Question 1

In the code for the keysToIndexes function, what is the missing code? def keysToIndexes(keys, n):
Return

Accepted Answer

A)  list(map(lambda key: key % n, keys)) 
B)  list(map(lambda key: keys, key % n )) 
C)  map(list(lambda key: key % n, keys)) 
D)  map(list(lambda key % n: keys, key)) 
A)  list(map(lambda key: key % n, keys)) 
B)  list(map(lambda key: keys, key % n )) 
C)  map(list(lambda key: key % n, keys)) 
D)  map(list(lambda key % n: keys, key))

Question 2

If a hashing function runs in constant time, insertions, accesses, and removals of the associated keys are O(1).

Accepted Answer

A) True 
 B)False

Question 3

As the density, or number of keys relative to the length of an array decreases, so does the probability of hashing collisions.

Accepted Answer

A) True 
 B)False

Question 4

When considering an insertion into a set using a hash function and linear probing, which of the following is defined as the position where the item should go if the has function works perfectly?

Accepted Answer

A)  absolute index 
B)  probe index 
C)  zero index 
D)  home index 
A)  absolute index 
B)  probe index 
C)  zero index 
D)  home index

Question 5

Which of the following is the best array length to reduce the probability of collisions given the set [ 8, 6, 18, 9, 14, 23 ]?

Accepted Answer

A)  9 
B)  8 
C)  11 
D)  12 
A)  9 
B)  8 
C)  11 
D)  12

Question 6

The __sub__ method of the set class returns a set containing items in s1 that are not in s2.

Accepted Answer

A) True 
 B)False

Question 7

Which statement is true when considering a hashing strategy and the density of the keys/array length relationship?

Accepted Answer

A)  as the density decreases, the probability of collisions decreases 
B)  as the density increases, the probability of collisions decreases 
C)  as the density decreases, the probability of collisions increases 
D)  as the density increases, the probability of collisions stays the same 
A)  as the density decreases, the probability of collisions decreases 
B)  as the density increases, the probability of collisions decreases 
C)  as the density decreases, the probability of collisions increases 
D)  as the density increases, the probability of collisions stays the same

Question 8

A hashing function acts on a given key by returning its absolute position in an array.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following is true about sets?

Accepted Answer

A)  the items in a set are arranged in order 
B)  the difference and subset operations on a set are symmetric 
C)  there are no duplicate items in a set 
D)  there is no standard set class in Python 
A)  the items in a set are arranged in order 
B)  the difference and subset operations on a set are symmetric 
C)  there are no duplicate items in a set 
D)  there is no standard set class in Python

Question 10

In the hashing implementation of a set, the Bag class is used to represent an item and a pointer to the next item in a chain.

Accepted Answer

A) True 
 B)False

Question 11

The entries in a dictionary consist of a key, a value, and an index.

Accepted Answer

A) True 
 B)False

Question 12

What strategy does the hashing implementation of a dictionary use?

Accepted Answer

A)  a binary search tree 
B)  quadratic probing 
C)  linear probing/bucket 
D)  bucket/chaining 
A)  a binary search tree 
B)  quadratic probing 
C)  linear probing/bucket 
D)  bucket/chaining

Question 13

For a given set s , which method returns True if item is in s , or False otherwise.

Accepted Answer

A)  s.__contains__(item) 
B)  s.__iter__(item) 
C)  s = set() 
D)  S1.__sub__(s2) 
A)  s.__contains__(item) 
B)  s.__iter__(item) 
C)  s = set() 
D)  S1.__sub__(s2)

Question 14

In the algorithm for the __contains method of the hashing implementation of sets, what is the first step in the algorithm?

Accepted Answer

A)  set foundNode to table[ index ] 
B)  set priorNode to foundNode 
C)  set index to the home index of the item 
D)  set foundNode to foundNode.next 
A)  set foundNode to table[ index ] 
B)  set priorNode to foundNode 
C)  set index to the home index of the item 
D)  set foundNode to foundNode.next

Question 15

In the hashing implementation of a dictionary, the data field of each node in a chain contains an Entry object.

Accepted Answer

A) True 
 B)False

Question 16

For key values of 84 and 108 and a hashing function of key % 12 , what is the result?

Accepted Answer

A)  indexes of 7 and 9 
B)  indexes of 0 and 1 
C)  a collision 
D)  indexes of 12 and 14 
A)  indexes of 7 and 9 
B)  indexes of 0 and 1 
C)  a collision 
D)  indexes of 12 and 14

Question 17

In Python's dict type, values are inserted or replaced at a given location using the index operator {} .

