package com.coding.basic;
public class Stack<E> {
private ArrayList<E> elementData = new ArrayList();
public void push(E o){
elementData.add(o);
}
/**
* 移除栈顶并返回他
* @return
*/
public E pop(){
return elementData.remove(elementData.size()-1);
}
/**
* 得到栈顶元素
* @return
*/
public E peek(){
return elementData.get(elementData.size()-1);
}
public boolean isEmpty(){
return elementData.isEmpty();
}
public int size(){
return elementData.size();
}
}