包含min函数的栈

public class Solution {
    Stack<Integer> s1=new Stack();
    Stack<Integer> s2=new Stack();
    public void push(int node) {
        s1.push(node);
        if(s2.isEmpty() || s2.peek()>node){
        s2.push(node);
}else{
s2.push(s2.peek());
}

}
    
  public void pop() {
        s1.pop();
        s2.pop();
    }
     
    public int top() {
        return s1.peek();
    }
     
    public int min() {
        return s2.peek();
    }
}