node structure

#include <stdio.h>
#include <stdlib.h>

// Define the node structure
struct node {
    int data;
    struct node *next;
};

struct node *head = NULL;

// Function to insert a node at the beginning
void insert_at_beginning(int data) {
    struct node *newnode, *temp;
    
    // Corrected malloc syntax: sizeof(struct node)
    newnode = (struct node*)malloc(sizeof(struct node));
    newnode->data = data;

    if (head == NULL) {
        // If list is empty, node points to itself
        newnode->next = newnode;
        head = newnode;
    } else {
        temp = head;
        // Traverse to the last node
        while (temp->next != head) {
            temp = temp->next;
        }
        
        // Link new node to current head
        newnode->next = head;
        // Last node now points to the new first node
        temp->next = newnode;
        // Update head to the new node
        head = newnode;
    }
    printf("Inserted %d at the beginning.\n", data);
}

// Function to display the list
void display() {
    struct node *temp;
    if (head == NULL) {
        printf("List is empty.\n");
        return;
    }
    temp = head;
    printf("Circular List: ");
    do {
        printf("%d -> ", temp->data);
        temp = temp->next;
    } while (temp != head);
    printf("(head)\n");
}

int main() {
    insert_at_beginning(30);
    insert_at_beginning(20);
    insert_at_beginning(10);

    display();

    return 0;
}