use std::cell::RefCell;
use std::rc::Rc;
impl Solution {
    pub fn is_same_tree(
        p: Option<Rc<RefCell<TreeNode>>>,
        q: Option<Rc<RefCell<TreeNode>>>,
    ) -> bool {
        match (p, q) {
            (None, None) => true,
            (Some(p), Some(q)) => {
                let p = p.borrow();
                let q = q.borrow();
                p.val == q.val
                    && Self::is_same_tree(p.left.clone(), q.left.clone())
                    && Self::is_same_tree(p.right.clone(), q.right.clone())
            }
            _ => false,
        }
    }
}