Data Structures and Algorithms - MCQS

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Question: 1

Experimental way of comparing two Algorithms involves

Select one:

A. All of the options

B. Measurement of runtime in same environment (H/w & S/w)

C. Execution with different input sizes

D. Using Implementation details

Correct Answer: All of the options

Question: 2

What will be the list after third iteration in case of insertion sort

            52, 23, 47, 66, 15, 39

Select one:

A. 15, 23, 39, 47, 52, 66

B. 15, 23, 39, 66, 52, 47

C. 23, 47, 52, 66, 15, 39

D. 23, 52, 47, 66, 15, 39

Correct Answer: 23, 47, 52, 66, 15, 39

Question: 3

Time complexity for following pseudo code is

for(i=1;i<=n;i++)

{

      For(j=1;j<=n;j++)

         {

            C[j][j]=0;

            For(k=1;k<=n;k++)

             C[i][j]=c[i][j]+a[i][k]*b[k][j];

           }

}

Select one:

A. O(n)

B. O(n2)

C. O(n1/2)

D. O(n3)

Correct Answer: O(n3)

Question: 4

You have a sorted array with 1023 elements. You use binary search to determine whether number 239 is present in this array or not. How many elements of the array will you compare it with if number 239 is not present in this array?

Select one:

A. 32

B. 0

C. 239

D. 10

Correct Answer: 10

Question: 5

What do the leaves of an expression tree represent?

Select one:

A. All of the options

B. Operand

C. Operator

D. Operation

Correct Answer: Operand

Question: 6

The following operations are performed on a linear queue with maximum capacity to hold 5 integers: add(5), delete(), add(6), add(7), add(8), delete(). How many more integer elements can still be added to this queue?

Select one:

A. 3

B. 1

C. 2

D. 0

Correct Answer: 3

Question: 7

In a binary tree, if any element is at i, then its leftchild is at

Select one:

A. 2*i

B. 2-i

C. 2

D. None of the option

Correct Answer: 2*i

Question: 8

When the pop operation on Stack is leads to an error?

Select one:

A. When the stack is neither empty nor full

B. Only when the stack is empty

C. When there is an overflow in the stack

D. Only when the stack is full

Correct Answer: Only when the stack is empty

Question: 9

Which of the following points is/are true about Linked List data structure when it is compared with array

Select one:

A. It is easy to insert and delete elements in Linked List

B. Random access is not allowed in a typical implementation of Linked Lists

C. All the options

D. The size of array has to be pre-decided, linked lists can change their size any time.

Correct Answer: All the options

Question: 10

Ravi wants to implement an image viewer application to view images. The application will be able to display an image and will also know what its next and previous images are at any given point of time so that the user can view next/previous image by pressing right/left keys on the keyboard. Which data structure is appropriate for Ravi to use?

Select one:

A. Queue

B. Tree

C. Linked list

D. Stack

Correct Answer: Linked list

Question: 11

What is the smallest value of n such that an algorithm whose running time is 100n2 runs faster than an algorithm whose running time is 2n on the same machine?

Select one:

A. 100

B. 2

C. 14

D. 15

Correct Answer: 15

Question: 12

How many pointers are necessarily changed for the insertion in a Linked List?

Select one:

A. Five

B. One

C. Three

D. Two

Correct Answer: Two

Question: 13

The worst and best case performance of finding maximum element in an array of size n is (using brute-force algorithm)

Select one:

A. O(n)

B. O(log n)         

C. O(n log n)      

D. O(1)

Correct Answer: O(n)

Question: 14

The data structure required to check whether an expression contains balanced parenthesis is

Select one:

A. Tree

B. Queue

C. Stack

D. Array

Correct Answer: Stack

Question: 15

What will be the time complexity for this piece of code

int count = 0;

for (int i = 0; i < N; i++)

    for (int j = 0; j < i; j++)

  count++;

Select one:

A. O(nlogn)

B. O(n)

C. O(logn)

D. O(n2)

Correct Answer: O(n2)

Question: 16

Which of the following is NOT a measure for  an Algorithm

Select one:

A. Data Structure

B. Size Complexity

C. Primitive operations

D. Runtime Complexity

Correct Answer: Primitive operations

Question: 17

You need to design a scheduler that to schedule a set of tasks. A number of the tasks need to wait for other previous tasks to complete prior to running themselves. What data structure would be suitable

Select one:

a. Stack

b. none of the options

c. queue

d. linked list

Correct Answer: queue

Question: 18

Ramu is developing a word processing software in which he wants to provide undo feature. The software will maintain all the sequential changes and at any point of time pressing control z will undo the latest change, what data structure should Ramu use for this?

Select one:

A. Queue

B. Array

C. Linked list

D. Stack

Correct Answer: Stack

Question: 19

From where does the insertion and deletion of elements get accomplished in Queues?

Select one:

A. Front & Rear ends respectively

B. Only from Front end

C. Rear & Front ends respectively

D. Only from Rear end

Correct Answer: Front & Rear ends respectively

Question: 20

The post-order traversal of a binary tree is 6 4 45 13 3. Then possible pre-order traversal will be ________

Select one:

A. 45 13 6 5 3

B. 3 13 4 6 45

C. 3 4 6 13 45

D. 45 6 13 3 5

Correct Answer: 3 13 4 6 45