ArrayList implemented through Array

stack.java

import java.io.*;
public class Stack
{
   Node[] stack;
   
   public Stack(){
    stack = new Node[0];
   }
   
   public void pop(){
     if(stack.length != 0){
        Node[] newStack = new Node[stack.length-1];
        for(int i=1; i<newStack.length; i++){
            newStack[i-1] = stack[i];
        }
     }
   }
   
   public void push(Node n){
    Node[] newStack = new Node[stack.length+1];
    newStack[0] = n;
    for(int i=1; i<newStack.length; i++){
            newStack[i] = stack[i-1];
    }
   }
}