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I got this code from chat GPT.Can anyone explain me..How head and tail is connected in above code,because i am unable to understand that how address of tail is passed to head.

here is my code:

#include <iostream>
using namespace std;

class Node
{
public:
    int data;
    Node *next;
};

int main()
{
    Node *head = NULL; // Initialize the head pointer to null
    Node *tail = NULL; // Initialize the tail pointer to null

    // Create a loop to add new nodes to the linked list
    for (int i = 1; i <= 5; i++)
    {
        Node *newNode = new Node(); // Create a new node object
        newNode->data = i;          // Set the data variable for the new node
        newNode->next = NULL;       // Set the next pointer to null

        // If the list is empty, set the head and tail pointers to the new node
        if (head == NULL)
        {
            head = newNode;
            tail = newNode;
        }
        // Otherwise, add the new node to the end of the list and update the tail pointer
        else
        {
            tail->next = newNode;
            tail = newNode;
        }
    }

    // Print out the linked list
    Node *current = head;
    while (current != NULL)
    {
        cout << current->data << " ";
        current = current->next;
    }

    return 0;
}
ks1322
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Samee Ullah Jafar
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  • Run it step by step. In the first node-addition, when the list is empty, both "head" and "tail" are updated. In the rest of cases only previous "tail->next" must be updated and then the "tail" itself must point to the freshly created newNode. – Ripi2 May 13 '23 at 17:51
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    If ChatGPT wrote it, perhaps ChatGPT can explain it. – Paul Sanders May 13 '23 at 23:02
  • Don't use ChatGPT. Don't use [`using namespace std;`](https://stackoverflow.com/questions/1452721/why-is-using-namespace-std-considered-bad-practice). Don't use `NULL`, use [`nullptr`](https://stackoverflow.com/questions/1282295/what-exactly-is-nullptr) in C++ code. – David Conrad May 16 '23 at 18:22

1 Answers1

1

head and tail are connected through the inner elements.

At the start, they are both NULL, although it is better to use nullptr.

When the first node is added, both point to it. After that. tail will always point to the last element and head to the first.

action state after
start head = tail = NULL
first insert head = tail = new node -> NULL
second insert head = first node -> tail = second node -> NULL
third insert head = first node -> second node -> tail = third node -> NULL

Here, the convencion -> means to where the next field of the node point to. The equals sign, is to say what is the value of head and tail in each state.

Andrés Alcarraz
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