delete a head node in link list

To delete a head node in a linked list in C++, follow these steps:

1. Create a temporary pointer called temp and point it to the head of the linked list.
2. Move the head pointer to the next node in the linked list.
3. Delete the node that temp is pointing to.
4. Set the temp pointer to nullptr to avoid any dangling pointers.
5. Free the memory occupied by the node pointed to by temp.

Here is the code snippet that demonstrates these steps:

void deleteHeadNode(Node*& head) {
    if (head == nullptr) {
        // Linked list is empty, nothing to delete
        return;
    }

    Node* temp = head;
    head = head->next;
    delete temp;
    temp = nullptr;
}

In this code, Node is the struct or class representing each node in the linked list, and next is a pointer to the next node. The head parameter is passed by reference to update the head pointer in the calling function.

The first step checks if the linked list is empty. If it is, there is nothing to delete, so the function returns.

Next, the temp pointer is set to the current head node.

Then, the head pointer is moved to the next node by assigning head to head->next.

After that, the node pointed to by temp is deleted using the delete keyword.

To avoid any potential issues with dangling pointers, the temp pointer is set to nullptr.

Finally, the memory occupied by the node pointed to by temp is freed using the delete operator.

By following these steps, you can successfully delete the head node in a linked list using C++.