package com.ecust.Util;
import org.xukai.common.ArrayList;
import java.util.EmptyStackException;
public class Stack {
private ArrayList elementData = new ArrayList();
public void push(Object o){
elementData.add(o);
}
public Object pop(){
if (isEmpty()) {
throw new EmptyStackException();
}
return elementData.remove(elementData.size()-1);
}
public Object peek(){
if (isEmpty()) {
throw new EmptyStackException();
}
return elementData.get(elementData.size()-1);
}
public boolean isEmpty(){
return elementData.size() == 0;
}
public int size(){
return elementData.size();
}
public void display() {
elementData.display();
}
}