// Implementation of a Stack as a linked list
//purpose: To implement an array of list in a certain Stack


public class LLStack{
private java.util.LinkedList list=nw java.util.LinkedList();
public LLStack(){
}
public void clear(){
list.clear();
}
public boolean isEmpty(){
return list.isEmpty();
}
public Object topEl(){
if(isEmpty())
throw new java.util.EmptyStackException();
return list.getLast();
}
public Object pop(){
if(isEmpty())
throw new java.util.EmptyStackException();
return list.removeLast();
}
public void push(Object el){
list.addLast(el);
}
public String toString(){
return list.toString();
}
}

[Data structures and algorithms in Java 2nd Edition by: Adam Drozdek]