
B)  colliding elements are placed in empty locations in the hash table. 
C)  colliding elements are stored in linked lists associated with the hash code. 
D)  the hash code is compressed to obtain unique hash codes. 
A)  colliding elements are stored in a nested hash table. 
B)  colliding elements are placed in empty locations in the hash table. 
C)  colliding elements are stored in linked lists associated with the hash code. 
D)  the hash code is compressed to obtain unique hash codes.

Question 5

Which operations from the array list data structure could be used in the implementation of the push and pop operations of a stack data structure?
I addLast
II addFirst
III removeFirst

Accepted Answer

A)  I 
B)  II 
C)  I and II 
D)  II and III 
A)  I 
B)  II 
C)  I and II 
D)  II and III

Question 6

Assume that you have a hash table in which there are an average number of collisions. What is the time required to find an element in this hash table?

Accepted Answer

A)  O(n) 
B)  O(n2) 
C)  O(1) 
D)  O(1)+ 
A)  O(n) 
B)  O(n2) 
C)  O(1) 
D)  O(1)+

Question 7

Suppose we maintain two linked lists of length n in random element order. What would be the big-Oh notation for the creating a third list that includes only elements common to both lists, without sorting the first two lists?

Accepted Answer

A)  O(1) 
B)  O(n) 
C)  O(n log2 n) 
D)  O(n2) 
A)  O(1) 
B)  O(n) 
C)  O(n log2 n) 
D)  O(n2)

Question 8

Reading or writing an array list element at an arbitrary index takes ____ time.

Accepted Answer

A)  O(log (n)) 
B)  O(n) 
C)  O(n2) 
D)  O(1) 
A)  O(log (n)) 
B)  O(n) 
C)  O(n2) 
D)  O(1)

Question 9

Assume that you have a hash table in which there are few or no collisions. What is the time required to locate an element in this hash table?

Accepted Answer

A)  O(log n) 
B)  O(n) 
C)  O(n2) 
D)  O(1) 
A)  O(log n) 
B)  O(n) 
C)  O(n2) 
D)  O(1)

Question 10

A stack can be implemented as a sequence of nodes in a linked list or an array list. Which of the following statements about this is correct?

Accepted Answer

A)  If implementing the stack as a linked list, the least expensive approach is to add and remove elements at the end. 
B)  If implementing the stack as an array list, the least expensive approach is to add and remove elements at the end. 
C)  If implementing the stack as an array list, there is no cost difference whether adding and removing elements at the beginning or the end. 
D)  If implementing the stack as a linked list, there is no cost difference whether adding and removing elements at the beginning or the end. 
A)  If implementing the stack as a linked list, the least expensive approach is to add and remove elements at the end. 
B)  If implementing the stack as an array list, the least expensive approach is to add and remove elements at the end. 
C)  If implementing the stack as an array list, there is no cost difference whether adding and removing elements at the beginning or the end. 
D)  If implementing the stack as a linked list, there is no cost difference whether adding and removing elements at the beginning or the end.

Question 11

Which of the following operations from the array list data structure could be used in the implementation of the push and pop operations of a stack data structure?
I addLast
II addFirst
III removeLast

Accepted Answer

A)  I 
B)  II 
C)  I and III 
D)  II and III 
A)  I 
B)  II 
C)  I and III 
D)  II and III

Question 12

Assume that the linked list implementation includes a reference to the last node as well as to the first node. Which of the following statements about the efficiency of the linked list is correct?

Accepted Answer

A)  Adding an element to the middle of the linked list at the current position of the iterator is O(n). 
B)  Removing an element other than the last element from the linked list at the current position of the iterator is O(n). 
C)  Accessing an element in the linked list using an iterator is O(n). 
D)  Adding an element to the end of the linked list is O(1). 
A)  Adding an element to the middle of the linked list at the current position of the iterator is O(n). 
B)  Removing an element other than the last element from the linked list at the current position of the iterator is O(n). 
C)  Accessing an element in the linked list using an iterator is O(n). 
D)  Adding an element to the end of the linked list is O(1).

Question 13

Suppose we maintain a linked list of length n in random element order. What would be the big-Oh notation for an algorithm that prints each list element and the number of times it occurs in the list (without sorting the list)?

Accepted Answer

A)  O(1) 
B)  O(n) 
C)  O(n log2 n) 
D)  O(n2) 
A)  O(1) 
B)  O(n) 
C)  O(n log2 n) 
D)  O(n2)

Question 14

Assume that you have a hash table in which there are few or no collisions. What is the time required to add a new element to this hash table?

Accepted Answer

A)  O(log(n)) 
B)  O(n) 
C)  O(n2) 
D)  O(1) 
A)  O(log(n)) 
B)  O(n) 
C)  O(n2) 
D)  O(1)

Question 15

Which statement about handling collisions in a hash table using the open addressing technique is NOT correct?

