#include <iostream>
#include <ctime>
#include <cstdlib>

using namespace std;

struct Nod
{
    int info;
    Nod *leg;
};


struct Lista                            /// Simplu inlantuita
{
    Nod *L;

    void Inserare1(int x)               /// Inserare la inceput
    {
        Nod *p;
        p = new Nod;
        p -> info = x;
        p -> leg = L;
        L = p;
    }

    void Inserare2(Nod *p, int x)       /// Inserare dupa nodul de adresa memorata in p
    {
        Nod *q;
        q = new Nod;
        q -> info = x;
        q -> leg = p -> leg;
        p -> leg = q;
    }

    ///     Insereaza dupa al k-lea nod
    /// un nou nod cu informatia x;
    /// Daca lista are mai putin de
    /// k noduri, inserarea se face
    /// la sfarsitul listei.
    void Inserare3(int k, int x)
    {
        Nod *p, *q;
        for(p = L; (k > 1) && (p != NULL); p = p -> leg)
        {
            k--;
            q = p;
        }
        if(p == NULL) /// Inserez dupa q
            Inserare2(q, x);
        else /// Inserez dupa p
            Inserare2(p, x);
    }

    void Parcurgere()                   /// Parcurgerea listei
    {
        for(Nod *p = L; p != NULL; p = p -> leg)
            cout << p -> info << " ";
        cout << "\n";
    }

    void Init()                         /// Initializarea listei vide
    {
        L = NULL;
    }

    void Sterge1()                      /// Stergerea primului nod
    {
        if(L = NULL) return;
        Nod *p;
        p = L;
        L = p -> leg;
        delete p;
    }

    void Sterge2(Nod *p)                /// Stergerea nodului dupa nodul de adresa memorata p
    {
        Nod *q;
        q = p -> leg;
        p -> leg = q -> leg;
        delete q;
    }

    Nod *Cautare(int x)                 /// Cautarea valorii x in lista si returnarea pointer-ului
    {
        Nod *p;
        for(p = L; p != NULL; p = p -> leg)
            if(p -> info == x)
                return p;
        return NULL;
    }

    void ParcDS(Nod *p) /// Parcurgerea de la dreapta la stanga a nodurilor listei
    {
        if(p != NULL)
        {
            ParcDS(p -> leg);
            cout << p -> info << " ";
        }
    }
};

void InserNr(Lista a)
{
    for(Nod *p = a.L; p != NULL; p = p -> leg)
        if(p -> info % 2 == 0)
            a.Inserare2(p, p -> info + 1);
}

void Elim5(Lista a)
{
    while(a.L != NULL && a.L -> info % 5 == 0) a.Sterge1();
    for(Nod *p = a.L; p -> leg != NULL; )
        if(p -> leg -> info % 5 == 0)
            a.Sterge2(p);
        else
            p = p -> leg;
}

void AfisCheie(Lista a, int k)
{
    Nod *p = a.L;
    for(p = a.L; k > 1 && p != NULL; p = p -> leg)
        k--;
    if(p == NULL) cout << "Nu se este."
    cout << p -> info;
}

void AfisCheieDS(Lista a, int k)
{
    Nod *q , *p;
    q = p = a.L;
    for(int i = 1; i <= k; i++)
        p = p -> leg;

    while(p != NULL)
    {
        q = q -> leg;
        p = p -> leg;
    }

    cout << q -> info;
}

int main()
{

    Lista a;
    a.Init();

    srand(time(0));
    for(int i = 1; i <= 10; i++)
        a.Inserare1(rand() % 100 + 1);

    a.Parcurgere();

    /* -1-
    InserNr(a);
    a.Parcurgere();
    */

    /*
    Elim5(a);
    a.Parcurgere();
    */

    /// Sa se afiseze cheiea celui de-al k-lea nod
    /// Daca lista are mai putin de k noduri, se va afisa un mesaj
    //AfisCheie(a, 3);

    /// De la DR la ST
    AfisCheieDS(a, 3);

    return 0;
}