Linked List Insertion

Insertion of an element at the middle of a linked list requires the modification of how many pointers?

• 3

• 1

• 2

• 4

Answer explanation

2 pointers are needed to be modified for insertion in the middle of a linked list, the node before the node to be inserted and the node which is being inserted

What is the time complexity to insert an element to the front of a LinkedList

(head pointer given)?

• O(n)

• O(1)

• O(log n)

• None of the above

Answer explanation

We set the next node to the head of the list, and then return that node as the new head.It requires a time complexity of O(1)

What is the time complexity to insert an element to the rear of a LinkedList

(head pointer given)?

• O(n)

• O(1)

• O(log n)

• None of the above

Answer explanation

We need to traverse to the end of the LinkedList and set it next to the new element. So, the traversal will take O(n) time complexity

Which part of code represents the statement "Assign newly created node’s next ptr to current head reference. So, it points to the previous start node of the linked list address"

• newNode ->data=data

• newNode ->next= *head

• *head = newNode

• struct Node newNode = (struct Node ) malloc (sizeof (struct Node))

Answer explanation

newNode - >next== *head

Assigns newly created node’s next ptr to current head reference. So, it points to the previous start node of the linked list address

What is the space complexity needed to store a linked list of n nodes?

• O(1)

• O(n)

• O(n^2)

• None of the above

Answer explanation

For n nodes we need a space complexity of O(n)

Which of the following linked list operation takes O(1) time?

• Insert element at start of the list

• Insert element at end of the list

• Find length of the list

• None of the above

Answer explanation

Only inserting an element at start of linked list takes O(1) time.

Using the above code try inserting 25 after 3rd position for the following linkedlist,

20 16 12 10 14 18 11

Then where does 25 lie between

• between 16 and 12

• between 12 and 10

• between 10 and 14

• None of the above

Answer explanation

Inserting 25 leads to insertion between 12 and 10.Since element 12 is in the 3rd position

In the above code what does "temp" and "ptr" nodes represent respectively

• temp=node at position 'n' ptr=new node to be inserted

• ptr=node at position 'n' temp=new node to be inserted

• temp= last node ptr=new node

• ptr= last node temp=new node

Answer explanation

temp node can be used to traverse the linked list and find the node at specific position 'n' and ptr represents the new node to be inserted

In a linked list, insertion can be done as

• beginning

• end

• middle

• all of the above

Answer explanation

Linked List Insertion can be done using one of the following ways

Insertion at the beginning

Insertion after specific node

Insertion at the middle

Insertion at the end

What is the functionality of the above code?

• Inserting a node at the beginning of the list

• Deleting a node at the beginning of the list

• Inserting a node at the end of the list

• Deleting a node at the end of the list

Answer explanation

The for loop traverses through the list and then inserts a new node as cur.setNext(node)