pedro listy

#include <iostream>
using namespace std;

struct Node {
    Node(int n)
    {
        this->n = n; // musimy użyć this->n aby wskazać że chcemy ustawić n naszego obiektu równe przekazanej wartosci n
        next = NULL;
    }

    int n;
    Node *next;
};

struct List {
    Node *head;
    Node *tail;

    List() // konstruktor
    {
        head = NULL;
        tail = NULL;
    }

    void add(int n){
        Node *node = new Node(n); //wywołujemy konstruktor z paramterem n ktry ustawia n noda na n
        //node->n = n;
        //node->next = NULL; //ponieważ utwożyliśmy konstruktor do node ten kod jest zbedny ponieważ robi to za nas konstruktor
        if (head == NULL) {
            head = node;
            tail=head;
        }
        else {
            tail->next = node;
            tail = tail->next;
        }
    }

    void display(){
        Node *node = head; //=head bo na *node bylby losowy smiec
        while (node != NULL) {
            cout << "n = " << node->n << endl;
            node = node->next;
        }
    }

    void delete_el(int n) { //jeden element znaleziony usuwa
        Node *node = head;
        Node *previous = head;
        while (node != NULL) {
            if (node->n == n) {
                if (node == head) {
                    Node *tmp = head->next;
                    delete node;
                    head = tmp;
                }
                else {
                    previous->next = node->next;
                    delete node;
                }
                break;
            }
            previous = node;
            node = node->next;
        }
    }

    void delete_firstel() {
        Node *node = head;
        Node *tmp = head->next;
        delete head;
        head = tmp;
    }

    void delete_lastel() {
        Node *node = head;
        Node *tmp = head;
        while (node != NULL) {
            if (node->next == NULL) {
                if (node == head) {
                    delete head;
                    head = NULL;
                }
                else {
                    delete node;
                    tmp->next = NULL;
                    tail = tmp;
                }
                break;
            }
            tmp = node;
            node = node->next;
        }
    }

};


struct A
{
    int a;
    int b;
    int c;
    A()
    {
        a = 0;
        b = 1;
        c = 2;
    }
};
int main()
{

    List list;//zadeklarowanie listy
    for (int i=1;i<=10;i++)
        list.add(i); //dodanie elementu do listy
    list.display();
    list.delete_lastel();
    list.add(16);
    list.display();
    while (true);
}