Списки емое)

#include <iostream>
#include <fstream>
#include<iomanip>
using namespace std;
struct node
{
    int data;
    node* next;
};
void create_list (node* &top,int n)
{
    node* p;
    top = new node;
    top = NULL;
    for (int i=0;i<n;i++)
    {
        p=new node;
        cin>>p->data;
        p->next=top;
        top=p;
    }
}
void show_list (node* &top)
{
    node* p;
    p=top;
    while(p)
    {
        cout<<p->data;
        p=p->next;
    }
    cout<<endl;
}
void push (node* &top,int data)
{
    node* p;
    p = new node;
    p->data = data;
    p->next = top;
    top=p;
}
node* previous (node* top,node* p)
{
    node* pr,*q;
    q=top;
    pr = NULL;
    while (q!=p&&q)
    {
        pr=q;
        q=q->next;
    }
    if (q==p)
    {
        return pr;
    }
    return NULL;

}
node* find_adress (node* top,int x)
{
    node* p = top;
    while (p!=NULL)
    {
        if (p->data == x) {
            return p;

        }
          p=  p->next;
    }
    return NULL;
}
void insert_list_after(node* top,node* &q,int x)
{
    node *p;
    p = new node;
    p->data = x;
    p->next= q->next;
    q->next=p;
}
void insert_list_before (node* top,node* &q,int x)
{
    node* p,*r ;
    p = new node;
    r=previous(top,q);
    if (q==top) push(top,x);
    else {
    p->data=x;
    p->next=r->next;
    r->next=p;
        }
    }

int main ()
{
    int n;
    int d1;
    int d2;
    int d3;
    node* list;
    node* pt = NULL;
    cout<<"Enter n: ";
    cin>>n;
    create_list(list, n);
    show_list(list);
    cout<<"Enter a num to find: ";
    cin>>d1;
    pt = find_adress(list, d1);
    if (pt)
        cout<<"Data: "<<pt->data<<endl;
    cout<<"Enter a num to insert after: ";
    cin>>d2;
    insert_list_after(list, pt, d2);
    cout<<"Enter a num to insert before: ";
    cin>>d3;
    insert_list_before(list, pt, d3);
    show_list(list);
}