ASD Coada (Stiva) cu clasa bazata pe lista

#include <iostream>

using namespace std;

struct Node
{
    int info;
    Node* next;
};

class Lista
{
public:
    Node* head;
    int counter = 0;

    Lista()
    {
        head = NULL;
    }

    void printList();
    void insert(int val, int pos);
    void deleteByPos(int pos);
    void reverse();
    void deleteList();
    int getElement(int pos);

};


void Lista::printList()
{
    for (Node* p = head; p != NULL; p = p->next)
        {
            cout << p->info;

            if (p->next == NULL)
                cout<<". ";
            else
                cout<<", ";
        }

    cout<<"\n";

}

int Lista::getElement(int pos)
{
    Node *temp = head;
    int i = 0;
    while (temp->next != NULL && i != pos - 1)
        {
            temp = temp->next;
            i++;
        }

    if (i == pos - 1)
        return temp->info;
    else
        return -1; // pozitia nu exista in lista
}


void Lista::insert(int val, int pos)
{
    Node *p = new Node;
    p->info = val;
    p->next = NULL;
    counter++;

    if (head == NULL) // inserare lista goala
    {
        head = p;
        return;
    }

    if (pos == 0) //inserare la inceput
    {
        p -> next = head;
        head = p;
        return;
    }

    int i = 0; //inserare dupa o anumita pozitie
    Node* temp;
    temp = head;

    while(temp->next != NULL && i != pos - 1) //parcurgem lista pana pe pozitia pos - 1
    {
        temp = temp -> next;
        i++;
    }

    p->next = temp->next;
    temp->next = p;

}

void Lista::deleteByPos(int pos)
{
    counter--;

    if (head == NULL) //daca lista e goala
        return;

    if (pos == 0) //daca stergem primul element
        {
            Node* p = head;
            delete p;

            head = head -> next;
            return;
        }

    int i = 0; //stergere la o anumita pozitie
    Node* temp;
    temp = head;

    while(temp->next != NULL && i != pos - 1) //parcurgem lista pana pe pozitia pos - 1
    {
        temp = temp -> next;
        i++;
    }

    Node* p;
    p = temp->next;
    delete p;

    if(temp->next->next != NULL)
        temp->next = temp->next->next;
    else
        temp->next = NULL;

}

void Lista::reverse()
{
    Node *current = head, *prev = NULL, *urm = NULL;

    while (current != NULL)
    {
        urm = current->next;

        current->next = prev;

        prev = current;
        current = urm;
    }

    head = prev;
}

void Lista::deleteList()
{
    Node *p;
    p = head;

    while (head != NULL)
    {
        head = head->next;
        delete p;

        p = head;

        counter--;
    }
}

class Coada
{
    Lista l;
public:
    void push(int x);
    void pop();
    int size();
    int top();

    void printCoada();
    void deleteCoada();
};

void Coada::printCoada()
{
    l.printList();
}

void Coada::push(int x)
{
    l.insert(x,l.counter);
}

void Coada::pop()
{
    l.deleteByPos(0);
}

int Coada::size()
{
    return l.counter;
}

int Coada::top()
{
    return l.getElement(l.counter);
}

void Coada::deleteCoada()
{
    l.deleteList();
    return;
}

int main()
{
    Coada c;
    c.push(1);
    c.push(5);
    c.push(10);
    c.push(15);
    c.pop();
    c.printCoada();
    cout<<c.top();

    return 0;
}