Stack.java

package com.coding.basic;


public class Stack {
	
	private ArrayList list=new ArrayList();
	public void push(Object o)
	{
		list.add(o);
	}
	public Object pop()
	{
		if(isEmpty())
		{
			throw new IndexOutOfBoundsException();
		}
		return list.remove(list.size()-1);
	}
	public Object peak()
	{
		if(isEmpty())
		{
			throw new IndexOutOfBoundsException();
		}
		return list.get(list.size()-1);
	}
	
	public boolean isEmpty() {
		return list.size()==0;
	}
	
	public int size() {
		return list.size();
	}
}