Data structures Objective Questions And Answers : Set-3

Data structres are commanly asked in Technical interviews.Here we have listed some Data structures questions with answers you can study these for your interview.Here You can make bold yourself in data structures.


Data structures Objective Questions And Answers : Set-1

 Data structures Objective Questions And Answers : Set-2

Q. A binary tree of depth “d” is an almost complete binary tree if

(A) Each leaf in the tree is either at level “d” or at level “d–1”

(B) For any node “n” in the tree with a right descendent at level “d” all the left

descendents of “n” that are leaves, are also at level “d”

(C) Both (A) & (B)

(D) None of the above


Q. A linear collection of data elements where the linear node is given by means of pointer is


(A) linked list (B) node list

(C) primitive list (D) None of these


Q. Representation of data structure in memory is known as:

(A) recursive (B) abstract data type

(C) storage structure (D) file structure


Q. If the address of A[1][1] and A[2][1] are 1000 and 1010 respectively and each element

occupies 2 bytes then the array has been stored in _________ order.

(A) row major (B) column major

(C) matix major (D) none of these


Q. An adjacency matrix representation of a graph cannot contain information of :

(A) nodes (B) edges

(C) direction of edges (D) parallel edges


Q. Quick sort is also known as

(A) merge sort (B) heap sort

(C) bubble sort (D) none of these


Q. One of the major drawback of B-Tree is the difficulty of traversing the keys sequentially.

(A) True (B) False


Q. O(N) (linear time) is better than O(1) constant time.

(A) True (B) False


Q. An ADT is defined to be a mathematical model of a user-defined type along with the collection

of all ____________ operations on that model.

(A) Cardinality (B) Assignment

(C) Primitive (D) Structured


Q. An algorithm is made up of two independent time complexities f (n) and g (n). Then the

complexities of the algorithm is in the order of

(A) f(n) x g(n) (B) Max ( f(n),g(n))

(C) Min (f(n),g(n)) (D) f(n) + g(n)


Q. The goal of hashing is to produce a search that takes

(A) O(1) time (B) O(n2 ) time

(C) O(log n ) time (D) O(n log n ) time


Q. The best average behaviour is shown by

(A) Quick Sort (B) Merge Sort

(C) Insertion Sort (D) Heap Sort


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

(A) ab+cd–* (B) abc+*–

(C) ab+*cd– (D) ab+*cd–


Q. A queue is a,

(A) FIFO (First In First Out) list. (B) LIFO (Last In First Out) list.

(C) Ordered array. (D) Linear tree.

Ans. (A)

Q. Which data structure is needed to convert infix notation to postfix notation?

(A) Branch (B) Queue

(C) Tree (D) Stack

Ans. (D)

Q. Which of the following operations is performed more efficiently by doubly linked list than

by singly linked list?

(A) Deleting a node whose location in given

(B) Searching of an unsorted list for a given item

(C) Inverting a node after the node with given location

(D) Traversing a list to process each node

Ans. (A)

Q. The extra key inserted at the end of the array is called a,

(A) End key. (B) Stop key.

(C) Sentinel. (D) Transposition.

Ans. (C)

Q.77 The prefix form of A-B/ (C * D ^ E) is,

(A) -/*^ACBDE (B) -ABCD*^DE

(C) -A/B*C^DE (D) -A/BC*^DE

Ans. (C)

Q. Consider that n elements are to be sorted. What is the worst case time complexity of Bubble


(A) O(1) (B) O(log2n)

(C) O(n) (D) O(n2)

Ans. (D)

Q. A characteristic of the data that binary search uses but the linear search ignores is


(A) Order of the elements of the list.

(B) Length of the list.

(C) Maximum value in list.

(D) Type of elements of the list.

Ans. (A)

Q. In Breadth First Search of Graph, which of the following data structure is used?

(A) Stack. (B) Queue.

(C) Linked List. (D) None of the above.

Ans. (B)

Q. The largest element of an array index is called its

(A) lower bound. (B) range.

(C) upper bound. (D) All of these.

Ans. (C)

Q.What is the result of the following operation

Top (Push (S, X))

(A) X (B) null

(C) S (D) None of these.

Ans. (A)

Q. How many nodes in a tree have no ancestors.

(A) 0 (B) 1

(C) 2 (D) n

Ans. (B)

Q.In order to get the contents of a Binary search tree in ascending order, one has to traverse it in

(A) pre-order. (B) in-order.

(C) post order. (D) not possible.

Ans. (B)

Q. Which of the following sorting algorithm is stable

(A) insertion sort. (B) bubble sort.

(C) quick sort. (D) heap sort.

Ans. (D)

Q. The prefix form of an infix expression p + q − r * t is



(A) + pq − *rt . (B) − +pqr * t .

(C) − +pq * rt . (D) − + * pqrt .

Ans. (C)

Q. Which data structure is used for implementing recursion?

(A) Queue. (B) Stack.

(C) Arrays. (D) List.

Ans. (B)

Q. In binary search, average number of comparison required for searching an element in a list if n

numbers is

(A) log2 n . (B) n / 2 .

(C) n. (D) n – 1.

Ans. (A)

Q. In order to get the information stored in a Binary Search Tree in the descending order, one

should traverse it in which of the following order?

(A) left, root, right (B) root, left, right

(C) right, root, left (D) right, left, root

Ans. (C)

Q. The equivalent prefix expression for the following infix expression (A+B)-(C+D*E)/F*G is

(A) -+AB*/+C*DEFG (B) /-+AB*+C*DEFG

(C) -/+AB*+CDE*FG (D) -+AB*/+CDE*FG

Ans. (A)

Q. The time required to delete a node x from a doubly linked list having n nodes is

(A) O (n) (B) O (log n)

(C) O (1) (D) O (n log n)

Ans. (C)

Q. Ackerman’s function is defined on the non-negative integers as follows

a (m,n) = n+1 if m=0

= a (m-1, 1) if m¹ 0, n=0

= a (m-1, a(m, n-1)) if m¹ 0, n ¹ 0

The value of a (1, 3) is

(A) 4. (B) 5.

(C) 6. (D) 7.

Ans. (B)

Q. The result of evaluating the postfix expression 5, 4, 6, +, *, 4, 9, 3, /, +, * is

(A) 600. (B) 350.

(C) 650. (D) 588.

Ans. (B)

Q. The worst case of quick sort has order

(A) O(n2) (B) O(n)

(C) O (n log2 n) (D) O (log2 n)

Ans. (A)

Q. For an undirected graph G with n vertices and e edges, the sum of the degrees of each vertex is

(A) ne (B) 2n

(C) 2e (D) en

Ans. (C)

Q. The time required to delete a node x from a doubly linked list having n nodes is

(A) O (n) (B) O (log n)

(C) O (1) (D) O (n log n)

Ans. (C)

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6 Responses to Data structures Objective Questions And Answers : Set-3

  1. gourav singh says:


  2. vikash kuamr says:

    Most of the question asked in the aptitude test.. is extremly nice..

  3. suchit says:


  4. vishal says:


  5. manish singh says:

    very very use full of ds objective quation…………..

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