872. Leaf-Similar Trees

https://leetcode.com/problems/leaf-similar-trees

Python

DFS

class Solution:
    def leafSimilar(self, root1: Optional[TreeNode], root2: Optional[TreeNode]) -> bool:
        def dfs(node):
            if not node:
                return []

            if not node.left and not node.right:
                return [node.val]

            return dfs(node.left) + dfs(node.right)

        return dfs(root1) == dfs(root2)

Rust

DFS

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


impl Solution {
    pub fn leaf_similar(root1: Option<Rc<RefCell<TreeNode>>>, root2: Option<Rc<RefCell<TreeNode>>>) -> bool {
        fn dfs(node: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
            match node {
                None => Vec::new(),
                Some(node) => {
                    let node = node.borrow();
                    if node.left.is_none() && node.right.is_none() {
                        return vec![node.val];
                    }
                    let mut leaves = Vec::new();
                    leaves.extend(dfs(node.left.clone()));
                    leaves.extend(dfs(node.right.clone()));
                    leaves
                }
            }
        }
        dfs(root1) == dfs(root2)
    }
}