A linked list is a linear data structure where elements, called nodes, are connected through pointers. Each node contains two parts: the data and a reference (or pointer) to the next node in the sequence. Here’s a breakdown of the key concepts:
Components of a Linked List
- Node: The basic unit of a linked list, which contains:
- Data: The value or information the node holds.
- Next: A pointer/reference to the next node in the list.
- Head: The first node in the linked list. It is used to access the entire list.
- Tail: The last node in the linked list, which points to null (or None in Python) indicating the end of the list.
Types of Linked Lists
- Singly Linked List: Each node points to the next node; traversal is one-way.
- Doubly Linked List: Each node points to both the next and the previous node; allows traversal in both directions.
- Circular Linked List: The last node points back to the first node, forming a circle.
Basic Operations
- Insertion: Adding a new node to the list (at the beginning, end, or a specific position).
- Deletion: Removing a node from the list (by value or position).
- Traversal: Visiting each node in the list to access or display the data.
- Search: Finding a node with a specific value.
Advantages
- Dynamic size: Can grow or shrink as needed.
- Efficient insertions/deletions: Especially at the beginning or end.
Disadvantages
- No direct access: Unlike arrays, nodes cannot be accessed directly by index.
- Extra memory: Requires more memory for storing pointers.