#965

Univalued Binary Tree

newbie · 250 · lc easy +18 · verified · 72.9% accepted · 1,978 likes · top 83%

Description

A binary tree is univalued if every node carries the same value. Given the root of a binary tree, return true if the tree is univalued and false otherwise.

Example 1:

Input: root = [1,1,1,1,1,null,1]

Output: true

Example 2:

Input: root = [2,2,2,5,2]

Output: false

Code

# 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 isUnivalTree(self, root: Optional[TreeNode]) -> bool:

# 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 isUnivalTree(self, root: Optional[TreeNode]) -> bool: