550+ Data Structures (DS) Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Computer Science Engineering (CSE) , Information Technology Engineering (IT) , Bachelor of Science in Computer Science FY (BSc CS) , Bachelor of Science in Information Technology FY (BSc IT) , Bachelor of Computer Applications (BCA) .

Chapters

Take a Test

301.	A linear list in which each node has pointers to point to the predecessor and successors nodes is called as
A.	singly linked list
B.	circular linked list
C.	doubly linked list
D.	linear linked list
Answer» C. doubly linked list

302.	The situation when in a linked list START=NULL is
A.	underflow
B.	overflow
C.	housefull
D.	saturated
Answer» A. underflow

303.	In doubly linked lists, traversal can be performed?
A.	only in forward direction
B.	only in reverse direction
C.	in both directions
D.	none of the above
Answer» C. in both directions

304.	How do you count the number of elements in the circular linked list?
A.	public int length(node head) { int length = 0; if( head == null) return 0; node temp = head.getnext(); while(temp != head) { temp = temp.getnext(); length++; } return length; }
B.	public int length(node head) { int length = 0; if( head == null) return 0; node temp = head.getnext(); while(temp != null) { temp = temp.getnext(); length++; } return length; }
C.	public int length(node head) { int length = 0; if( head == null) return 0; node temp = head.getnext(); while(temp != head && temp != null) { temp = head.getnext(); length++; } return length; }
D.	public int length(node head) { int length = 0; if( head == null) return 0; node temp = head.getnext(); while(temp != head && temp == null) { temp = head.getnext(); length++; } return length; }
Answer» A. public int length(node head) { int length = 0; if( head == null) return 0; node temp = head.getnext(); while(temp != head) { temp = temp.getnext(); length++; } return length; }

305.	public int function() { if(head == null) return Integer.MIN_VALUE; int var; Node temp = head; while(temp.getNext() != head) temp = temp.getNext(); if(temp == head) { var = head.getItem(); head = null; return var; } temp.setNext(head.getNext()); var = head.getItem(); head = head.getNext(); return var; } What is the functionality of the following code? Choose the most appropriate answer.
A.	return data from the end of the list
B.	returns the data and deletes the node at the end of the list
C.	returns the data from the beginning of the list
D.	returns the data and deletes the node from the beginning of the list
Answer» D. returns the data and deletes the node from the beginning of the list

306.	What is the functionality of the following code? Choose the most appropriate answer. public int function() { if(head == null) return Integer.MIN_VALUE; int var; Node temp = head; Node cur; while(temp.getNext() != head) { cur = temp; temp = temp.getNext(); } if(temp == head) { var = head.getItem(); head = null; return var; } var = temp.getItem(); cur.setNext(head); return var; }
A.	return data from the end of the list
B.	returns the data and deletes the node at the end of the list
C.	returns the data from the beginning of the list
D.	returns the data and deletes the node from the beginning of the list
Answer» B. returns the data and deletes the node at the end of the list

307.	How do you insert a node at the beginning of the list?
A.	public class insertfront(int data) { node node = new node(data, head, head.getnext()); node.getnext().setprev(node); head.setnext(node); size++; }
B.	public class insertfront(int data) { node node = new node(data, head, head); node.getnext().setprev(node); head.setnext(node); size++; }
C.	public class insertfront(int data) { node node = new node(data, head, head.getnext()); node.getnext().setprev(head); head.setnext(node); size++; }
D.	public class insertfront(int data) { node node = new node(data, head, head.getnext()); node.getnext().setprev(node); head.setnext(node.getnext()); size++; }
Answer» A. public class insertfront(int data) { node node = new node(data, head, head.getnext()); node.getnext().setprev(node); head.setnext(node); size++; }

308.	What is a dequeue?
A.	a queue with insert/delete defined for both front and rear ends of the queue
B.	a queue implemented with a doubly linked list
C.	a queue implemented with both singly and doubly linked lists
D.	a queue with insert/delete defined for front side of the queue
Answer» A. a queue with insert/delete defined for both front and rear ends of the queue

309.	Suppose a circular queue of capacity (n – 1) elements is implemented with an array of n elements. Assume that the insertion and deletion operation are carried out using REAR and FRONT as array index variables, respectively. Initially, REAR = FRONT = 0. The conditions to detect queue full and queue empty are
A.	full: (rear+1) mod n == front, empty: rear == front
B.	full: (rear+1) mod n == front, empty: (front+1) mod n == rear
C.	full: rear == front, empty: (rear+1) mod n == front
D.	full: (front+1) mod n == rear, empty: rear == front
Answer» A. full: (rear+1) mod n == front, empty: rear == front

310.	Suppose implementation supports an instruction REVERSE, which reverses the order of elements on the stack, in addition to the PUSH and POP instructions. Which one of the following statements is TRUE with respect to this modified stack?
A.	a queue cannot be implemented using this stack.
B.	a queue can be implemented where enqueue takes a single instruction and dequeue takes a sequence of two instructions.
C.	a queue can be implemented where enqueue takes a sequence of three instructions and dequeue takes a single instruction.
D.	a queue can be implemented where both enqueue and dequeue take a single instruction each.
Answer» C. a queue can be implemented where enqueue takes a sequence of three instructions and dequeue takes a single instruction.

311.	Suppose you are given an implementation of a queue of integers. The operations that can be performed on the queue are: i. isEmpty (Q) — returns true if the queue is empty, false otherwise. ii. delete (Q) — deletes the element at the front of the queue and returns its value. iii. insert (Q, i) — inserts the integer i at the rear of the queue. Consider the following function: void f (queue Q) { int i ; if (!isEmpty(Q)) { i = delete(Q); f(Q); insert(Q, i); } }What operation is performed by the above function f ?
A.	leaves the queue q unchanged
B.	reverses the order of the elements in the queue q
C.	deletes the element at the front of the queue q and inserts it at the rear keeping the other elements in the same order
D.	empties the queue q
Answer» B. reverses the order of the elements in the queue q

312.	Consider the following statements:i. First-in-first out types of computations are efficiently supported by STACKS. ii. Implementing LISTS on linked lists is more efficient than implementing LISTS on an array for almost all the basic LIST operations. iii. Implementing QUEUES on a circular array is more efficient than implementing QUEUES on a linear array with two indices. iv. Last-in-first-out type of computations are efficiently supported by QUEUES.Which of the following is correct?
A.	(ii) and (iii) are true
B.	(i) and (ii) are true
C.	(iii) and (iv) are true
D.	(ii) and (iv) are true
Answer» A. (ii) and (iii) are true

313.	Which of the following option is not correct?
A.	if the queue is implemented with a linked list, keeping track of a front pointer, only rear pointer s will change during an insertion into an non-empty queue.
B.	queue data structure can be used to implement least recently used (lru) page fault algorithm and quick short algorithm.
C.	queue data structure can be used to implement quick short algorithm but not least recently used (lru) page fault algorithm.
D.	both (a) and (c)
Answer» C. queue data structure can be used to implement quick short algorithm but not least recently used (lru) page fault algorithm.

314.	Consider a standard Circular Queue 'q' implementation (which has the same condition for Queue Full and Queue Empty) whose size is 11 and the elements of the queue are q[0], q[1], q[2].....,q[10]. The front and rear pointers are initialized to point at q[2] . In which position will the ninth element be added?
A.	q[0]
B.	q[1]
C.	q[9]
D.	q[10]
Answer» A. q[0]

315.	Overflow condition in linked list may occur when attempting to .............
A.	create a node when free space pool is empty
B.	traverse the nodes when free space pool is empty
C.	create a node when linked list is empty
D.	none of these
Answer» A. create a node when free space pool is empty

316.	Which of the following is not a type of Linked List ?
A.	doubly linked list
B.	singly linked list
C.	circular linked list
D.	hybrid linked list
Answer» D. hybrid linked list

317.	Linked list is generally considered as an example of _________ type of memory allocation.
A.	static
B.	dynamic
C.	compile time
D.	none of these
Answer» B. dynamic

318.	Each Node contain minimum two fields one field called data field to store data. Another field is of type _________.
A.	pointer to class
B.	pointer to an integer
C.	pointer to character
D.	pointer to node
Answer» D. pointer to node

319.	If in a linked list address of first node is 1020 then what will be the address of node at 5th position ?
A.	1036
B.	1028
C.	1038
D.	none of these
Answer» D. none of these

320.	In Circular Linked List insertion of a node involves the modification of ____ links.
A.	3
B.	4
C.	1
D.	2
Answer» D. 2

321.	If a list contains no elements it is said to be
A.	hollow
B.	empty
C.	finite
D.	infinite
Answer» B. empty

322.	Linked list uses
A.	random memory allocation
B.	static memory allocation
C.	fixed memory allocation
D.	dynamic memory allocation
Answer» D. dynamic memory allocation

323.	Standard approach for implementation of a list is/are of
A.	1 type
B.	2 type
C.	3 type
D.	4 type
Answer» B. 2 type

324.	First link node of list is accessed from a pointer named
A.	tail
B.	head
C.	terminator
D.	initiator
Answer» B. head

325.	A linked list is made up of a set of objects known as
A.	nodes
B.	arrays
C.	entities
D.	instances
Answer» A. nodes

550+ Data Structures (DS) Solved MCQs

A linear list in which each node has pointers to point to the predecessor and successors nodes is called as

The situation when in a linked list START=NULL is

In doubly linked lists, traversal can be performed?

