Data Structure

1. Which of the following properties is associated with a queue?

• a) First In Last Out

• b) First In First Out

• c) Last In First Out

• d) Last In Last Out

Consider an implementation of unsorted singly linked list. Suppose it has its representation with a head pointer only. Given the representation, which of the following operation 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

• a) I and II

• b) I and III

• c) I, II and III

• d) I, II and IV

Answer explanation

Answer: bExplanation: We know the head node in the given linked list. Insertion and deletion of elements at the front of the linked list completes in O (1) time whereas for insertion and deletion at the last node requires to traverse through every node in the linked list. Suppose there are n elements in a linked list, we need to traverse through each node. Hence time complexity becomes O(n).

In linked list implementation of a queue, front and rear pointers are tracked. Which of these pointers will change during an insertion into a NONEMPTY queue?

• a) Only front pointer

• b) Only rear pointer

• c) Both front and rear pointer

• d) No pointer will be changed

Answer explanation

Answer: bExplanation: Since queue follows FIFO so new element inserted at last.

The associativity of an exponentiation operator ^ is right side.

• a) True

• b) False

What would be the Prefix notation for the given equation?

A+(B*C)

• a) +A*CB

• b) *B+AC

• c) +A*BC

• d) *A+CB

Answer explanation

Answer: cExplanation: Reverse the equation or scan the equation from right to left. Apply the infix-postfix algorithm. The equation inside the bracket evaluates to CB* and outside the bracket evaluates to A+ therefore getting CB*A+. Reversing this and we get +A*BC.

1. Which of the following is false about a binary search tree?

• a) The left child is always lesser than its parent

• b) The right child is always greater than its parent

• c) The left and right sub-trees should also be binary search trees

• d) In order sequence gives decreasing order of elements

What is the speciality about the inorder traversal of a binary search tree?

• a) It traverses in a non increasing order

• b) It traverses in an increasing order

• c) It traverses in a random fashion

• d) It traverses based on priority of the node

for an int of size 4 bites what is the size of arr[15]

• a. 19

• 15

• 60

• 11

What does the following piece of code do?

public void func(Tree root)

{

func(root.left());

func(root.right());

System.out.println(root.data());

}

• a) Preorder traversal

• b) Inorder traversal

• c) Postorder traversal

• d) Level order traversal

How will you find the minimum element in a binary search tree?

• while(root.left() != null)

  {

  root = root.left();

  } System.out.println(root.data());

• while(root != null)

  { root = root.left(); } System.out.println

  (root.data());

• while(root.right() != null) { root = root.right(); } System.out.println(root.data());

• while(root != null) { root = root.right(); } System.out.println(root.data());