A linked list is a common data structure that stores a sequence of values, called nodes. Each node contains a value and a reference to the next node in the list. The reference may be a pointer or a memory address. This way, the nodes are not stored in contiguous memory locations like arrays, but rather linked together using pointers or references.
For example, let’s consider a singly linked list of integers 1, 2, 3, 4. It would consist of four nodes:
In this example, each node stores an integer value, and the reference or pointer “next” points to the next node in the list. The last node has a NULL reference for “next,” indicating the end of the list.
Linked lists can be used to implement various data structures like stacks, queues, and hash tables. They are efficient for inserting and deleting elements from the list, but accessing individual nodes can be slower than in arrays because it requires sequential traversal.
A linked list is a collection of nodes, each with a piece of data and a reference to the next node in the sequence.
The first node in a linked list is called the head, and the last node is called the tail.
Linked lists can be singly-linked, where each node only references the next node in the sequence, or doubly-linked, where each node also references the previous node.
Linked lists can be used to implement dynamic data structures, such as stacks, queues, and hash tables.
Inserting or deleting a node in a linked list is efficient, as it only requires modifying the references of adjacent nodes.
Accessing a particular node in a linked list is less efficient than in an array or ArrayList, as it requires traversing the list from the head or tail to find the desired node.
Linked lists are not suitable for applications that require random access to elements, as they do not support direct indexing.
Linked lists can be used to implement sorting algorithms, such as merge sort and insertion sort, which depend on efficient merging and splitting of sequences.
What is a linked list and how is it different from other data structures?
Answer: A linked list is a linear data structure that consists of a head node and a set of nodes that each has a reference to the next node in the list. It differs from arrays and other data structures in that it allows for dynamic memory allocation and is well-suited for inserting and deleting elements in the middle of the list.
What is the time complexity of searching for an element in a singly linked list?
Answer: The time complexity of searching for an element in a singly linked list is O(n), where n is the number of elements in the list. This is because we must traverse the list from the head node until we find the element we are searching for or reach the end of the list.
How do you insert an element at the beginning of a linked list?
Answer: To insert an element at the beginning of a linked list, we create a new node with the value we want to insert and set its next node to the current head node. Then, we set the head of the list to the new node.
What is the difference between a singly linked list and a doubly linked list?
Answer: The difference between a singly linked list and a doubly linked list is that in a singly linked list each node only has a reference to the next node in the list, while in a doubly linked list each node has a reference to both the next and previous nodes in the list. This allows for more efficient traversal and operations such as inserting or deleting elements in the middle of the list.
How do you delete an element from a linked list?
Answer: To delete an element from a linked list, we first traverse the list to find the node that contains the value we want to delete. Once we find the node, we set the next reference of the previous node to the next node after the one we want to delete, effectively skipping over it. Then, we deallocate the memory used by the deleted node.