//Header file for Stack class

const MaxStack = 100;
const True = 1;
const False = 0;

typedef char StackElement;

class Stack
{
  protected:
    StackElement Items[MaxStack];
    int Top;

  public://methods
    Stack();
    void Push(StackElement X,       //input - data to insert
	      int &Success);        //output - program flag
    void Pop(StackElement &X,       //output - data removed
	     int &Success);         //output - program flag
    void Retrieve(StackElement &X,  //output - data retrieved
		  int &Success);    //output - program flag
    int IsEmpty();
    int IsFull();
};