User perform following operations on stack of size 5 then -push(1);pop();push(2);push(3);pop();push(2);pop();pop();push(4);pop();pop();push(5);Which of the following is correct statement for stack ?

Stack Operations will be performed Smoothly

Adding element to stack means ___________.

Placing element at the front end

Placing element at the rear end

Placing element at the front end

Pushing element in the stack means _____________.

Removing element from the stack

Which of the following types of expressions does not require precedence rule when evaluated?

Full parenthesized infix expression

Partially parenthesized infix expression

n elements of a Queue are to be reversed using another queue. The number of “ADD” and “REMOVE” operations required to do so is:

The task cannot be accomplished

161 + Mcqs in Stacks and Queues in Data Structures and Algorithms Page 3 McqOptions

101.	Evaluate Postfix expression from given infix expression.A + B * (C + D) / F + D * E
A.	AB+CDF/+DE
B.	ABCD+F/+DE+
C.	ABCD+/F+DE
D.	AB+CDF/+DE
Answer» C. ABCD+/F+DE

Discussion

102.	Jan Lukasiewicz, who suggested two alternative notations to represent an arithmetic expression belonged to which nationality?
A.	English
B.	Polish
C.	German
D.	Swedish
Answer» C. German

Discussion

103.	What will be the postfix expression for following infix expression:b * c + d / e
A.	b*cde/+
B.	bcd*e/+
C.	bc*de/+
D.	bc*de+/
Answer» D. bc*de+/

Discussion

104.	If memory for the run-time stack is only 150 cells(words), how big can N be in Factorial(N) before encounterring stack overflow?
A.	13
B.	26
C.	31
D.	45
Answer» C. 31

Discussion

105.	Data Structure required to evaluate infix to postfix is __________.
A.	Pointer
B.	Heap
C.	Stack
D.	Queue
Answer» D. Queue

Discussion

106.	Which of the following is an application of stack?
A.	finding factorial
B.	tower of Hanoi
C.	infix to postfix conversion
D.	all of the above
Answer» E.

Discussion

107.	What will be the postfix expression for following infix expression - A + B * C ^ D
A.	ABCD*+^
B.	ABC+D*^
C.	ABCD+*^
D.	ABCD^*+
Answer» E.

Discussion

108.	A ……. is a data structure that organizes data similar to a line in the supermarket, where the first one in line is the first one out.
A.	Queue linked list
B.	Stacks linked list
C.	Both of them
D.	Neither of them
Answer» B. Stacks linked list

Discussion

109.	……………. Is a pile in which items are added at one end and removed from the other.
A.	Stack
B.	Queue
C.	List
D.	None of the above
Answer» C. List

Discussion

110.	What is the postfix form of the following prefix expression -A/B*C$DE
A.	A-BCDE$*/
B.	ABC$ED*/-
C.	ABCDE$*/-
D.	A-BCDE$*/-
Answer» D. A-BCDE$*/-

Discussion

111.	In a computer system, when an __________ expression in an infix notation needs to be evaluated, it is first converted into its postfix notation?
A.	Algebraic
B.	Arithmetic
C.	Trigonometric
D.	Geometric
Answer» C. Trigonometric

Discussion

112.	Identify the data structure which allows deletions at both ends of the list but insertion at only one end.
A.	Input restricted dequeue
B.	Output restricted qequeue
C.	Priority queues
D.	Stack
Answer» B. Output restricted qequeue

Discussion

113.	In conversion from prefix to postfix using stack data-structure, if operators and operands are pushed and popped exactly once, then the run-time complexity is ............
A.	Ο(1)
B.	Ο(n)
C.	Ο(log n)
D.	Ο(n^2)
Answer» C. Ο(log n)

Discussion

114.	………… is not the operation that can be performed on queue.
A.	Insertion
B.	Deletion
C.	Retrieval
D.	Traversal
Answer» E.

