#给牛客的问题反馈和建议# j编译错误:您提交的代码无法完成编译Main.java:10: error: cannot find symbolprivate Stack data = new Stack();^symbol: class Stacklocation: class MyStackMain.java:11: error: cannot find symbolprivate Stack minStack = new Stack();^symbol: class Stacklocation: class MyStack4 errors这是全部的代码public class Main{ public static void main(String[] args){ MyStack myStack = new MyStack(); myStack.push(1); System.out.println(myStack.pop()); }}class MyStack{ private Stack data = new Stack(); private Stack minStack = new Stack(); public void push(Integer n){ data.push(n); } public Integer pop(){ return data.pop(); }}