// Pantea Aria


// 1) How could I print the data in the first node?
// 2) How could I print the data in the second node?
// 3) How could I modify the next field in the first node to be NULL? What would that do?

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

struct node {
    int data;
    struct node *next;
};

struct node *create_node(int data, struct node *next);

int main(void) {

    // Build a simple list with 3 nodes: 10 -> 20 -> 30 -> NULL
    struct node *third  = create_node(30, NULL);
    struct node *second = create_node(20, third);
    struct node *head   = create_node(10, second);

    printf("List is: 10 -> 20 -> 30 -> NULL\n");

    // TODO 1: Print the data in the first node (head).
    // Hint: the first node is head itself.
    printf("First node data: %d\n", head->data);

    // TODO 2: Print the data in the second node.
    // Hint: the second node is the node after head.
    printf("Second node data: %d\n", head->next->data);

    // TODO 3: Set the next field in the first node to NULL.
    // What would that do?
    // Hint: it "cuts" the list after the first node.
    //
    head->next = NULL;

    // After TODO 3, try printing what the head points to now:
    printf("\nAfter setting head->next to NULL:\n");
    printf("Head data: %d\n", head->data);

    // TODO 4 (optional): Check if there is still a second node reachable from head.
    // If you cut the list correctly, head->next should be NULL.
     if (head->next != NULL) {
         printf("There is still a second node reachable!\n");
     } else {
         printf("No second node reachable from head (list was cut).\n");
     }

    // Cleanup:
    // IMPORTANT: If you cut the list, you *still* need to free the other nodes
    // using the pointers you saved (second, third), otherwise you leak memory.
    free(head);
    free(second);
    free(third);

    return 0;
}


struct node *create_node(int data, struct node *next) {
    struct node *new_node = malloc(sizeof(struct node));
    if (new_node == NULL) {
        printf("Out of memory\n");
        exit(1);
    }
    new_node->data = data;
    new_node->next = next;
    return new_node;
}