What is the difference between singly and multiply linked lists?

A singly linked list allows traversal in one direction only, while a multiply linked list allows traversal in multiple directions.

A singly linked list is a type of data structure where each node contains a data element and a reference (link) to the next node in the sequence. This allows for a linear traversal, meaning you can only move in one direction - from the first node (head) to the last node (tail). This type of list is simple and uses less memory as it only needs to store a single link to another node. However, it can be less efficient for certain operations, such as deletion or insertion of nodes at specific positions, as you may need to traverse from the head node to reach the desired position.

On the other hand, a multiply linked list, also known as a doubly linked list, is a more complex type of data structure. Each node in a doubly linked list contains a data element and two references, one to the next node and one to the previous node. This allows for bidirectional traversal, meaning you can move in both directions - from the head to the tail and vice versa. This makes certain operations, such as deletion or insertion at specific positions, more efficient as you can traverse from either end to reach the desired position. However, this type of list uses more memory as it needs to store two links per node.

There are also other types of multiply linked lists, such as circular linked lists, where the last node points back to the first node, creating a loop, or doubly circular linked lists, where you can move in both directions and the list loops back on itself. These types of lists can be useful for certain applications, but they are more complex and use even more memory.

In conclusion, the choice between a singly linked list and a multiply linked list depends on the specific requirements of your application, including memory usage, efficiency of operations, and complexity of implementation.