Question 1

The equation 17 46 + is an example of postfix form.

Accepted Answer

A) True 
 B)False  True

Question 2

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

Accepted Answer

A)  self.items += 1 
B)  self.items[ len(self) ] = item 
C)  items[ size ] = len(self.item) 
D)  item = self.items[ self.size + 1 ] 
A)  self.items += 1 
B)  self.items[ len(self) ] = item 
C)  items[ size ] = len(self.item) 
D)  item = self.items[ self.size + 1 ] B

Question 3

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

Accepted Answer

A) True 
 B)False  False

Question 4

A token in the postfix expression evaluation algorithm is an operand or operator.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following is NOT an example of a stack in everyday life?

Accepted Answer

A)  a spindle of blank DVDs 
B)  a stack of plates in a cafeteria line 
C)  a pile of napkins 
D)  a jar of jellybeans 
A)  a spindle of blank DVDs 
B)  a stack of plates in a cafeteria line 
C)  a pile of napkins 
D)  a jar of jellybeans

Question 6

The operator in an infix expression follows the operands.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following is true about a postfix expression?

Accepted Answer

A)  the operator is between its two operands 
B)  the operator follows its two operands 
C)  stack of bricks 
D)  table of contents 
A)  the operator is between its two operands 
B)  the operator follows its two operands 
C)  stack of bricks 
D)  table of contents

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

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

Accepted Answer

A)  backtracking algorithm 
B)  memory management algorithm 
C)  infix to postfix converter 
D)  postfix to infix converter 
A)  backtracking algorithm 
B)  memory management algorithm 
C)  infix to postfix converter 
D)  postfix to infix converter

Question 10

What is the function of the PVM?

Accepted Answer

A)  converts methods to subroutines 
B)  executes a python program from bytecodes 
C)  compiles Python code into assembly language 
D)  links a Python program to imported modules 
A)  converts methods to subroutines 
B)  executes a python program from bytecodes 
C)  compiles Python code into assembly language 
D)  links a Python program to imported modules

Question 11

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

Accepted Answer

A)  push opening brackets onto the stack while scanning the expression 
B)  pop closing brackets onto the stack while scanning the expression 
C)  push closing brackets onto the stack while scanning the expression 
D)  pop opening brackets onto the stack while scanning the expression 
A)  push opening brackets onto the stack while scanning the expression 
B)  pop closing brackets onto the stack while scanning the expression 
C)  push closing brackets onto the stack while scanning the expression 
D)  pop opening brackets onto the stack while scanning the expression

Question 12

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

Accepted Answer

A)  12 5 2 + * 3 - 
B)  12 5 + 2 3 * - 
C)  12 5 + 2 * 3 - 
D)  12 5 2 + 3 - * 
A)  12 5 2 + * 3 - 
B)  12 5 + 2 3 * - 
C)  12 5 + 2 * 3 - 
D)  12 5 2 + 3 - *

Question 13

What is the resulting infix expression from the following postfix expression? 17 4 - 6 + 8 *

Accepted Answer

A)  17 - (4 + 6 * 8) 
B)  17 - (4 + 6) * 8 
C)  (17 - 4) + (6 * 8) 
D)  (17 - 4 + 6) * 8 
A)  17 - (4 + 6 * 8) 
B)  17 - (4 + 6) * 8 
C)  (17 - 4) + (6 * 8) 
D)  (17 - 4 + 6) * 8

Question 14

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

Accepted Answer

A)  binary 
B)  sequential 
C)  recursive 
D)  random 
A)  binary 
B)  sequential 
C)  recursive 
D)  random

Question 15

If the current state of the stack is [ x, y, z ] where x is the bottom of the stack and z is the top of the stack, what is the state of the stack and the value returned after a pop operation?

Accepted Answer

A)  the state is [ x, y ]; z is returned 
B)  the state is [ x, y, z ]; z is returned 
C)  the state is [ y, z ]; x is returned 
D)  the state is [ x, y, z ]; x is returned 
A)  the state is [ x, y ]; z is returned 
B)  the state is [ x, y, z ]; z is returned 
C)  the state is [ y, z ]; x is returned 
D)  the state is [ x, y, z ]; x is returned

Question 16

If the entire postfix expression is 9 1 4 + - 2 *, what is the final value?

Accepted Answer

A)  12 
B)  8 
C)  17 
D)  10 
A)  12 
B)  8 
C)  17 
D)  10

Question 17

In what way doesn't the Python list data structure accurately emulate a stack?

Accepted Answer

A)  the append method pushes elements onto the stack 
B)  the pop method removes and returns the top element 
C)  a list uses an array as the underlying data structure 
D)  list methods allow manipulation of items at any position 
A)  the append method pushes elements onto the stack 
B)  the pop method removes and returns the top element 
C)  a list uses an array as the underlying data structure 
D)  list methods allow manipulation of items at any position

Question 18

The push operation for a stack raises an error if the stack is empty.

Accepted Answer

A) True 
 B)False

Question 19

Stacks adhere to a LIFO protocol.

Accepted Answer

A) True 
 B)False

Question 20

Access to a stack is restricted to the bottom end.

Accepted Answer

A) True 
 B)False

The equation 17 46 + is an example of postfix form.

In the following code that defines the push method for the array-based stack, what is the missing code? def push (self, item): < missing code > Self.size += 1

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

A token in the postfix expression evaluation algorithm is an operand or operator.

Which of the following is NOT an example of a stack in everyday life?

The operator in an infix expression follows the operands.

Which of the following is true about a postfix expression?

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

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

What is the function of the PVM?

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

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

What is the resulting infix expression from the following postfix expression? 17 4 - 6 + 8 *

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

If the current state of the stack is [ x, y, z ] where x is the bottom of the stack and z is the top of the stack, what is the state of the stack and the value returned after a pop operation?

If the entire postfix expression is 9 1 4 + - 2 *, what is the final value?

In what way doesn't the Python list data structure accurately emulate a stack?

The push operation for a stack raises an error if the stack is empty.

Stacks adhere to a LIFO protocol.

Access to a stack is restricted to the bottom end.

Basic Python Programming

An Overview of Collections

Searching, Sorting, and Complexity Analysis

Arrays and Linked Structures

Interfaces, Implementations, and Polymorphism

Inheritance and Abstract Classes

Queues

Lists

Trees

Sets and Dictionaries

Graphs

Filters

Exam 7: Stacks

The equation 17 46 + is an example of postfix form.

In the following code that defines the push method for the array-based stack, what is the missing code? def push (self, item): < missing code > Self.size += 1

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

A token in the postfix expression evaluation algorithm is an operand or operator.

Which of the following is NOT an example of a stack in everyday life?

The operator in an infix expression follows the operands.

Which of the following is true about a postfix expression?

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

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

What is the function of the PVM?

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

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

What is the resulting infix expression from the following postfix expression? 17 4 - 6 + 8 *

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

If the current state of the stack is [ x, y, z ] where x is the bottom of the stack and z is the top of the stack, what is the state of the stack and the value returned after a pop operation?

If the entire postfix expression is 9 1 4 + - 2 *, what is the final value?

In what way doesn't the Python list data structure accurately emulate a stack?

The push operation for a stack raises an error if the stack is empty.

Stacks adhere to a LIFO protocol.

Access to a stack is restricted to the bottom end.

Basic Python Programming

An Overview of Collections

Searching, Sorting, and Complexity Analysis

Arrays and Linked Structures

Interfaces, Implementations, and Polymorphism

Inheritance and Abstract Classes

Queues

Lists

Trees

Sets and Dictionaries

Graphs

Filters

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