#include <iostream>

using namespace std;
class ArrayList{
public:

    ArrayList(int p){

        razmer = p;
        mass = new int[razmer];
        obnulit(mass, razmer);
    }

    void obnulit(int mass[], int razmer){

        for(int i = 0; i < razmer; i++){

            mass[i] = 0;
        }
    }
    void set(int position, int value){

       if(position>=count)
            cout<<"Net takogo elementa"<<endl;
        else
        mass[position] = value;
    }

    int get(int position){

        if(position>=count) return 0;
        return mass[position];
    }
    void newSpace(){
        razmer*=2;

        int* k = new int[razmer];
        obnulit(k, razmer);

        for(int i = 0; i < razmer/2 ; i++){
            k[i] = mass[i];
        }
        delete mass;
        mass = k;
    }
    void push(int value){
        if(count==razmer-1){
            newSpace();
        }
        mass[count] = value;
        count++;
    }

    ~ArrayList(){
        delete[] mass;
    }

     int pop(){
        count--;
        int i = mass[count];

        return i;
    }
    int quantity(){
        return count;
    }
private:
    int count = 0;
    int razmer;
    int* mass;
};
int main()
{
      ArrayList d(1);
    int x = -1;
    int value;
    int position;

    cout << "1 dlya dobavlenia elementa" << endl
    << "2 dlya dlya uborki" << endl
    << "3 dlya polucheniya elementa" << endl
    << "4 dlya izmeneniya elementa" << endl
    << "0 dlya vihoda" << endl;

    while (x !=0){

        cout<<endl<<"Vvedi nomer: ";
        cin>>x;
        switch(x){
            case 1: cout << "vvedi chislo ";
                    cin >> value;
                    d.push(value); break;
            case 2: cout<<d.pop()<<endl;break;

            case 3:
                    cout << "vvedi positsiyu: ";
                    cin >> position;

                    cout<< d.get(position)<<endl; break;

            case 4: cout <<  "vvedi positsiyu: ";
                    cin >>  position;
                    cout <<  "vvedi chislo: ";
                    cin >> value;

                    d.set(position, value); break;
        }
        cout << "Spisok seychas: ";
        for(int i = 0; i < d.quantity(); i++)
            cout<<d.get(i);

        if(d.quantity() == 0)
            cout<<"pust";
    }
}