LeetCode 1123 Lowest Common Ancestor of Deepest Leaves

Problem Statement

use std::rc::Rc;
use std::cell::RefCell;
use std::cmp::max;

impl Solution {
    pub fn compute_depth(node : Option<&Rc<RefCell<TreeNode>>>) -> u32 {
        if let Some(n) = node {
            return 1 + max(Solution::compute_depth(n.borrow().left.as_ref()),
                           Solution::compute_depth(n.borrow().right.as_ref()));
        } else {
            return 0;
        }
    }

    pub fn lca_deepest_leaves(root: Option<Rc<RefCell<TreeNode>>>) -> Option<Rc<RefCell<TreeNode>>> {
        if let Some(node) = root.clone() {
            let (l, r) = (Solution::compute_depth(node.borrow().left.as_ref()),
                          Solution::compute_depth(node.borrow().right.as_ref()));
            if l == r {
                return Some(node);
            } else if l < r {
                return Solution::lca_deepest_leaves(node.borrow().right.clone());
            } else {
                return Solution::lca_deepest_leaves(node.borrow().left.clone());
            }
        } else {
            return None;
        }
    }
}