Insertion at the Beginning in Doubly Linked List
Insertion at the Beginning in Doubly Linked List
To insert a new node at the beginning of the doubly list, we can use the following steps:
- Allocate memory for a new node and assign the provided value to its data field.
- Set the previous pointer of the new node to nullptr.
- If the list is empty:
- Set the next pointer of the new node to nullptr.
- Update the head pointer to point to the new node.
- If the list is not empty:
- Set the next pointer of the new node to the current head.
- Update the previous pointer of the current head to point to the new node.
- Update the head pointer to point to the new node.
Below are the implementation of the above approach:
// Define the structure for a node in the doubly linked list
struct Node {
int data; // Data stored in the node
Node* next; // Pointer to the next node
Node* prev; // Pointer to the previous node
};
// Function to insert a node at the beginning of the list
void insertBeginning(Node*& head, int value) {
// Create a new node
Node* newNode = new Node;
// Assign the value to the new node
newNode->data = value;
// Since it's the first node, the previous pointer is nullptr
newNode->prev = nullptr;
// If the list is empty, make the new node the head
if (head == nullptr) {
// Since it's the only node, the next pointer is nullptr
newNode->next = nullptr;
// Update the head pointer to point to the new node
head = newNode;
} else {
// Point the new node's next pointer to the current head
newNode->next = head;
// Update the previous pointer of the current head to point to the new node
head->prev = newNode;
// Update the head pointer to point to the new node
head = newNode;
}
}
Doubly Linked List Tutorial
A doubly linked list is a more complex data structure than a singly linked list, but it offers several advantages. The main advantage of a doubly linked list is that it allows for efficient traversal of the list in both directions. This is because each node in the list contains a pointer to the previous node and a pointer to the next node. This allows for quick and easy insertion and deletion of nodes from the list, as well as efficient traversal of the list in both directions.
Doubly Linked List in Data Structure