Top MCQs on Data Structures and Algorithms

Question 11

Which of these operators can be used to concatenate two or more String objects?

• +

• +=

• &

• ||

Question 12

What is the complexity to insert an element in a Heap?

• θ(nlogn)

• θ(n)

•  θ(logn)

• θ(1)

Question 13

If the elements “A”, “B”, “C” and “D” are placed in a queue and are deleted one at a time, in what order will they be removed?  

• ABCD

• DCBA

• DCAB

• ABDC

Question 14

Consider an implementation of an unsorted singly linked list. Suppose it has its representation with a head pointer only.
Given the representation, which of the following operations can be implemented in O(1) time?         
i) Insertion at the front of the linked list

ii) Insertion at the end of the linked list

iii) Deletion of the front node of the linked list

iv) Deletion of the last node of the linked list

• I and II

• I and III

• I, II and III

•  I, II, and IV

Question 15

Which of the following statements is true?

• Recursion is always better than iteration

• Recursion uses more memory compared to iteration

• Recursion uses less memory compared to iteration

• Iteration is always better and simpler than recursion

Question 16

The no. of external nodes in a full binary tree with n internal nodes is?   

• n

• n+1

• 2n

• 2n + 1

Question 17

What is true about a break statement ?

• Break stops the execution of the entire program

• Break halts the execution and forces the control out of the loop

• Break forces the control out of the loop and starts the execution of next iteration

• Break halts the execution of the loop for certain time frame

Question 18

The balance factor of a node in a binary tree is defined as _____

• addition of heights of left and right subtrees

• height of right subtree minus height of left subtree

• height of left subtree minus height of right subtree

• height of right subtree minus one

Question 19

Which of the following sorting algorithm takes the least time when applied to an almost sorted array?

• Quick sort

• Insertion sort

• Selection sort

• Merge sort

Question 20

In a nested loop,the outer loop must be terminated before the inner loop.

• True

• False