#include <iostream.h>
#include <string.h>

const int MAXCHARS = 30;
const int TRUE = 1;
const int FALSE = 0;

// class declaration
// preconditions: requires that MAXCHARS, the maximum size of a name, be defined
//              : requires that TRUE be defined as a nonzero integer
//              : requires that FALSE be defined as 0

class Stack
{
  private:
    struct NameRec
    {
      char name[MAXCHARS];
      NameRec *prioraddr;
    };
    NameRec *top;     // top-of-stack pointer

  public:
    Stack();  // constructor
    void push(char *);
    char *pop();
    int isempty();
};

// implementation section
Stack::Stack()  // constructor
{
  top = NULL;
}

void Stack::push(char *newname)
{
  NameRec *newAddr;  // a pointer to a NameRec

  newAddr = new (NameRec);
  if (newAddr == NULL)
   {
     cout <<"\nNo more storage allocation space"
       << "\nThe last name has not been entered on the stack"
       << endl;
   }
   else
   {
     strcpy(newAddr->name, newname);  // store the name
     newAddr->prioraddr = top;       // store the address
     top = newAddr;                  // update top
   }

  return;
}

char *Stack::pop() // return a pointer to a name
{
  NameRec *tempAaddr;
  char name[MAXCHARS];

  strcpy(name,top->name);  // retrieve the name from top-of-stack
  tempAddr = top->prioraddr;  // retrieve prior address
  delete(top);                 // free record's memory space
  top = tempAddr;        // update the top-of-stack pointer
  return name;
}

int Stack::isempty()
{
  if (top == NULL)
    return TRUE;
  else
    return FALSE;
}

int main()
{
 char newname[MAXCHARS];
 Stack namestack;   // define a Stack object

 cout << "Enter as many names as you wish, one per line"
      << "\nTo stop entering names, enter a single x\n";
 while (1)
 {
   cout << "Enter a name: ";
   cin.getline(newname,MAXCHARS);
   if (strcmp(newname,"x") == 0)
     break;
   else
     namestack.push(newname);
 }

   // pop and display names from the stack
  cout << "\nThe names popped from the stack are:\n";
  while (!namestack.isempty())
  {
    strcpy(newname,namestack.pop());
    cout << newname << endl;
  }

  return 0;
}