#1315

Sum of Nodes with Even-Valued Grandparent

pupil · 385 · lc medium +24 · verified · 85.9% accepted · 2,828 likes · top 97%

Description

Given the root of a binary tree, sum the values of all nodes whose grandparent (the parent of their parent) has an even value. Return 0 if no such grandparent exists anywhere in the tree.

Example 1:

Input: root = [6,7,8,2,7,1,3,9,null,1,4,null,null,null,5]

Output: 18

Explanation: The red nodes are the nodes with even-value grandparent while the blue nodes are the even-value grandparents.

Example 2:

Input: root = [1]

Output: 0

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 sumEvenGrandparent(self, root: Optional[TreeNode]) -> int:

# 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 sumEvenGrandparent(self, root: Optional[TreeNode]) -> int: