#ifndef STACKA_H
#define STACKA_H

// Header file StackA.h for the ADT Stack.
// Array-based implementation.
// *********************************************************

template <typename StackItem>
class Stack 
{

public:

// constructors and destructor:

   Stack(); // default constructor
   // copy constructor and destructor are
   // supplied by the compiler

// Stack operations:

   // Determines whether a Stack is empty.
   // Precondition: None.
   // Postcondition: Returns true if the Stack is empty;
   // otherwise returns false.
   bool isEmpty() const;

   // Adds an item to the top of a Stack.
   // Precondition: newItem is the item to be added.
   // Postcondition: If the insertion is successful, newItem
   // is on the top of the Stack.
   // Returns true if successful, false otherwise.
   bool push(const StackItem &newItem);

   // Removes the top of a Stack.
   // Precondition: None.
   // Postcondition: If the Stack is not empty, the item
   // that was added most recently is removed. However, if
   // the Stack is empty, deletion is impossible.
   // Returns true if successful, false otherwise.
   bool pop();

   // Retrieves and removes the top of a Stack.
   // Precondition: None.
   // Postcondition: If the Stack is not empty, StackTop
   // contains the item that was added most recently and the
   // item is removed. However, if the Stack is empty,
   // deletion is impossible and StackTop is unchanged.
   // Returns true if successful, false otherwise.
   bool pop(StackItem &StackTop);

   // Retrieves the top of a Stack.
   // Precondition: None.
   // Postcondition: If the Stack is not empty, StackTop
   // contains the item that was added most recently.
   // However, if the Stack is empty, the operation fails
   // and StackTop is unchanged. The Stack is unchanged.
   // Returns true if successful, false otherwise.
   bool getTop(StackItem &StackTop) const;

private:
   static const int MAX_STACK  = 100;

   StackItem items[MAX_STACK]; // array of Stack items
   int       top;              // index to top of Stack 
};

#include "StackA.cpp"
#endif