package com.basic.datastructure;
import java.util.ArrayList;
public class Stack {
private ArrayList elementData = new ArrayList();
public void push(Object o) {
elementData.add(o);
}
public Object pop() {
Object o=elementData.get(elementData.size()-1);
elementData.remove(elementData.size()-1);
return o;
}
public Object peek() {
return elementData.get(elementData.size()-1);
}
public boolean isEmpty() {
return elementData.isEmpty();
}
public int size() {
return elementData.size();
}
}