Linked List

A linked list is a linear data structure used in computer science to organize and store a collection of elements called nodes. Unlike arrays, which store elements in contiguous memory locations, linked lists use nodes that contain data and a reference (or link) to the next node in the sequence. This arrangement allows for dynamic memory allocation and efficient insertion and deletion of elements.

Here’s a brief explanation of how a linked list works:

1. Nodes: Each node in a linked list contains two main components: data and a reference to the next node (or null if it’s the last node in the list).
2. Head: The linked list starts with a special node called the “head.” The head serves as the starting point for traversing the list.
3. Traversal: To access the elements in a linked list, you start from the head and follow the references to subsequent nodes. This process is called traversal.
4. Insertion: Inserting a new element involves creating a new node, updating the references of neighboring nodes to include the new node, and adjusting the references accordingly.
5. Deletion: Deleting a node involves updating the references of neighboring nodes to bypass the node being removed, and then releasing the memory occupied by the removed node.
6. Types of Linked Lists: There are different types of linked lists, including singly linked lists (each node has a reference to the next node), doubly linked lists (each node has references to both the next and previous nodes), and circular linked lists (the last node’s reference points back to the head).

Linked lists offer advantages such as dynamic memory allocation, efficient insertion and deletion operations, and the ability to handle varying sizes of data. However, they can be less memory-efficient due to the overhead of storing references for each node.

• What is Linked List?
  A linked list is a fundamental data structure in computer science used for storing and organizing a collection of elements called nodes. Unlike arrays, which use contiguous memory, linked lists utilize non-contiguous memory and each node contains two parts: the data and a reference (pointer) to the next node in the sequence.
• Reverse Linked List
  Given the head of a singly linked list, reverse the list in-place and return the new head of the reversed linked list.
• Rotate List
  Given the head of a singly linked list and an integer k, rotate the linked list to the right by k places. The rotation means moving the last k nodes to the front of the list.
• Reverse Linked List II
  Given the head of a singly linked list and two integers left and right, reverse…
• Reverse Nodes in k-Group
  Given the head of a singly linked list and an integer k, reverse the nodes…
• Linked List Cycle
  Given a linked list, determine if it has a cycle in it. A cycle is when a node in the linked list points to a previously visited node, forming a loop. Return true if there is a cycle, otherwise, return false.
• Linked List Cycle II
  Given a linked list, determine if it contains a cycle. If a cycle is present, find the node where the cycle begins and return it. If there is no cycle, return nullptr.
• Middle of the Linked List
  Given a singly-linked list, find the middle node of the list. If the list contains an even number of nodes, return the second middle node.
• Merge K Sorted Lists
  You are given an array of k linked lists, each linked list is sorted in ascending order. Merge all the linked lists into one sorted linked list and return it.