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

Consider all the leaves of a binary tree.  From left to right order, the values of those leaves form a leaf value sequence.

For example, in the given tree above, the leaf value sequence is (6, 7, 4, 9, 8).

Two binary trees are considered leaf-similar if their leaf value sequence is the same.

Return true if and only if the two given trees with head nodes root1 and root2 are leaf-similar.
"""
# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def leafSimilar(self, root1: TreeNode, root2: TreeNode) -> bool:
        
        def findLeaves(root):
            t = [root]
            leaves = []
            
            while t:
                node = t.pop(0)
                if not node:
                    continue
                if not node.left and not node.right:
                    leaves.append(node.val)
                else:
                    t = [node.left] + [node.right] + t
            
            return leaves
        
        return findLeaves(root1) == findLeaves(root2)