(Backup) DSA and Code Snippets

Which operation does the above code perform?

• Enqueue

• Dequeue

• Return the front element

• Both b and c

Answer explanation

Two operations are performed in the above code. The first one is returning the value of the front with the help of the statement n=q[front], and the second operation is dequeue (deleting an element) by using the statement front++.

The minimum number of stacks needed to implement a queue is

• 3

• 1

• 2

• 4

Answer explanation

Two stacks S1 & S2 are required to implement a queue.This method makes sure that newly entered element is always at the top of stack 1, so that DeQueue operation just pops from stack1. To put the element at top of stack1, stack2 is used.

Which one of the following is the process of inserting an element in the stack?

• Insert

• Add

• Push

• None of the above

Answer explanation

In stack, the process of inserting an element is known as a push operation.

The process of deleting an element is known as a pop operation

The following numbers are inserted into an empty binary search tree in the given order: 10, 1, 3, 5, 15, 12, 16. What is the height of the binary search tree (the height is the maximum distance of a leaf node from the root)?

• 2

• 3

• 4

• 6

Answer explanation

So, height of the tree is 3, option (B) is correct.

Which data structure is required to convert the infix to prefix notation?

• Stack

• Linked List

• Binary Tree

• Queue

Answer explanation

Stack is a data structure used to reverse the order of the operators in the expression. It is also used as a storage structure that stores all the operators and print all the operators when all the operands have appeared

Find the output of the given code.

• 4 7.97

• 4 7.96623

• Compilation Error

• None of the above

Answer explanation

In the above program the float variable ft is intialised to 7.96623

It rounded of to 7.97 because of %.2f in printf statement.

Find the output.

(Note: Consider it in 16 bit machine)

• 12 10

• 14 10

• 6 2

• error

Answer explanation

In here the variable empid occupies 10 bytes because its an integer array with limit of 5 (5*2)

And the pointer variable occupies 2 bytes.

Therefore size of employee be

(5*2)+2+2=14 Bytes

What will be the output for the following?

• 15

• 3

• Syntax error

• 2

Answer explanation

Here, the array elements are accessed using the pointer notation.

from the example,

*a return the a[0]

*( a + i ) return a[i]

we are adding all the even indices elements, and subtracting all the elements at odd indices, which gives a result of 3.

What will be the output?

• Error

• 24

• 34

• Garbage Value

Answer explanation

We had defined the Variable Val as 4*(6+2) which is equal to 24

when we add 10 to Val it becomes 34.

So the output is 34.

Find the output of the snippet.

• 5

• 1

• Compilation Error

• Run time Error

Answer explanation

The difference between two pointer will always be 1.