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.
参考资料：
https://leetcode.com/problems/leaf-similar-trees/
LeetCode All in One 题目讲解汇总(持续更新中...)
[LeetCode] Leaf-Similar Trees 叶结点相似的树
原文：https://www.cnblogs.com/grandyang/p/10771842.html