Cylcic Linked List

#include <iostream>

using namespace std;

struct Node {
    int data;
    struct Node* next;
}*head = NULL;

void add(int arr[], int n, struct Node** head)
{
    struct Node* first;
    first = new Node;
    first->data = arr[0];
    first->next = NULL;
    struct Node* prev = first;
    for (int i = 1; i < n; i++) {
        struct Node* t = new Node;
        t->data = arr[i];
        t->next = NULL;
        prev->next = t;
        prev = t;
    }

    (*head) = first;
    prev->next = first;
}

void display(struct Node* p)
{
    struct Node* t = p;
    do {
        cout << p->data << endl;
        p = p->next;
    } while (p != t);
}

int main()
{
    int arr[] = { 10, 20, 30 };
    add(arr, sizeof(arr) / sizeof(arr[0]), &head);
    display(head);
}