class stack
{
    int *arr;
    int size;
    int maxsize;


public:

    void push(int x);
    void push(int array[],int arrsize);

    void push(stack*,int );
    int pop();
    int top();

    stack();//default constructor
    stack(int);//parameterized constructor
    stack(const stack &obj);
    void expand_mem();
    void shrink_mem();

    ~stack();
    int getsize(){return size;}
    void setsize(int x){size=x;}




};
stack::stack()
{
    cout<<"Default Constructor Constructing..."<<endl;
    size=0;
    maxsize=5;
    arr= new int[maxsize] ;
    if (!arr)
    {
        cout << "Memory allocation failed"<<endl;
    }


}
stack::stack(int maxsize)
{
    cout<<"Parameterized Constructor Constructing..."<<endl;
    size=0;

    this->maxsize=maxsize;

    arr= new int[maxsize] ;
    if (!arr)
    {
        cout << "Memory allocation failed"<<endl;
    }


}
stack::stack(const stack &obj)
{
    cout<<"Copy Constructor Constructing..."<<endl;

    size=obj.size;
    maxsize=obj.maxsize;
    arr=new int[obj.size];
    for(int i=0;i<size;i++)
    {
        arr[i]=obj.arr[i];
    }

}


void stack::push(int x)
{
    if(size==maxsize)
    {
        expand_mem();
    }
    arr[size]=x;
    size++;
}
void stack::push(int array[],int arrsize)
{
    int temp_size;
    temp_size=size;
    for(int i=0;i<arrsize;i++)
    {
        if(size==maxsize)
        {
            expand_mem();

        }
        arr[temp_size+i]=array[i];
        //cout<<arr[temp_size+i]<<endl;
        size++;
    }


}
void stack::push(stack* tempStack,int stacksize)
{
    int temp_size;
    temp_size=size;
    for(int i=0;i<stacksize;i++)
    {
         if(size==maxsize)
        {
            expand_mem();


        }
        arr[temp_size+i]=tempStack->pop();
        size++;
    }


}
void stack::expand_mem()
{
    cout<<"Memory is expanding by 10 "<<endl;
    maxsize=maxsize+10;
    int *temp_arr;
    temp_arr=new int[maxsize];
    for(int i=0; i<maxsize; i++)
        {
            temp_arr[i]=0;
        }

    for(int i=0; i<size; i++)
        {
            temp_arr[i]=arr[i];
        }

        delete[] arr;
        arr=new int[maxsize];
        for(int i=0; i<maxsize; i++)
        {
            arr[i]=temp_arr[i];
        }

        delete[] temp_arr;

}


void stack::shrink_mem()
{
    cout<<"memory is shrinking by 10"<<endl;
   maxsize=maxsize-10;
    int *temp_arr;
    temp_arr=new int[maxsize];
    for(int i=0; i<maxsize; i++)
        {
            temp_arr[i]=0;
        }
    for(int i=0; i<size; i++)
        {
            temp_arr[i]=arr[i];
        }
        delete[] arr;
        arr=new int[maxsize];
        for(int i=0; i<maxsize; i++)
        {
            arr[i]=temp_arr[i];
        }
        delete[] temp_arr;

}



int stack::pop()
{
    if(size==0)
    {

        return -1;
    }
    int popvalue;
    popvalue=arr[size-1];
    if((maxsize-size+1)>=10)
       {

           shrink_mem();

       }
       //cout<<size<<endl;

        size--;
        //cout<<size<<endl;
    return popvalue;
}
int stack::top()
{
    if(size==0)
    {

        return -1;
    }

    return arr[size-1];
}




stack::~stack()
 {
     delete[] arr;
     cout<<"Memory has been dealocated :)"<<endl;
 }