Question: What will be the output of the following code snippet?

int arr[5] = {1, 2, 3, 4, 5};

printf("%d", arr[5]);

• 5

• 0

• Garbage Value

• Compilation Error

What is the time complexity of accessing an element in an array by its index?

• O(1)

• O(n)

• O(log n)

• O(n^2)

What is the time complexity of the following code?

for(int i = 0; i < n; i++) {

for(int j = 0; j < n; j++) {

printf("Hello");

} }

• O(n)

• O(n log n)

• O(n^2)

• O(log n)

What does the following code do?

struct Node {

int data;

struct Node* next; };

struct Node* head = NULL;

head->data = 10;

• Creates a node with data 10

• Causes a segmentation fault

• Initializes an empty linked list

• Links two nodes

Answer explanation

• head is NULL, so dereferencing it (head->data) causes a segmentation fault.

What is the time complexity of inserting a node at the end of a singly linked list with no tail pointer?

• O(1)

• O(n)

• O(n log n)

• O(n^2)

Spot the error:

struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));

newNode->data = 5;

newNode->next = newNode;

• No error

• Creates a circular reference

• Missing free() call

• Incorrect malloc syntax

Answer explanation

8. Setting newNode->next = newNode creates a circular linked list, which may not be intended.

How many moves are required to solve the Tower of Hanoi puzzle with 5 disks?

• 32

• 16

• 31

• 25

Find the error in this stack push operation:

void push(int stack[], int* top, int value) {

stack[++(*top)] = value;

}

• No error

• Missing bounds check

• Incorrect increment syntax

• Value not assigned correctly

Answer explanation

The code doesn’t check if the stack is full before incrementing top, risking overflow.

What will this code output?

int arr[3] = {1, 2, 3};

for(int i = 0; i <= 3; i++) {

printf("%d ", arr[i]);

}

• 1 2 3

• 1 2 3 0

• 1 2 3 followed by garbage

• Compilation error

Which line contains an error?

1: struct Node* head = NULL;

2: head = (struct Node*)malloc(sizeof(struct Node));

3: head->data = 10;

4: free(head->next);

• Line 1

• Line 2

• Line 3

• line 4