Discussion

115.	Which of the following data structure may give overflow error,even though the current number of element in it is less than its size?
A.	Simple queue
B.	Circular queue
C.	Priority Queues
D.	None of these
Answer» C. Priority Queues

Discussion

116.	User perform following operations on stack of size 5 then -push(1);pop();push(2);push(3);pop();push(2);pop();pop();push(4);pop();pop();push(5);Which of the following is correct statement for stack ?
A.	Stack Operations will be performed Smoothly
B.	Underflow Occures
C.	Overflow Occures
D.	None of these
Answer» C. Overflow Occures

Discussion

117.	Select the appropriate code which reverses a word.
A.	a
B.	b
C.	c
D.	d
Answer» C. c

Discussion

118.	Select the appropriate code which tests for a palindrome.
A.	a
B.	b
C.	c
D.	d
Answer» B. b

Discussion

119.	Select the appropriate code for the recursive Tower of Hanoi problem.(n is the number of disks)
A.	a
B.	b
C.	c
D.	d
Answer» B. b

Discussion

120.	Write a piece of code which returns true if the string contains balanced parenthesis, false otherwise.
A.	a
B.	b
C.	c
D.	d
Answer» B. b

Discussion

121.	For every matching parenthesis, print their indices.
A.	a
B.	b
C.	c
D.	d
Answer» B. b

Discussion

122.	In Computer generally _________ expressions are preferred.
A.	Postfix
B.	Infix
C.	Prefix
D.	None of the above
Answer» D. None of the above

Discussion

123.	The total number of elements in a stack at a given point of time can be calculated from the value of______.
A.	Overflow
B.	Top
C.	Queues
D.	Underflow
Answer» C. Queues

Discussion

124.	Adding element to stack means ___________.
A.	Placing element at the rear end
B.	Placing element at the top
C.	Placing element at the front end
D.	None of these
Answer» C. Placing element at the front end

Discussion

125.	In the stack, If user try to remove element from the empty stack then it called as ___________.
A.	Empty Collection
B.	Underflow of Stack
C.	Garbage Collection
D.	Overflow of Stack
Answer» C. Garbage Collection

Discussion

126.	The prefix of (A+B)(C-D)/EF is:
A.	/+-AB*CD
B.	/+-ABCDEF
C.	/+AB-CDEF
D.	**AB+CD/EF
Answer» D. **AB+CD/EF

Discussion

127.	Post fix form ofA + (B * C)is -
A.	AB * C +
B.	ABC * +
C.	AB + C *
D.	ABC + *
Answer» C. AB + C *

Discussion

128.	Which of the following statement is true?i) Using singly linked lists and circular list, it is not possible to traverse the list backwards.ii) To find the predecessor, it is required to traverse the list from the first node in case of singly linked list.
A.	i-only
B.	ii-only
C.	Both i and ii
D.	None of the above
Answer» D. None of the above

Discussion

129.	Queue can be used to implement
A.	recursion
B.	radix sort
C.	quick sort
D.	depth first search
Answer» C. quick sort

Discussion

130.	The prefix form of an infix expression A+B-C*D is
A.	+AB-*CD
B.	-+A B C * D
C.	-+A B * C D
D.	- + *ABCD
Answer» D. - + *ABCD

Discussion

131.	Inserting an item into the stack when stack is not full is called …………. Operation and deletion of item form the stack, when stack is not empty is called ………..operation.
A.	push, pop
B.	pop, push
C.	insert, delete
D.	delete, insert
Answer» B. pop, push

Discussion

132.	A stack works on the principle of____________.
A.	LIFO
B.	LAFO
C.	LIFF
D.	None of the above
Answer» B. LAFO

Discussion

133.	Pushing element in the stack means _____________.
A.	Sorting element from the stack
B.	Adding element in the stack
C.	Removing element from the stack
D.	Searching element in the stack
Answer» C. Removing element from the stack

Discussion

134.	User perform following operations on stack of size 5 then -push(1);pop();push(2);push(3);pop();push(4);pop();pop();push(5);at the end of last operation, total number of elements present in the stack are -
A.	3
B.	4
C.	2
D.	1
Answer» E.

