linked list complete notes

                    LINKED LIST (complete notes)

• A linked list is a linear data structure in which each element (called a "node") is stored in a separate block of memory, and the elements are linked together using pointers. A linked list consists of a head and a tail, with the head pointing to the first node in the list and the tail pointing to the last node.
• There are two main types of linked lists: singly linked lists and doubly linked lists. In a singly linked list, each node contains a pointer to the next node in the list, while in a doubly linked list, each node contains pointers to both the next and previous nodes in the list.

Some benefits of using a linked list include:

• They can be easily inserted or deleted from the list, as you only need to update the pointers of the surrounding nodes.
• They do not require contiguous blocks of memory, which makes them a good choice for managing large lists or lists that will grow or shrink frequently.
• They can be implemented using a dynamic array, which allows for efficient resizing of the list.

Some drawbacks of using a linked list include:

• They require more memory than an array, as each element requires an additional pointer to be stored.
• They do not provide constant-time access to individual elements, as you have to follow the pointers from the head of the list to get to a specific element.

Here are some common operations that can be performed on a linked list:

• Inserting a new node at the beginning, end, or middle of the list
• Deleting a node from the list
• Searching for a specific node in the list
• Traversing the list (i.e., visiting each node in the list in order)
• Reversing the list
• Sorting the list

• In a singly linked list, the head node typically has a null value for its "next" pointer, while the tail node has a null value for its "next" pointer and all nodes in between have a non-null value.
• In a doubly linked list, both the head and tail nodes typically have null values for their "next" and "previous" pointers, while all other nodes have non-null values for both pointers.
• When inserting a new node into a linked list, you'll need to update the pointers of the surrounding nodes to point to the new node. For example, if you're inserting a new node at the beginning of a singly linked list, you'll need to update the "next" pointer of the new node to point to the head node, and then update the head node to point to the new node.
• When deleting a node from a linked list, you'll need to update the pointers of the surrounding nodes to point around the deleted node. For example, if you're deleting the second node in a singly linked list, you'll need to update the "next" pointer of the first node to point to the third node, and update the "next" pointer of the third node to point to the fourth node (if it exists).

• Linked lists can be implemented using a single-linked list, in which each node has a single "next" pointer, or a double-linked list, in which each node has both a "next" and "previous" pointer.
• Linked lists are often used to implement stack and queue data structures, as well as graph algorithms and other types of dynamic data structures.
• Linked lists have a time complexity of O(n) for most operations, as you typically have to traverse the list to perform an operation on a specific element. However, some operations, such as inserting or deleting a node from the beginning or end of the list, can be performed in O(1) time.
• One common use of linked lists is to implement a stack, which is a Last In First Out (LIFO) data structure. In a stack implemented using a linked list, you can push an element onto the stack by inserting it at the beginning of the list, and pop an element off the stack by deleting it from the beginning of the list.
• Another common use of linked lists is to implement a queue, which is a First In First Out (FIFO) data structure. In a queue implemented using a linked list, you can enqueue an element by inserting it at the end of the list, and dequeue an element by deleting it from the beginning of the list.
• Linked lists can also be used to implement dynamic data structures, such as trees and graphs, where the structure of the data changes over time.
• Linked lists can be traversed in either a forward or backward direction, depending on whether you follow the "next" or "previous" pointers.
• Linked lists can be implemented using a variety of programming languages, including C, C++, Java, and Python.
• To avoid memory leaks, it's important to properly deallocate memory when deleting nodes from a linked list. This can be done using the free() function in C or C++, or by using the delete operator in Java.
• One important property of linked lists is that they do not have a fixed size, unlike arrays, which have a fixed size that must be determined at the time of allocation. This means that you can add or remove elements from a linked list without having to worry about running out of space or having to allocate a new block of memory.
• One disadvantage of linked lists is that they do not provide constant-time access to individual elements, as you have to follow the pointers from the head of the list to get to a specific element. This can make certain operations, such as searching for a specific element or accessing the nth element, slower than they would be in an array.
• Linked lists can be used to implement a variety of data structures, including stacks, queues, and dynamic data structures such as trees and graphs.
• In a singly linked list, you can only traverse the list in one direction, from the head to the tail. In a doubly linked list, you can traverse the list in either direction.

• When implementing a linked list, you'll need to decide whether to use a singly linked list or a doubly linked list. A singly linked list requires less memory, as each node only needs to store a single pointer, but a doubly linked list is more flexible, as you can easily traverse the list in either direction.
• It's important to consider the trade-offs between using a linked list and other data structures, such as arrays or dynamic arrays, depending on the specific requirements of your application.
• One important property of linked lists is that they can be easily resized, as you can insert or delete elements from the list without having to allocate a new block of memory or copy the elements to a new location.
• Linked lists can be used to implement a variety of data structures, including stacks, queues, and dynamic data structures such as trees and graphs.
• In a singly linked list, you can only traverse the list in one direction, from the head to the tail. In a doubly linked list, you can traverse the list in either direction.
• When implementing a linked list, you'll need to decide whether to use a singly linked list or a doubly linked list. A singly linked list requires less memory, as each node only needs to store a single pointer, but a doubly linked list is more flexible, as you can easily traverse the list in either direction.
• It's important to consider the trade-offs between using a linked list and other data structures, such as arrays or dynamic arrays, depending on the specific requirements of your application.
• To avoid memory leaks, it's important to properly deallocate memory when deleting nodes from a linked list. This can be done using the free() function in C or C++, or by using the delete operator in Java.
• When inserting or deleting elements from a linked list, you'll need to update the pointers of the surrounding nodes to point to the new or deleted elements.