class stack
{
    public:
            stack();         //constructor
            ~stack() {delete [] SArray;}         //destructor deletes the array

    //class methods
            void Push(int S);
            void Pop();
            int Top();
            // IsEmpty() tests to see if the TopOfStack equals -1 and returns true or false.
            int IsEmpty() {return TopOfStack == -1;}
 
            // IsFull() tests to see if the TopOfStack is at position Maxsize-1
            // and returns either true or false
            int IsFull(){return TopOfStack == Maxsize-1;}

            // MakeEmpty() sets the TopOfStack to equal -1.
            void MakeEmpty() {TopOfStack = -1;}

    private:
            int Maxsize; // the size of the stack
            int TopOfStack; // index for the top of the stack
            int *SArray; // SArray is a pointer to an integer
};

// constructor initialises the private members of stack
// array SArray is allocated dynamically using new and is of size Maxsize

stack::stack()
{
    Maxsize = 10;
    TopOfStack = -1;
    SArray = new int[Maxsize];
}

// Push places the integer S on the top of the stack

void stack::Push(int S)
{
    if(!IsFull())
        SArray[++TopOfStack] = S; //increment TopOfStack and place S in that array position
    else
        cout<<"No room on stack\n";
}

// Pop decrements the TopOfStack index, thus indicating a new TopOfStack

void stack::Pop()
{
    if(IsEmpty())
        cout<<"Stack empty, nothing to pop\n";
    else
        TopOfStack--;
}

// Top returns the top element on the stack

int stack::Top()
{
    return SArray[TopOfStack];
}