Discussion

135.	Which of the following types of expressions does not require precedence rule when evaluated?
A.	Prefix expression
B.	More than one of these
C.	Full parenthesized infix expression
D.	Partially parenthesized infix expression
Answer» C. Full parenthesized infix expression

Discussion

136.	Consider following Scenario -1. The five items : P,Q,R,S and T are inserted into stack A one after other starting from T in reverse order.2. The stack is popped three times and each element is inserted into another stack B.3. Then two elements are deleted from the stack B and pushed back onto the stack A.What are the topmost elements of stack A and Stack B respectively?
A.	R P
B.	R Q
C.	Q R
D.	Q P
Answer» E.

Discussion

137.	Using Pop(S1, Item) Push(S1,Item) Read(Item) Print(Item) the variables S1 represents (stack) and Item are given the input file: A,B,C,D,E,F Which stacks are possible:
A.	54 3 F2 D1 B
B.	5 4 3 D2 A1 F
C.	543 C2 E1 B
D.	5 A4 B3 C2 D1 E
Answer» B. 5 4 3 D2 A1 F

Discussion

138.	Queue data structure works on
A.	LIFO
B.	FIFO
C.	FILO
D.	none of the above
Answer» C. FILO

Discussion

139.	The result of evaluating the following postfix expression is5, 7, 9, *, +, 4, 9, 3, /, +, -
A.	50
B.	65
C.	61
D.	70
Answer» D. 70

Discussion

140.	Which data structure allows deleting data elements from front and inserting at rear?
A.	Stacks
B.	Queues
C.	Deques
D.	Binary search tree
Answer» C. Deques

Discussion

141.	Stack can be implemented using ___________ and _________.
A.	Array and Linked List
B.	Queue and Graphs
C.	Trees and Linked List
D.	Array and Graphs
Answer» B. Queue and Graphs

Discussion

142.	The data structure required to evaluate a postfix expression is
A.	queue
B.	stack
C.	array
D.	linked-list
Answer» C. array

Discussion

143.	Post fix form of following infix expression is - * + A B - C D
A.	ABCD + - *
B.	AB + CD - *
C.	AB + CD * -
D.	AB + C - D *
Answer» C. AB + CD * -

Discussion

144.	n elements of a Queue are to be reversed using another queue. The number of “ADD” and “REMOVE” operations required to do so is:
A.	2*n
B.	4*n
C.	n
D.	The task cannot be accomplished
Answer» E.

Discussion

145.	Stack A has 3 Elements in it Say X,Y and Z with X on top.1. Stack B is empty.2. An Element popped out from Stack A can be printed immediately or pushed to stack B.3. An Element popped out from Stack B can only be printed.In this arrangement, which of the following permutations of X,Y,Z are not possible ?
A.	Y X Z
B.	Z X Y
C.	Y Z X
D.	Z Y X
Answer» C. Y Z X

Discussion

146.	One can convert an infix expression to a postfix expression using a ..............
A.	Stack
B.	Queue
C.	Deque
D.	None of these
Answer» B. Queue

Discussion

147.	In C programming, when we remove an item from bottom of the stack, then −
A.	The stack will fall down.
B.	Stack will rearranged items.
C.	It will convert to LIFO
D.	This operation is not allowed.
Answer» C. It will convert to LIFO

Discussion

148.	Stack is useful for implemeting
A.	recursion
B.	depth first search
C.	both (a) and (b)
D.	breadth first search
Answer» D. breadth first search

Discussion

149.	A data structure where elements can be added or removed at either end but not in the middle is called …
A.	linked lists
B.	stacks
C.	queues
D.	dequeue
Answer» E.

Discussion

150.	Consider these functions:push() : push an element into the stackpop() : pop the top-of-the-stack elementtop() : returns the item stored in top-of-the-stack-nodeWhat will be the output after performing these sequence of operationspush(20);push(4);top();pop();pop();pop();push(5);top();
A.	20
B.	4
C.	stack underflow
D.	5
Answer» E.

