7)

The code for the add method for the ArrayBag class is shown below. What is the missing code?

def add(self, item):

self.items[len(self)] = item

0.37 Points

• self.items +=1

• self.len = self.items

• self = self + 1

• self.size += 1

8)

The code for the __iter__ method is shown below. What is the missing code?

def __iter__(self):

while cursor < len(self):

yield self.items[cursor]

cursor += 1

0.37 Points

• cursor = len(self)

• cursor = self.size

• cursor = 1

• cursor = 0

9)

What method does Python run when it sees the in operator used with a collection?

0.37 Points

• _iter_

• _eq_

• _add_

• _contains_

10)

The __eq__ method in the AbstractCollection class compares pairs of items in two collections.

0.37 Points

• True

• False

11)

A primary purpose of using inheritance is to eliminate redundant code.

0.37 Points

• True

• False

12)

Programming languages such as Java include a collection framework more extensive than that of Python.

0.37 Points

• True

• False

13)

When a programmer calls the iter function on a collection, the collection's iterator object is returned.

0.37 Points

• True

• False

14)

If a programmer calls the next function on an iterator object and there is no current item in the sequence, the next function returns the Null item.

0.37 Points

• True

• False

15)

In the case of the AbstractCollection class, which of the following methods should NOT be included in this class?

0.38 Points

• count

• add

• isEmpty

• _len_

16)

When creating the AbstractCollection class, which methods must you modify to provide default behavior?

0.38 Points

• _init_ and _len_

• isEmpty and add

• _len_ and count

• _str_ and _eq_

17)

When a programmer calls the next function on an iterator object, what happens if there is no current item in the sequence?

0.38 Points

• the None item is returned

• the compiler generates an error

• a StopIteration exception is raised

• the previous item is returned

18)

In the following code for the ArrayBag class __contains__ method, what is the missing code?

def __contains__(self, item):

left = 0

right = len(self) - 1

while left <= right:

midPoint = (left + right) // 2

if self.items[midPoint] == item:

return True

elif self.items[midPoint] > item:

right = midPoint - 1

else:

return False

0.38 Points

• right = midPoint + 1

• left = midPoint + 1

• right = left + 1

• left = midPoint - 1

19)

In the following code for the __add__ method in the ArraySortedBag class, what is the missing code?

def __add__(self, other):

result = ArraySortedBag(self)

for item in other:

return result

0.38 Points

• result.add(item)

• add.item(result)

• result = result + 1

• item.add(result)

20)

Access to a stack is restricted to the bottom end.

0.38 Points

• True

• False

21)

Stacks adhere to a LIFO protocol.

0.38 Points

• True

• False

22)

The operation for removing an item from the stack is called push.

0.38 Points

• True

• False

23)

With a stack, you always access the item that has been most recently added.

0.38 Points

• True

• False

24)

The operator in a postfix expression follows the operands.

0.38 Points

• True

• False

25)

The operator in an infix expression follows the operands.

0.38 Points

• True

• False

26)

A stack structure is a built-in part of the Python language.

0.38 Points

• True

• False

27)

A stack structure is a built-in part of the Python language.

0.38 Points

• True

• False

28)

When using a stack to evaluate the balance of brackets and parentheses in an expression, what is the final step?

0.38 Points

• at the end of the expression, if a final closing bracket is found, the brackets balance

• at the end of the expression, if the stack is full, the brackets balance

• at the end of the expression, if the stack is empty, the brackets do not balance

• at the end of the expression, if the stack is empty, the brackets balance

29)

What is the function of the peek method in a stack implementation?

0.38 Points

• to return the top item and remove it from the stack

• to return the top item without removing it

• to return the bottom item without removing it

• to return the bottom item and remove it from the stack

30)

In the algorithm to evaluate a postfix expression, what does the algorithm do when an operator is encountered?

0.38 Points

• pop the resulting value from the stack

• push the preceding operands onto the stack

• push the operator onto the stack

• apply the operator to the two preceding operands

31)

If the portion of the postfix expression scanned so far is 7 6 2 +, what is the result when the operator is applied to the operands?

0.38 Points

• 13

• 9

• 8

• 15

32)

What is the resulting postfix expression from the following infix expression? (12 + 5) * 2 - 3

0.38 Points

• 12 5 2 + * 3 -

• 12 5 2 + 3 - *

• 12 5 + 2 3 * -

• 12 5 + 2 * 3 -

33)

Which of the following begins in a predefined starting state and then moves from state to state in search of a desired ending state?

0.38 Points

• memory management algorithm

• postfix to infix converter

• infix to postfix converter

• backtracking algorithm

34)

In the following code that defines the push method for the array-based stack, what is the missing code?

def push (self, item):

self.size += 1

0.38 Points

• items[size] = len(self.item)

• item = self.items[self.size + 1]

• self.items[len(self)] = item

• self.items += 1

35)

In the linked implementation of a stack, what type of helper function simplifies the __iter__ method?

0.38 Points

• random

• binary

• recursive

• sequential

Saved

36)

Queues are linear collections.

0.38 Points

• True

• False

Saved

37)

A checkout line at a grocery store is an example of a queue.

0.38 Points

• True

• False

38)

In a priority queue, items waiting in the queue the longest are always popped next.

0.38 Points

• True

• False

39)

The list data structure in Python cannot be used to emulate a queue because there is no pop method.

0.38 Points

• True

• False

40)

Performing a pop operation on an empty queue throws an exception.

0.38 Points

• True

• False

41)

Simulation programs can use a range of integer values to mimic variability in the simulation.

0.38 Points

• True

• False

42)

The ready queue contains processes waiting to use the CPU.

0.38 Points

• True

• False

43)

What happens to processes on the ready queue in a round-robin CPU scheduling scheme?

0.38 Points

• they are pushed and put in the priority queue

• they are pushed to the end of the queue

• they are popped and allocated memory

• they are popped and given a slice of CPU time

44)

In a linked implementation of a queue, what does the add operation do?

0.38 Points

• adds a node to the tail

• inserts a node in the middle

• adds a node to the head

• creates a new instance of the queue

45)

In the following code for the add method for a linked queue implementation, what is the missing code?

def add(self, newItem):

newNode = Node(newItem, None)

if self.isEmpty():

self.front = newNode

else:

self.rear.next = newNode

self.size += 1

0.38 Points

• self.rear = newNode

• self.rear -= 1

• self.front = self.next

• self.rear.prev = None

46)

What is the solution to achieving good performance for both the add and pop methods in the array implementation of a queue?

0.38 Points

• using an insert function instead of add

• using a front pointer that advanced through the array

• using a circular array implementation

• using a fixed front pointer to index position 0

47)

What can you do if items in a priority queue cannot use the comparison operators?

0.38 Points

• remove them in FIFO order

• put them in the back of the queue

• user a wrapper class

• remove them from the queue

48)

In the following code for the __eq__ method for the Comparable class, what is the missing code?

def __eq__(self, other):

if self is other: return True

if type(self) != type(other):

return self.priority == other.priority

0.38 Points

• return False

• return self.priority

• return type(other)

• return other

49)

In the linked priority queue, what is the time and space analysis for the add method?

0.38 Points

• O(n2)

• O(n)

• exponential

• logarithmic