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872. 叶子相似的树

请考虑一棵二叉树上所有的叶子,这些叶子的值按从左到右的顺序排列形成一个 叶值序列

举个例子,如上图所示,给定一棵叶值序列为 (6, 7, 4, 9, 8) 的树。

如果有两棵二叉树的叶值序列是相同,那么我们就认为它们是 叶相似 的。

如果给定的两个根结点分别为 root1root2 的树是叶相似的,则返回 true;否则返回 false

示例 1:

输入:root1 = [3,5,1,6,2,9,8,null,null,7,4], root2 = [3,5,1,6,7,4,2,null,null,null,null,null,null,9,8]
输出:true

示例 2:

输入:root1 = [1], root2 = [1]
输出:true

示例 3:

输入:root1 = [1], root2 = [2]
输出:false

示例 4:

输入:root1 = [1,2], root2 = [2,2]
输出:true

示例 5:

输入:root1 = [1,2,3], root2 = [1,3,2]
输出:false

提示:

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def leafSimilar(self, root1: TreeNode, root2: TreeNode) -> bool:
        self.leaves = []
        self.inOrder1(root1)
        return self.inOrder2(root2) and self.leaves == []

    def inOrder1(self,root):
        if not root:
            return
        self.inOrder1(root.left)
        if not root.left and not root.right:
            self.leaves.append(root.val)
        self.inOrder1(root.right)

    def inOrder2(self,root):
        if not root:
            return True
        
        left = self.inOrder2(root.left)
        
        if not root.left and not root.right:
            try:
                t = self.leaves.pop(0)
            except:
                return False

            if root.val == t:
                return True
            else:
                return False
        
        right = self.inOrder2(root.right)

        if left and right:
            return True
        else:
            return False

树 简单 每日一题

中序遍历第一棵树,然后比较第二棵树的叶节点即可

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