How do you count the number of elements in the circular linked list?

How do you insert a node at the beginning of the list?

What is a dequeue?

Suppose implementation supports an instruction REVERSE, which reverses the order of elements on the stack, in addition to the PUSH and POP instructions. Which one of the following statements is TRUE with respect to this modified stack?

Which of the following option is not correct?

Overflow condition in linked list may occur when attempting to .............

Which of the following is not a type of Linked List ?

Linked list is generally considered as an example of _________ type of memory allocation.

Each Node contain minimum two fields one field called data field to store data. Another field is of type _________.

If in a linked list address of first node is 1020 then what will be the address of node at 5th position ?

In Circular Linked List insertion of a node involves the modification of ____ links.

If a list contains no elements it is said to be

Linked list uses

Standard approach for implementation of a list is/are of

First link node of list is accessed from a pointer named

A linked list is made up of a set of objects known as

How do you calculate the pointer difference in a memory efficient double linked list?

A ……………….. is a linear list in which insertions and deletions are made to from either end of the structure.

Which of the following name does not relate to stacks?

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

The postfix form of the expression (A + B)∗(C∗D − E)∗F / G is

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

The data structure required to evaluate a postfix expression is

What is the postfix form of the following prefix: *+ab–cd

A queue is a,

In stack terminology, the __________operations are known as push and pop operations respectively.

A common example of a queue is people waiting in line at a__________.

What is one of the common examples of a stack?

When a stack is organized as an array, a variable named Top is used to point to the top element of the stack. Initially, the value of Top is set to_______to indicate an empty stack.

What happens when the stack is full and there is no space for a new element, and an attempt is made to push a new element?

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

When the push operation is performed on stack the value of TOS will be ______

A double linked list contains reference to _____

Data Structure that are created by user as per their requirement are known as

To insert element at start, the previous pointer of newly added node would point to ______

In linked list implementation, a node carries information regarding

Which of the following data structure is linear type?

Stack is ____ type of data structure.

In stack deletion operation is referred as _____

Queue is _____ type of data structure.

Data structre is divided into _____ parts.

326.	How do you calculate the pointer difference in a memory efficient double linked list?
A.	head xor tail
B.	pointer to previous node xor pointer to next node
C.	pointer to previous node – pointer to next node
D.	pointer to next node – pointer to previous node
Answer» B. pointer to previous node xor pointer to next node

327.	A ……………….. is a linear list in which insertions and deletions are made to from either end of the structure.
A.	circular queue
B.	random of queue
C.	priority
D.	dequeue
Answer» D. dequeue

328.	Which of the following name does not relate to stacks?
A.	fifo lists
B.	lifo list
C.	piles
D.	push-down lists
Answer» A. fifo lists

329.	A data structure where elements can be added or removed at either end but not in the middle is called …
A.	arrays
B.	stacks
C.	queues
D.	deque
Answer» D. deque

330.	The postfix form of the expression (A + B)∗(C∗D − E)∗F / G is
A.	ab + cd∗e − fg /∗∗
B.	/ ab + cd ∗ e − f ∗∗g /
C.	ab + cd ∗ e − ∗f ∗ g /
D.	ab + cde ∗ − ∗ f ∗ g /
Answer» A. ab + cd∗e − fg /∗∗

331.	What is the postfix form of the following prefix expression -A/B*C$DE ?
A.	abcde$*/-
B.	a-bcde$*/-
C.	abc$ed*/-
D.	a-bcde$*/
Answer» A. abcde$*/-

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

333.	What is the postfix form of the following prefix: *+ab–cd
A.	ab+cd–*
B.	abc+*–
C.	ab+*cd–
D.	ab+*cd–
Answer» A. ab+cd–*

334.	A queue is a,
A.	fifo (first in first out) list
B.	lifo (last in first out) list
C.	ordered array
D.	linear tree
Answer» A. fifo (first in first out) list

335.	In stack terminology, the __________operations are known as push and pop operations respectively.
A.	delete
B.	insert
C.	both (a) and (b)
D.	none of the above
Answer» C. both (a) and (b)