arbore binar creare+parcurgeri

#include<iostream>
#include<fstream>
using namespace std;
ifstream f("e:\\info\\arborebinar.txt");
struct nod
{   int info;
    nod *s,*d;
};
nod *r;
void creare(nod *&r)
{   int n;
    f>>n;
    if (n==0)
        r=NULL;
    else
    {   r=new nod;
        r->info=n;
        creare(r->s);
        creare(r->d);
    }
}
void rsd(nod *r)//preordine parcurgere radacina stanga dreapta
{   if(r!=NULL)
    {   cout<<r->info<<" ";
        rsd(r->s);
        rsd(r->d);
    }
}
void srd(nod *r) //inordine parcurgere stanga radacina dreapta
{   if(r!=NULL)
    {   srd(r->s);
        cout<<r->info<<" ";
        srd(r->d);
    }
}
void sdr(nod *r) //post ordine parcurgere stanga dreapta radacina
{   if(r!=NULL)
    {   sdr(r->s);
        sdr(r->d);
        cout<<r->info<<" ";
    }
}
int main()
{   creare(r);
    cout<<"rsd=";
    rsd(r);
    cout<<endl;
    cout<<"srd=";
    srd(r);
    cout<<endl;
    cout<<"sdr=";
    sdr(r);

}
f:1 2 4 0 7 8 0 0 0 0 3 5 9 0 0 10 0 0 6 0 11 0 0