Accepted Answer

A) True 
 B)False

Question 18

The AbstractSet class is a subclass of AbstractCollection because AbstractSet introduces new instance variables for data.

Accepted Answer

A) True 
 B)False

Question 19

Two strings that are anagrams will return a unique integer value when the sum of the ASCII values is calculated.

Accepted Answer

A) True 
 B)False

Question 20

Which method in the interface for a dictionary collection returns an iterator on the key/value pairs in the dictionary?

Accepted Answer

A)  keys() 
B)  entries() 
C)  pairs() 
D)  values() 
A)  keys() 
B)  entries() 
C)  pairs() 
D)  values()

In the code for the keysToIndexes function, what is the missing code? def keysToIndexes(keys, n): Return < missing code >

If a hashing function runs in constant time, insertions, accesses, and removals of the associated keys are O(1).

As the density, or number of keys relative to the length of an array decreases, so does the probability of hashing collisions.

When considering an insertion into a set using a hash function and linear probing, which of the following is defined as the position where the item should go if the has function works perfectly?

Which of the following is the best array length to reduce the probability of collisions given the set [ 8, 6, 18, 9, 14, 23 ]?

The sub method of the set class returns a set containing items in s1 that are not in s2.

Which statement is true when considering a hashing strategy and the density of the keys/array length relationship?

A hashing function acts on a given key by returning its absolute position in an array.

Which of the following is true about sets?

In the hashing implementation of a set, the Bag class is used to represent an item and a pointer to the next item in a chain.

The entries in a dictionary consist of a key, a value, and an index.

What strategy does the hashing implementation of a dictionary use?

For a given set s , which method returns True if item is in s , or False otherwise.

In the algorithm for the __contains method of the hashing implementation of sets, what is the first step in the algorithm?

In the hashing implementation of a dictionary, the data field of each node in a chain contains an Entry object.

For key values of 84 and 108 and a hashing function of key % 12 , what is the result?

In Python's dict type, values are inserted or replaced at a given location using the index operator {} .

The AbstractSet class is a subclass of AbstractCollection because AbstractSet introduces new instance variables for data.

Two strings that are anagrams will return a unique integer value when the sum of the ASCII values is calculated.

Which method in the interface for a dictionary collection returns an iterator on the key/value pairs in the dictionary?

Basic Python Programming

An Overview of Collections

Searching, Sorting, and Complexity Analysis

Arrays and Linked Structures

Interfaces, Implementations, and Polymorphism

Inheritance and Abstract Classes

Stacks

Queues

Lists

Trees

Graphs

Filters

Exam 11: Sets and Dictionaries

In the code for the keysToIndexes function, what is the missing code? def keysToIndexes(keys, n): Return < missing code >

If a hashing function runs in constant time, insertions, accesses, and removals of the associated keys are O(1).

As the density, or number of keys relative to the length of an array decreases, so does the probability of hashing collisions.

When considering an insertion into a set using a hash function and linear probing, which of the following is defined as the position where the item should go if the has function works perfectly?

Which of the following is the best array length to reduce the probability of collisions given the set [ 8, 6, 18, 9, 14, 23 ]?

The __sub__ method of the set class returns a set containing items in s1 that are not in s2.

Which statement is true when considering a hashing strategy and the density of the keys/array length relationship?

A hashing function acts on a given key by returning its absolute position in an array.

Which of the following is true about sets?

In the hashing implementation of a set, the Bag class is used to represent an item and a pointer to the next item in a chain.

The entries in a dictionary consist of a key, a value, and an index.

What strategy does the hashing implementation of a dictionary use?

For a given set s , which method returns True if item is in s , or False otherwise.

In the algorithm for the __contains method of the hashing implementation of sets, what is the first step in the algorithm?

In the hashing implementation of a dictionary, the data field of each node in a chain contains an Entry object.

For key values of 84 and 108 and a hashing function of key % 12 , what is the result?

In Python's dict type, values are inserted or replaced at a given location using the index operator {} .

The AbstractSet class is a subclass of AbstractCollection because AbstractSet introduces new instance variables for data.

Two strings that are anagrams will return a unique integer value when the sum of the ASCII values is calculated.

Which method in the interface for a dictionary collection returns an iterator on the key/value pairs in the dictionary?

Basic Python Programming

An Overview of Collections

Searching, Sorting, and Complexity Analysis

Arrays and Linked Structures

Interfaces, Implementations, and Polymorphism

Inheritance and Abstract Classes

Stacks

Queues

Lists

Trees

Graphs

Filters

The sub method of the set class returns a set containing items in s1 that are not in s2.