[Dev-C++] stack with class

[chromatonus 7. <chr...@ho...>]

hi, may I know how to display elements and count the number of elements in a 
stack defined below, without destruction? thank you very much!





//	Program:		STACK 2
//	Objective:	To understand how a stack works as implemented by a class
//					and an array for the data
//  Last modified 11-29-01


#include <iostream.h>
#include <conio.h>

const max_stack = 100;

class stacktype
  {
    public:
  		 stacktype();
         	//	default constructor
         	//	postcondition:	initializes stack by setting TOP = 0
         void initialize();
         	//	postcondition:	erase stack by setting TOP = 0
         void push( int );
         	//	postcondition:	If the stack is not full,
            //							increase TOP by 1 , then
            //							put info into DATA[TOP]
         int pop();
         	//	postcondition:	If the stack is not empty,
           	//                 	put DATA[TOP] into x,
            //							decrease TOP by 1,
            //							return x
        	bool is_empty();
         	//	postcondition:	Return true if stack is empty, false otherwise.
         bool is_full();
         	//	postcondition:	Return true if stack is full, false otherwise.
    private:
    		int mydata[max_stack];
         int mytop;			//	subscript of the top of the stack
  };


//==============================================================================
//============================== Free functions 
================================
//==============================================================================

void display_top( stacktype );
	//	precondition:	send in stack
   //	postcondition:	display, without destruction, the value in data[top]
void display_stack( stacktype );
	//	precondition:	send in stack
   //	postcondition:	display, without destruction, the values of all the
   //						elements in the stack, in the order entered.
int count_values( stacktype );
	//	precondition:	send in stack
   //	postcondition:	return the number of data pieces
int menu();
	//	postcondition:	initial screen.  Display options, allow user to enter
   //						choice and return this value

//==============================================================================
//============================== Implementation 
================================
//==============================================================================

stacktype::stacktype()
{
   mytop = 0;
}
void stacktype::initialize()
{
   mytop = 0;
}
bool stacktype::is_empty()
{
   if( mytop == 0 )
      return true;
   else
      return false;
}
bool stacktype::is_full()
{
   if( mytop == 99 )
      return true;
   else
      return false;
}
void stacktype::push( int x )
{
	if( is_full() == false )
   {
      mytop++;
      mydata[mytop] = x;
   }
}
int stacktype::pop()
{
   if( is_empty() == false )
   {
      int x = mydata[mytop];
      mytop--;
      return x;
   }
}


//==============================================================================
//============================== Client Program 
================================
//==============================================================================

int menu()
{
   int choice;
   cout<< "STACK EDITOR MENU OPTIONS" << "\n";
   cout<< "1.  Create new stack" << "\n";
   cout<< "2.  Add elements to stack" << "\n";
   cout<< "3.  Delete elements from stack" << "\n";
   cout<< "4.  Display top element in stack " << "\n";
   cout<< "5.  Display whole stack in the order entered" << "\n";
   cout<< "6.  Count numbers of elements in stack" << "\n";
   cout<< "7.  Exit" << "\n" << "\n";
   gotoxy(0,8);
   cout<< "choice? ";
   cin>> choice;
   return(choice);
}

int main()
{
   stacktype S, T;
   int choice, x, i;
   choice = menu();
   while( choice != 7 )
   {
      switch( choice )
      {
         case 1:  S.initialize();
                  gotoxy(0,8);
                  cout<< "choice? ";
                  cin>> choice;
                  break;

         case 2:  gotoxy(0,10);
                  while(S.is_full() == false)
                  {
                     cout<< "number to insert?  ";
                     cin>> x;
                     S.push(x);
                  }
                  gotoxy(0,8);
                  cout<< "choice? ";
                  cin>> choice;
                  break;

         case 3:  gotoxy(0,10);
                  S.pop();
                  gotoxy(0,8);
                  cout<< "choice? ";
                  cin>> choice;
                  break;

         case 4:  gotoxy(0,12);
                  display_top(S);
                  gotoxy(0,8);
                  cout<< "\n" << "choice? ";
                  cin>> choice;
                  break;

         case 5:  display_stack(S);
                  gotoxy(0,8);
                  cout<< "choice? ";
                  cin>> choice;
                  break;

         case 6:  count_values(S);
                  cout<< i;
                  gotoxy(0,8);
                  cout<< "choice? ";
                  cin>> choice;
                  break;

         case 7:  exit();
                  break;

         choice = menu();
      }
   }
}

void display_top( stacktype S )
{
   S.pop();
   cout<< S.mytop;
}

void display_stack( stacktype S )
{
   stacktype T;
   while( S.mytop != 0 )
   {
      S.pop();
      T.push(S.mytop);
   }
   while( T.mytop != 0 )
   {
      cout<< T.pop();
      T.mytop--;
   }
}

int count_values( stacktype S )
{
   int i = 0;
   if(S.mytop != 0)
   {
      while(S.mytop != 0)
      {
         S.pop();
         i++;
      }
      return i;
   }
   ///////     ???????
}

int exit()
{
   return x;
}

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