Introduction to Data Structures MCQs with Answers 2027

Q121

Which of the following array position will be occupied by a new element being pushed for a stack of size N elements(capacity of stack > N)?

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Q122

Open question

Consider you have a stack whose elements in it are as follows.
5 4 3 2 << top
Where the top element is 2.
You need to get the following stack
6 5 4 3 2 << top
The operations that needed to be performed are (You can perform only push and pop):

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Q123

Open question

Which data structure is used for implementing recursion?

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Q124

Open question

Which of the following data structures can be used for parentheses matching?

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Q125

Open question

Here is an infix expression: 4 + 3*(6*3-12). Suppose that we are using the usual stack algorithm to convert the expression from infix to postfix notation. The maximum number of symbols that will appear on the stack AT ONE TIME during the conversion of this expression?

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Q126

Open question

A Double-ended queue supports operations such as adding and removing items from both the sides of the queue. They support four operations like addFront(adding item to top of the queue), addRear(adding item to the bottom of the queue), removeFront(removing item from the top of the queue) and removeRear(removing item from the bottom of the queue). You are given only stacks to implement this data structure. You can implement only push and pop operations. What are the total number of stacks required for this operation?(you can reuse the stack)

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Q127

Open question

What is the functionality of the following piece of code?

public void display() 
{
	if(size == 0)
		System.out.println("underflow");
	else
	{
		Node current = first;
		while(current != null)
		{
			System.out.println(current.getEle());
			current = current.getNext();
		}
	}
}

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Q128

Open question

What is the output of the following Java code?

public class array
{
	public static void main(String args[])
	{
		int []arr = {1,2,3,4,5};
		System.out.println(arr[5]);
	}
}

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Q129

Open question

You are given pointers to first and last nodes of a singly linked list, which of the following operations are dependent on the length of the linked list?

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Q130

Open question

Which of the following points is/are not true about Linked List data structure when it is compared with an array?

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Q131

Open question

Which of the following application makes use of a circular linked list?

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Q132

Open question

To implement a stack using queue(with only enqueue and dequeue operations), how many queues will you need?

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Q133

Open question

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

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Q134

Open question

What is the functionality of the following code? Choose the most appropriate answer.

public int function()
{
	if(head == null)
		return Integer.MIN_VALUE;
	int var;
	Node temp = head;
	Node cur;
	while(temp.getNext() != head)
	{
		cur = temp;
		temp = temp.getNext();
	}
	if(temp == head)
	{
		var = head.getItem();
		head = null;
		return var;
	}
	var = temp.getItem();
	cur.setNext(head);
	return var;
}

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Q135

Open question

What does the following function do for a given Linked List with first node as head?

void fun1(struct node* head)
{
    if(head == NULL)
    return;
    fun1(head->next);
    printf("%d  ", head->data);
}

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Q136

Open question

A normal queue, if implemented using an array of size MAX_SIZE, gets full when?

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Q137

Open question

Process of inserting an element in stack is called . . . . . . . .

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Q138

Open question

Convert the following Infix expression to Postfix form using a stack.
x + y * z + (p * q + r) * s, Follow usual precedence rule and assume that the expression is legal.

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Q139

Open question

After performing these set of operations, what does the final list look contain?

InsertFront(10);
InsertFront(20);
InsertRear(30);
DeleteFront();
InsertRear(40);
InsertRear(10);
DeleteRear();
InsertRear(15);
display();

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Q140

Open question

Circular Queue is also known as . . . . . . . .

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Introduction to Data Structurespractice.

Introduction to Data Structures
practice.