// c++ program to create a linked list insert element at head, at tail and delete element from
// tail, head and specific key
#include <iostream>
using namespace std;
struct Node
{
public:
    int data;
    Node *next;
    Node(int data)
    {
        this->data = data;
        this->next = NULL;
    }
};
void insertAtHead(Node *&head, int data)
{
    Node *NewNode = new Node(data);
    NewNode->next = head;
    head = NewNode;
}
void insertAtTail(Node *&head, int data)
{
    Node *NewNode = new Node(data);
    if (head == NULL)
    {
        NewNode->next = head;
        head = NewNode;
        return;
    }
    Node *temp = head;
    while (temp->next != NULL)
    {
        temp = temp->next;
    }
    temp->next = NewNode;

    cout << "the value of temp next is " << temp->data << endl;
}
void insertAtKey(Node *&head, int key, int data)
{
    Node *NewNode = new Node(data);
    if (head->data == key)
    {

        NewNode->next = head->next;
        head->next = NewNode;
        return;
    }
    Node *temp = head;
    while (temp->data != key)
    {
        temp = temp->next;
        if (temp == NULL)
            return;
    }
    NewNode->next = temp->next;
    temp->next = NewNode;
}
void print(Node *&head)
{
    if (head == NULL)
    {
        cout << head->data << " ->  ";
    }
    Node *temp = head;
    while (temp != NULL)
    {
        /* code */
        cout << temp->data << " -> ";
        temp = temp->next;
    }
}

void deleteNode(Node *&head, int key)
{
    if (head == NULL)
        return;

    if (head->data == key)
    {
        Node *temp = head;
        head = head->next;
        delete temp;
    }
    deleteNode(head->next, key);
}
int main()
{
    Node *head = NULL;
    cout << "insert At head" << endl;
    insertAtHead(head, 3);
    insertAtHead(head, 2);
    print(head);
    cout << endl;
    cout << "Insert at Tail " << endl;
    insertAtTail(head, 4);
    insertAtTail(head, 5);
    insertAtTail(head, 6);
    insertAtTail(head, 10);
    insertAtTail(head, 9);
    insertAtKey(head, 10, 45);
    print(head);

    deleteNode(head, 2);
    cout << "deleting the head" << endl;
    print(head);
}