stergere lista toate elem cu o anum prop

#include <fstream>
#include <iostream>

using namespace std;

ifstream f("date.in");

struct nod
{
    int info;
    nod *adr;
};
nod *prim;
void creare()
{
    int x;
    nod *nou,*p;
    while(f>>x)
    {
        if(prim==NULL)
        {
            prim=new nod;
            prim->info=x;
            p=prim;
        }
        else
        {
            nou=new nod;
    nou->info=x;
            p->adr=nou;
            p=nou;
        }
    }
        p->adr=NULL;
}
void perfect()
{
    int i;
    nod *p=prim,*q,*r;
    if(p->info%7==0)
    {prim=prim->adr;
        delete p;
    }
    p=prim;
    while(p->adr!=NULL)
    {
     if(p->adr->info%7==0)
     {
         q=p->adr;
         r=p->adr->adr;
         p->adr=r;
         delete q;
     }
     else
        p=p->adr;
    }
}
void afis()
{ int i;
    nod *p=prim;
    while(p)
    {
        cout<<p->info<<" ";
        p=p->adr;
    }
}
int main()
{
    creare();
    perfect();
    afis();
}