creare/afisare/inserare lista simplu

#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

ifstream f("date.in");
ofstream g("date.out");

struct nod
{
    int info;
    nod *adr;
};

nod *prim;


void creare()
{
    int n,i;
    nod *p,*nou;
    while (f>>n)
        if (prim==NULL)
    {
        prim=new nod;
        prim->info=n;
        p=prim;
    }
    else
    {
        nou=new nod;
        nou->info=n;
        p->adr=nou;
        p=nou;
    }
    p->adr=NULL;
}

void inserare_inaintea_primului()
{
    nod *nou;
    cin>>nou->info;
    nou->adr=prim;
    prim=nou;
}

void inserare_dupa_ultimul()
{
  nod *p=prim,*nou;
  while (p->adr)
    p=p->adr;
  nou=new nod;
  cin>>nou->info;
  p->adr=nou;
  nou->adr=NULL;

}

void inserare_interior()
{
    int k;
     nod *p=prim,*nou;
     while (p->adr->info!=k && p->adr!=NULL)
        p=p->adr;
     nou=new nod;
     cin>>nou->info;
     nou->adr=p->adr;
     p->adr=nou;
}

int primnr(int x)
{
    int i,ok=1;
    for (i=2;i<=sqrt(x);i++)
        if (x%i==0)
        ok=0;

    if (ok==1)
        return 1;// e prim
    return 0;// nu e prim
}


void afis()
{
    nod *p=prim;
    while (p)
    {
        g<<p->info<<" ";
        p=p->adr;
    }
}


void stergere_prim_nod()
{
    nod *p=prim;
    prim=prim->adr;
    delete p;
}


void stergere_ultim_nod()
{
    nod *p=prim,*q;
    while (p->adr->adr!=NULL)
        p=p->adr;
    q=p->adr;
    delete q;
    p->adr=NULL;
}

int main()
{
    creare ();
    stergere_ultim_nod();
    afis();
    return 0;
}


//tema problema 2015

#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

ifstream f("date2.in");
ofstream g("date2.out");

struct nod
{
    int info;
    nod *adr;
};

nod *prim;

int primnr(int x)
{
    int i,ok=1;
    for (i=2;i<=sqrt(x);i++)
        if (x%i==0)
        ok=0;

    if (ok==1)
        return 1;// e prim
    return 0;// nu e prim
}

void creare()
{
    int n,i,x=2015;
    nod *p,*nou,*ins;
    while (f>>n)
        if (prim==NULL)
    {
        prim=new nod;
        prim->info=n;
        p=prim;
    }
    else
    {
        nou=new nod;
        nou->info=n;
        p->adr=nou;
        p=nou;
         if (primnr(n)==1)
            {ins= new nod;
            ins->info=x;
            p->adr=ins;
            p=ins;
            }

    }
    p->adr=NULL;
}


void afis()
{
    nod *p=prim;
    while (p)
    {
        g<<p->info<<" ";
        p=p->adr;
    }
}


int main()
{
    creare();
    afis();
    return 0;
}