栈是一种特殊的线性表,只能在一端进行操作

栈的接口设计
public class Stack<E> {
private List<E> list=new ArrayList<>();
public int size(){
return list.size();
}
public boolean isEmpty(){
return list.isEmpty();
}
public void push(E element){
list.add(element);
}
public E pop(){
return list.remove(list.size()-1);
}
public E top(){
return list.get(list.size()-1);
}
}