Basics of C and DS

Which of the following is a correct syntax to declare a variable in C?

• A) int num;

• B) int = num;

• C) num int;

• D) variable int;

2.What does the sizeof operator do in C?

• A) Returns the size of a variable in bytes

• B) Returns the size of a variable in bits

• C) Allocates memory dynamically

• D) None of the above

3.Which function is used to get input from the user in C?

• A) scanf()

• B) printf()

• C) input()

• D) gets()

4.What is the correct way to declare a pointer to an integer in C?

• A) int *ptr;

• B) pointer int ptr;

• "C) int ptr*;

• D) int ptr;

5.Which operator is used to access a member of a structure through a pointer?

• • A) . (dot operator)

• B) -> (arrow operator)

• C) & (address-of operator)

• D) * (dereference operator)

6.What is the time complexity of accessing an element in an array?

• A) O(1)

• B) O(n)

• C) O(log n)

• D) O(n^2)

7.In a singly linked list, which operation is performed in O(1) time complexity?

• A) Inserting at the end

• B) Deleting from the beginning

• C) Accessing an element by index

• D) Inserting at a specific position

8.Which data structure uses LIFO (Last In, First Out) order?

• A) Queue

• B) Array

• C) Stack

• D)Linked list

9.What is the maximum number of children each node can have in a binary tree?

• A) 1

• B) 2

• C

• D

10.In a binary search tree (BST), which property is maintained?

• A) All nodes have at most two children

• B) The tree is always balanced

• C) The left and right subtrees are of equal height

• D) The left child’s value is less than the parent’s value, and the right child’s value is greater