Discussion

Explore topic-wise MCQs in Data Structures and Algorithms.

Evaluate Postfix expression from given infix expression.A + B * (C + D) / F + D * E

Jan Lukasiewicz, who suggested two alternative notations to represent an arithmetic expression belonged to which nationality?

What will be the postfix expression for following infix expression:b * c + d / e

If memory for the run-time stack is only 150 cells(words), how big can N be in Factorial(N) before encounterring stack overflow?

Data Structure required to evaluate infix to postfix is __________.

Which of the following is an application of stack?

What will be the postfix expression for following infix expression - A + B * C ^ D

A ……. is a data structure that organizes data similar to a line in the supermarket, where the first one in line is the first one out.

……………. Is a pile in which items are added at one end and removed from the other.

What is the postfix form of the following prefix expression -A/B*C$DE

In a computer system, when an __________ expression in an infix notation needs to be evaluated, it is first converted into its postfix notation?

Identify the data structure which allows deletions at both ends of the list but insertion at only one end.

In conversion from prefix to postfix using stack data-structure, if operators and operands are pushed and popped exactly once, then the run-time complexity is ............

………… is not the operation that can be performed on queue.

Which of the following data structure may give overflow error,even though the current number of element in it is less than its size?

User perform following operations on stack of size 5 then -push(1);pop();push(2);push(3);pop();push(2);pop();pop();push(4);pop();pop();push(5);Which of the following is correct statement for stack ?

Select the appropriate code which reverses a word.

Select the appropriate code which tests for a palindrome.

Select the appropriate code for the recursive Tower of Hanoi problem.(n is the number of disks)

Write a piece of code which returns true if the string contains balanced parenthesis, false otherwise.

For every matching parenthesis, print their indices.

In Computer generally _________ expressions are preferred.

The total number of elements in a stack at a given point of time can be calculated from the value of______.

Adding element to stack means ___________.

In the stack, If user try to remove element from the empty stack then it called as ___________.

The prefix of (A+B)*(C-D)/E*F is:

Post fix form ofA + (B * C)is -

Which of the following statement is true?i) Using singly linked lists and circular list, it is not possible to traverse the list backwards.ii) To find the predecessor, it is required to traverse the list from the first node in case of singly linked list.

Queue can be used to implement

The prefix form of an infix expression A+B-C*D is

Inserting an item into the stack when stack is not full is called …………. Operation and deletion of item form the stack, when stack is not empty is called ………..operation.

A stack works on the principle of____________.

Pushing element in the stack means _____________.

User perform following operations on stack of size 5 then -push(1);pop();push(2);push(3);pop();push(4);pop();pop();push(5);at the end of last operation, total number of elements present in the stack are -

Which of the following types of expressions does not require precedence rule when evaluated?

Using Pop(S1, Item) Push(S1,Item) Read(Item) Print(Item) the variables S1 represents (stack) and Item are given the input file: A,B,C,D,E,F Which stacks are possible:

Queue data structure works on

The result of evaluating the following postfix expression is5, 7, 9, *, +, 4, 9, 3, /, +, -

Which data structure allows deleting data elements from front and inserting at rear?

Stack can be implemented using ___________ and _________.

The data structure required to evaluate a postfix expression is

Post fix form of following infix expression is - * + A B - C D

n elements of a Queue are to be reversed using another queue. The number of “ADD” and “REMOVE” operations required to do so is:

One can convert an infix expression to a postfix expression using a ..............

In C programming, when we remove an item from bottom of the stack, then −

Stack is useful for implemeting

A data structure where elements can be added or removed at either end but not in the middle is called …

Consider these functions:push() : push an element into the stackpop() : pop the top-of-the-stack elementtop() : returns the item stored in top-of-the-stack-nodeWhat will be the output after performing these sequence of operationspush(20);push(4);top();pop();pop();pop();push(5);top();

The prefix of (A+B)(C-D)/EF is:

Stack can be implemented using ___ and _.