Accepted Answer

A)  A colliding element may not be contiguous to the location in which it would normally be placed. 
B)  To find an element, you must search from the hash code location until a match or an empty slot is found. 
C)  To remove an element, you simply empty the slot at which you find it. 
D)  There may be some elements with different hash codes that lie on the same probing sequence. 
A)  A colliding element may not be contiguous to the location in which it would normally be placed. 
B)  To find an element, you must search from the hash code location until a match or an empty slot is found. 
C)  To remove an element, you simply empty the slot at which you find it. 
D)  There may be some elements with different hash codes that lie on the same probing sequence.

Question 16

Assume that you have a hash table in which there are an average number of collisions. What is the time required to remove an element from this hash table?

Accepted Answer

A)  O(n) 
B)  O(n2) 
C)  O(1) 
D)  O(1)+ 
A)  O(n) 
B)  O(n2) 
C)  O(1) 
D)  O(1)+

Question 17

Complete the following code snippet, which is intended to compress a hash code to become a valid array index:
Int h = x.hashCode();
If (h < 0) { h = -h; }
_______________

Accepted Answer

A)  position = arrayLength % h; 
B)  position = arrayLength / h; 
C)  position = h / arrayLength; 
D)  position = h % arrayLength; 
A)  position = arrayLength % h; 
B)  position = arrayLength / h; 
C)  position = h / arrayLength; 
D)  position = h % arrayLength;

Question 18

Array list operations that were studied included adding/removing an element at the end or in the middle, and retrieving the kth element. Which of the following statements about these array list operations is correct?

Accepted Answer

A)  The least expensive operation of an array list is to add an element at the end. 
B)  The least expensive operation of an array list is to remove an element at the end. 
C)  The least expensive operation of an array list is to add an element in the middle. 
D)  The least expensive operation of an array list is to retrieve an arbitrary element. 
A)  The least expensive operation of an array list is to add an element at the end. 
B)  The least expensive operation of an array list is to remove an element at the end. 
C)  The least expensive operation of an array list is to add an element in the middle. 
D)  The least expensive operation of an array list is to retrieve an arbitrary element.

Question 19

Which hash table method(s) will make use of the equals method?
I put
II get
III contains

Accepted Answer

A)  I 
B)  I and II 
C)  III 
D)  I, II and III 
A)  I 
B)  I and II 
C)  III 
D)  I, II and III

Question 20

A doubly-linked list requires that each node maintain two references, one to the next node and one to the previous node. Which of the following statements about a doubly-linked list is NOT correct?

Accepted Answer

A)  If a node's next reference is null, it is at the end of the list. 
B)  To remove a node in the middle of the list, the previous node's next reference must be updated. 
C)  To add a node in the middle of the list, you must update the next reference of the node after which the new node will be added. 
D)  To remove a node in the middle of the list, the previous node's previous reference must be updated. 
A)  If a node's next reference is null, it is at the end of the list. 
B)  To remove a node in the middle of the list, the previous node's next reference must be updated. 
C)  To add a node in the middle of the list, you must update the next reference of the node after which the new node will be added. 
D)  To remove a node in the middle of the list, the previous node's previous reference must be updated.

Exam 16: Basic Data Structures

What type of access does the use of an iterator provide for the elements of a bucket in a hash table?

If the current size of an array list is less than the length of the buffer, adding an element at the end of an array list takes ____ time.

Which of the following statements about using iterators with hash tables is NOT correct?

In the open addressing technique for handling collisions in a hash table, ____.

Which operations from the array list data structure could be used in the implementation of the push and pop operations of a stack data structure? I addLast II addFirst III removeFirst

Assume that you have a hash table in which there are an average number of collisions. What is the time required to find an element in this hash table?

Suppose we maintain two linked lists of length n in random element order. What would be the big-Oh notation for the creating a third list that includes only elements common to both lists, without sorting the first two lists?

Reading or writing an array list element at an arbitrary index takes ____ time.

Assume that you have a hash table in which there are few or no collisions. What is the time required to locate an element in this hash table?

A stack can be implemented as a sequence of nodes in a linked list or an array list. Which of the following statements about this is correct?

Which of the following operations from the array list data structure could be used in the implementation of the push and pop operations of a stack data structure? I addLast II addFirst III removeLast

Assume that the linked list implementation includes a reference to the last node as well as to the first node. Which of the following statements about the efficiency of the linked list is correct?

Suppose we maintain a linked list of length n in random element order. What would be the big-Oh notation for an algorithm that prints each list element and the number of times it occurs in the list (without sorting the list)?

Assume that you have a hash table in which there are few or no collisions. What is the time required to add a new element to this hash table?

Which statement about handling collisions in a hash table using the open addressing technique is NOT correct?

Assume that you have a hash table in which there are an average number of collisions. What is the time required to remove an element from this hash table?

Complete the following code snippet, which is intended to compress a hash code to become a valid array index: Int h = x.hashCode(); If (h < 0) { h = -h; } _______________

Array list operations that were studied included adding/removing an element at the end or in the middle, and retrieving the kth element. Which of the following statements about these array list operations is correct?

Which hash table method(s) will make use of the equals method? I put II get III contains

A doubly-linked list requires that each node maintain two references, one to the next node and one to the previous node. Which of the following statements about a doubly-linked list is NOT correct?

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