1315. Sum of Nodes with Even-Valued Grandparent

Medium

30 Points

Tree

Depth-First Search

Breadth-First Search

Binary Tree

Given the root of a binary tree, return the sum of values of nodes with an even-valued grandparent. If there are no nodes with an even-valued grandparent, return 0. A grandparent of a node is the parent of its parent if it exists.

Examples

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

Constraints

The number of nodes in the tree is in the range [1, 104].
1 <= Node.val <= 100