bugs of a debugger

/**************************************************************	
	Author: Arun Vishnu M V
	Web: www.arunmvishnu.com
	Description: C++ Program to implement a stack using linked list.
***************************************************************/
#include<conio.h>   	
#include<iostream.h> 
#include<process.h>  
#include<malloc.h>  
 
 
//   Creating a NODE Structure
struct node
{
   int data;
   struct node *next;
};
 
// Creating a class STACK
class stack
{
   struct node *top;
   public:
      stack() // constructure
      {
	 top=NULL;
      }
      void push(); // to insert an element
      void pop();  // to delete an element
      void show(); // to show the stack
};
// PUSH Operation
void stack::push()
{
   int value;
   struct node *ptr;
   cout<<"\nPUSH Operation\n";
   cout<<"Enter a number to insert: ";
   cin>>value;
   ptr=new node;
   ptr->data=value;
   ptr->next=NULL;
   if(top!=NULL)
      ptr->next=top;
   top=ptr;
   cout<<"\nNew item is inserted to the stack!!!";
   getch();
}
 
// POP Operation
void stack::pop()
{
   struct node *temp;
   if(top==NULL)
   {
      cout<<"\nThe stack is empty!!!";
      getch();
      return;
   }
   temp=top;
   top=top->next;
   cout<<"\nPOP Operation........\nPoped value is "<<temp->data;
   delete temp;
   getch();
}
 
// Show stack
void stack::show()
{
   struct node *ptr1=top;
   cout<<"\nThe stack is\n";
   while(ptr1!=NULL)
   {
      cout<<ptr1->data<<" ->";
      ptr1=ptr1->next;
   }
   cout<<"NULL\n";
   getch();
}
 
// Main function
int main()
{
   clrscr();
   stack s;
   int choice;
   while(1)
   {
      cout<<"\n-----------------------------------------------------------";
      cout<<"\n\t\tSTACK USING LINKED LIST\n\n";
      cout<<"1:PUSH\n2:POP\n3:DISPLAY STACK\n4:EXIT";
      cout<<"\nEnter your choice(1-4): ";
      cin>>choice;
      switch(choice)
      {
       case 1:
	  s.push();
	  break;
       case 2:
	  s.pop();
	  break;
       case 3:
	  s.show();
	  break;
       case 4:
	  exit(0);
	  break;
       default:
	  cout<<"Please enter correct choice(1-4)!!";
	  getch();
	  break;
       }
   }
   return 0;
}
 
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