package balik;		//musi se prelozit do dir. balik
import java.io.*;
public class Stack_class { //kdyz je public, tak
	//je v samost. soubor, ten musi mit stejne jmeno
   private int [ ] stack_ref;
   private int max_len, 
           top_index;
   public Stack_class() { //constructor
      stack_ref = new int [100];
      max_len = 99;
      top_index = -1;
   }
   public void push(int number) {
      if (top_index == max_len)
         System.out.println("error in push, stack is full");
      else stack_ref[++top_index] = number;
   }
   public void pop() {
      if (top_index == -1)
         System.out.println("error in pop, stack is empty");
      else --top_index;
   }
   public int top() {return (stack_ref[top_index]);}
   public boolean empty() {return (top_index == -1);}
}