Linked lists

In link list a structure is declared as head and it has a next pointer which points to next item in the list and similarly all items have a next pointer.The next pointer of the last element points to NULL.The program goes as long as user does not input n.The user has two options whether to insert or delete from the list.In insert we declare a temporary variable temp which contains the number to insert which is done by putting temp->next=head and head=temp which means that now head points to temp and temp points to the element which was previously head.Delete is done by simply putting head equal to its next element.

#include<iostream>
using namespace std;
struct Linkedlist
{
    int a;
    struct Linkedlist* next;
};
LinkedList* head;
void insert(int num)
{
    Linkedlist* temp;
    temp= new Linkedlist;
    temp->a=num;
    if(head!=NULL)
    {
        temp->next=head;
    }
    else
    {
        temp->next=NULL;
    }
    head=temp;
}
int del()
{
    if(head==NULL)
    {
        return -1;
    }
    Linkedlist *temp;
    temp=head;
    head=head->next;
    return temp->a;
}
int main()
{
    head=new Linkedlist;
    char choice;
    int c,num;
    do
    {
        cout<<"1:Insert an element\n";
        cout<<"2:Delete an element\n";
        cin>>c;
        switch(c)
        {
            case 1:
                cout<<"Enter number to insert:";
                cin>>num;
                insert(num);
                cout<<"\n";
                break;
            case 2:
                num=del();
                if(num!=-1)
                {
                    cout<<"The deleted number is:"<<num<<"\n";
                }
                else
                {
                    cout<<"list is empty\n";
                }
                break;
            default:
                cout<<"Wrong choice\n";
        }
        cout<<"Do you want to continue?(y/n)\n";
        cin>>choice;
    }while(choice=='y');
    return 0;
}

OUTPUT: