Deck 18: Stacks and Queues

Question 1

In the array representation of a stack, if a value called stackTop indicates the number of elements in the stack, then stackTop-1 points to the top item of the stack.

Answer 1

True

Question 2

The infix expression
(a + b) * (c - d / e) + f
is equivalent to the postfix expression
ab + cde /-* f +

Answer 2

True

Question 3

You can perform the operation ____ to remove the top element from the stack.

A) dequeue
B) top
C) pop
D) push

Answer 3

C

Question 4

A stack is a(n) ____ data structure.

A) FIFO
B) FILO
C) LIFO
D) LILO

Question 5

The bottom element of the stack is the last element added to the stack.

Question 6

The expression a + b is the same in both infix notation and postfix notation.

Question 7

If you try to add a new item to a full stack, the resulting condition is called an outflow.

Question 8

A queue is a First In First Out data structure.

Question 9

If you try to add a new item to a full stack, the resulting condition is called a(n) ____.

A) override
B) overflow
C) overload
D) underflow

Question 10

In the array representation of a stack, an unlimited number of elements can be pushed onto the stack.

Question 11

A stack can be implemented as either a(n) ____ or a linked structure.

A) map
B) struct
C) queue
D) array

Question 12

The default constructor for the linked implementation of a stack initializes the stack to an empty state when a stack object is declared.

Question 13

When a stack is implemented as an array, the array is empty if the value of stackTop is ____.

A) zero
B) one
C) nonzero
D) equal to the size of the array

Question 14

The ____ element of the stack is the last element added to the stack.

A) top
B) bottom
C) head
D) tail

Question 15

A(n) ____ is a list of homogenous elements in which the addition and deletion of elements occurs only at one end.

A) stack
B) queue
C) array
D) linked list

Question 16

The addition and deletion of elements of a stack occurs only at the ____ of the stack.

A) head
B) bottom
C) top
D) middle

Question 17

Popping an element from an empty stack is called ____.

A) overflow
B) underflow
C) exception
D) overloading

Question 18

You can perform the add operation, called ____, to add an element onto the stack.

A) pop
B) push
C) enqueue
D) dequeue

Question 19

Postfix notation requires the use of parentheses to enforce operator precedence.

Question 20

In the linked implementation of stacks, the memory to store the stack elements is allocated statically.

Question 21

The postfix expression 14 2 5 + = will generate an error, because ____.

A) it contains an illegal operator
B) it does not have enough operands
C) it has too many operators
D) there will be too many elements in the stack when the equal sign is encountered

Question 22

To describe a queuing system, we use the term ____ for the object that provides the service.

A) client
B) server
C) customer
D) provider

Question 23

The postfix expression 5 6 + 4 * 10 5 / - = evaluates to ____.

A) 10
B) 30
C) 42
D) 44

Question 24

What is the output of the following code? stackType stack;
Int x, y;
X = 4;
Y = 2;
Stack.push(6);
Stack.push(x);
Stack.push(x + 1);
Y = stack.top();
Stack.pop();
Stack.push(x + y);
X = stack.top();
Stack.pop();
Cout << "x = " << x << endl;

A) x = 4
B) x = 5
C) x = 6
D) x = 9

Question 25

In evaluating a postfix expression, when an equal sign (=) is encountered, how many elements must the stack contain so that no error is generated?

A) none
B) one
C) two
D) three

Question 26

A technique in which one system models the behavior of another system is called ____.

A) imitation
B) recursion
C) simulation
D) stimulation

Question 27

The elements at the ____________________ of the stack have been in the stack the longest.

Question 28

The postfix expression 2 4 6 * + 15 - 21 7 / + = evaluates to ____.

A) 4
B) 14
C) 24
D) 26

Question 29

In the array representation of a stack, the stack is initialized simply by setting stackTop to ____________________.

Question 30

What is the output of the following code? queueType queue;
Int x, y;
X = 2;
Y = 6;
Queue.addQueue(x);
Queue.addQueue(y);
X = queue.front();
Queue.deleteQueue();
Queue.addQueue(x + 2);
Queue.addQueue(x);
Queue.addQueue(y - 3);
While (!queue.isEmptyQueue())
{
Cout << queue.front() << " ";
Queue.deleteQueue();
}
Cout << endl

A) 6 2 3 3
B) 6 2 4 2
C) 6 3 3 3
D) 6 4 2 3

Question 31

A queue is a data structure in which the elements are ____.

A) added to the rear and deleted from the front
B) added to and deleted from the rear
C) added to and deleted from the front
D) added and deleted in the middle

Question 32

The operation ____________________ reinitializes a stack to an empty state.

Question 33

To describe a queuing system, we use the term ____ for the object receiving the service.

A) client
B) server
C) customer
D) provider

Question 34

The ____________________ constructor is called when a stack object is passed as a (value) parameter to a function.

Question 35

The postfix expression 3 5 + 2 ; 6 - = will generate an error, because it ____.

A) contains an illegal operator
B) does not have enough operands
C) has too many operands
D) has too many operators

Question 36

An array is a(n) ____________________ access data structure.

Question 37

Which of the following is listed in the chapter as a basic operation performed on a queue?

A) push
B) pop
C) isEmptyQueue
D) top

Question 38

What is the output of the following code? queueType queue;
Int x, y;
X = 2;
Y = 3;
Queue.addQueue(x);
Queue.addQueue(y);
X = queue.front();
Queue.deleteQueue();
Queue.addQueue(x + 2);
Queue.addQueue(x);
Queue.addQueue(y - 3);
Y = queue.front();
Queue.deleteQueue();
Cout << "x = " << x << endl;
Cout << "y = " << y << endl;

A) x = 2
Y = 4
B) x = 4
Y = 3
C) x = 2
Y = 3
D) x = 3
Y = 2

Question 39

The following expression (a - b) * (c + d) is equivalent to which of the following postfix expressions?

A) a b c d - + *
B) a b - c d + *
C) a b - + c d *
D) - + * a b c d

Question 40

What is the output of the following code? stackType stack;
Int x, y;
X = 5;
Y = 3;
Stack.push(4);
Stack.push(x);
Stack.push(x + 1);
Y = stack.top();
Stack.pop();
Stack.push(x + y);
X = stack.top();
Stack.pop();
Cout << "x = " << x << endl;
Cout << "y = " << y << endl;

A) x = 5
Y = 6
B) x = 4
Y = 3
C) x = 5
Y = 3
D) x = 11
Y = 6

Question 41

In a queuing system, every customer has a customer number, arrival time, ____________________ time, transaction time, and departure time.

Question 42

When describing a queuing system, we use the term ____________________ to refer to the time it takes to serve a customer.

Question 43

____________________ techniques are used when it is too expensive or dangerous to experiment with real systems.

Question 44

A(n) ____________________ system consists of servers and queues of objects waiting to be served.

Question 45

In a(n) ____________________ array, the first array position immediately follows the last array position.

Question 46

In a queuing system, we use a(n) ____________________ variable to set the status of the server.

Question 47

In ____________________ notation, operators are written after the operands.

Question 48

In a(n) ____________________ simulation, the clock is implemented as a counter, and the passage of, say, one minute can be implemented by incrementing the counter by 1.

Question 49

In the late 1950s, the Australian philosopher and early computer scientist Charles L. Hamblin proposed a scheme in which the operators follow the operands (postfix operators), resulting in ____________________ notation.

Question 50

If the queue is empty, the operation ____________________ terminates the program.