Linked List

#include<iostream>
using namespace std;
struct node
{
    int data;
    node *next;
};

class Linked_List
{
private:
    node *head, *tail;
public:
    Linked_List()
    {
        head=NULL;
        tail=NULL;
    }
    ///Function to add data in the last of the list
    void add_last(int n)
    {
        node *tmp = new node;   //allocates a new node
        tmp->data = n;
        tmp->next = NULL;

        if(head == NULL)
        {
            head = tmp;
            tail = tmp;
        }
        else
        {
            tail->next=tmp;
            tail = tail->next;
        }
    }

    node* gethead()
    {
        return head;
    }

    void display()
    {
        node *tmp;
        tmp=head;
        while(tmp!=NULL)
        {
            cout<< tmp->data <<" ";
            tmp=tmp->next;
        }
        cout<<endl;
    }

    void add_by_index(node *a, int n,int pos)
    {
        //beginning
        if(pos==0)
        {
            node *tmp = new node;
            tmp -> data = n;
            tmp -> next = head;
            head = tmp;
        }

        //Middle or last by indexing
        else
        {
            int i=0;
            node *tmp;
            tmp=a;
            while(i!=pos)
            {
                if(i==(pos-1))
                {
                    node* newNode = new node;
                    newNode->data = n;
                    newNode->next = tmp->next;
                    tmp->next = newNode;
                }
                tmp=tmp->next;
                i++;
            }
        }
    }

    //Deleting Node
    void del (node *before_del)
    {
        node* temp;
        temp = before_del->next;
        before_del->next = temp->next;
        delete temp;
    }

    void delete_position(int pos)
    {
        pos=pos+1;
        int i;
        //beginning
        if(pos==1)
        {
            node *temp=new node;
            temp=head;
            head=head->next;
            delete temp;
        }
        //middle or last
        else
        {
            node *current=new node;
            node *previous=new node;
            current=head;
            for(i=1;i<pos;i++)
            {
                previous=current;
                current=current->next;
            }
            previous->next=current->next;
        }
    }

};
int main()
{
    Linked_List a;

    a.add_last(5);
    a.add_last(12);
    a.add_last(32);
    a.add_last(43);
    a.add_last(87);
    a.add_last(85);
    a.add_last(39);
    a.add_last(98);

    a.display();

    a.add_by_index(a.gethead(),777,1);
    a.display();

    a.add_by_index(a.gethead(),999,3);
    a.display();

    a.add_by_index(a.gethead(),222,0);
    a.display();

    a.add_by_index(a.gethead(),1111,11);
    a.display();

//    a.add_by_index(a.gethead(),13333,13);
//    a.display();


    a.delete_position(3);
    a.display();

    a.delete_position(2);
    a.display();

    a.delete_position(1);
    a.display();

    a.delete_position(9);
    a.display();



    return 0;
}