package com.github.wdn.coding2017.basic;
/**
* 使用list实现比较简单
* 可以考虑使用其它结构
*/
public class Stack {
private ArrayList elementData = new ArrayList();
public void push(Object o){
elementData.add(o);
}
public Object pop(){
return elementData.remove(elementData.size()-1);
}
public Object peek(){
return elementData.get(elementData.size()-1);
}
public boolean isEmpty(){
return elementData.size()==0;
}
public int size(){
return elementData.size();
}
}