LeetCode 872. Leaf-Similar Trees

Problem Statement

// Definition for a binary tree node.
// #[derive(Debug, PartialEq, Eq)]
// pub struct TreeNode {
//   pub val: i32,
//   pub left: Option<Rc<RefCell<TreeNode>>>,
//   pub right: Option<Rc<RefCell<TreeNode>>>,
// }
// 
// impl TreeNode {
//   #[inline]
//   pub fn new(val: i32) -> Self {
//     TreeNode {
//       val,
//       left: None,
//       right: None
//     }
//   }
// }
use std::rc::Rc;
use std::cell::RefCell;
impl Solution {
    fn dfs(root: Option<Rc<RefCell<TreeNode>>>, v: &mut Vec<i32>) {
        if let Some(node) = root {
            if !node.borrow().left.is_none() {
                Self::dfs(node.borrow().left.clone(), v);
            }
            if node.borrow().left.is_none() && node.borrow().right.is_none() {
                v.push(node.borrow().val);
            }
            if !node.borrow().right.is_none() {
                Self::dfs(node.borrow().right.clone(), v);
            }
        }
    }
    pub fn leaf_similar(root1: Option<Rc<RefCell<TreeNode>>>, root2: Option<Rc<RefCell<TreeNode>>>) -> bool {
        let (mut v1, mut v2) = (vec![], vec![]);
        Self::dfs(root1, &mut v1);
        Self::dfs(root2, &mut v2);
        return v1 == v2;
    }
}