What is a singly linked list, and how does it work?

A singly linked list is a linear data structure where each element points to the next element in the sequence.

A singly linked list is composed of nodes and references/links pointing to the next node in the sequence. Each node in a list consists of two parts: data and a reference (in other words, a link) to the next node in the sequence. This structure allows for efficient insertion and removal of elements from any position in the sequence during iteration.

The entry point into a linked list is called the head of the list. It should be noted that the first node does not have a previous node, while the last node does not have a next node. The last node of a list is identified because its next portion points to NULL.

To traverse a singly linked list, you start from the head node and follow the references to the next node until you reach the end (NULL). If you want to add an element to the list, a new node is created and its reference is set to the next node. The previous node's reference is then set to the new node. To remove an element, you adjust the reference of the previous node to point to the next node, bypassing the current node.

One of the key advantages of a singly linked list is that it allows dynamic memory allocation. Unlike arrays, where the size is fixed at compile time, linked lists can grow and shrink in size as needed at runtime. However, they do have some drawbacks. For instance, they have a higher overhead compared to arrays due to storage of additional next references. Also, direct access to individual elements is not possible; to access an element, you must start from the head and follow the references.

In summary, a singly linked list is a simple yet powerful data structure that is particularly useful when you need to frequently add and remove elements, and when you don't know the maximum number of elements in advance.