If the previous pointer of the last node is NULL

If the next pointer of the last node is NULL

If the tail is NULL

If the head is NULL

The head remains NULL

Only the next pointer is set

Both prev and next pointers are set to NULL

The tail pointer is left unchanged

3

0

1

2

Implementing queues

Implementing stacks

Binary search tree

Undo/Redo functionality in text editors

Each node contains two pointers, one pointing to the next node and one to the previous node

Insertion is only possible at the head

It cannot have more than two nodes

Deletion is only possible at the tail

4

3

1

2

Cannot be implemented in programming

More complex insertion and deletion

Requires less memory

Can be traversed in both forward and backward directions

Using a stack

Using a separate pointer

Storing node addresses in an array

Using recursion

Compare node values one by one while traversing

Sort both lists and compare

Check if their head pointers are equal

Check if their tail pointers are equal