3 list

#include <iostream>

using namespace std;
struct node
{
    int data;
    node *next;
};
void add(node*&head,node*&tail,int item)
{
    node *newNode=new node;
    newNode->data=item;
    if(head==NULL)
    {
        head=tail=newNode;
        newNode->next=NULL;
    }
    else
    {
        newNode->next=head;
        head=newNode;
    }
}
void dis(node *&head)
{
    node *temp=head;
    if(head==NULL)
    {
        cout<<"Error";
        return;
    }
    else
        while(temp!=NULL)
    {
        cout<<temp->data<<endl;
        temp=temp->next;
    }
}
int main()
{
    node *head,*tail,*head1,*tail1,*head2,*tail2;
    head=tail=head1=tail1=head2=tail2=NULL;
    int i,item;
    for(i=0;i<5;i++)
    {
        cout<<"Enter item ";
        cin>>item;
        add(head,tail,item);
    }
    cout<<"\ncin list 2\n";
    for(i=0;i<5;i++)
    {
        cout<<"Enter item ";
        cin>>item;
        add(head1,tail1,item);
    }
    cout<<"\ncin list 3\n";
    for(i=0;i<5;i++)
    {
        cout<<"Enter item ";
        cin>>item;
        add(head2,tail2,item);
    }
    dis(head);
    dis(head1);
    dis(head2);
    return 0;
}