#include<iostream.h>
struct STACK{
  char data;
  STACK *link;
  };
STACK *topptr;
void ciptastackkosong(){
  topptr= NULL;
  }
  void push(char nilai){
  STACK *newptr;
 
  newptr = new STACK;
  newptr->data = nilai;
  newptr->link = NULL;
 
  newptr->link = topptr;
  topptr = newptr;
  cout<<topptr->data;
  }
 
  void pop(){
  STACK *temptr;
  if (topptr == NULL)
  cout<< "STACK KOSONG";
  else{
  temptr = topptr;
  cout<<endl<<"data yang akan keluar\t"<<topptr->data;
  topptr = topptr->link;
  delete temptr;}}
 
  void popALL(){
  while (topptr!=NULL)
  pop();
  cout<<"\nData telah terhapus";}
  int main(){
  ciptastackkosong();
  push('K');
  push('A');
  push('T');
  push('A');
  push('K');
  pop();
  popALL();

  }

pre = +ab

post = ab+