https://leetcode-cn.com/problems/sum-of-nodes-with-even-valued-grandparent/
/*
* @Author: Goog Tech
* @Date: 2020-09-15 10:53:49
* @LastEditTime: 2020-09-15 10:54:29
* @Description: https://leetcode-cn.com/problems/sum-of-nodes-with-even-valued-grandparent/
* @FilePath: \leetcode-googtech\#1315. Sum of Nodes with Even-Valued Grandparent\Solution.java
* @WebSite: https://algorithm.show/
*/
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
// DFS : 深度优先遍历
public int sumEvenGrandparent(TreeNode root) {
return dfs(root, -1, -1);
}
private int dfs(TreeNode node, int parent, int grandparent) {
if(node == null) return 0;
int result = 0;
if(grandparent % 2 == 0) result += node.val;
result += dfs(node.left, node.val, parent);
result += dfs(node.right, node.val, parent);
return result;
}
}
'''
Author: Goog Tech
Date: 2020-09-15 10:53:53
LastEditTime: 2020-09-15 10:54:21
Description: https://leetcode-cn.com/problems/sum-of-nodes-with-even-valued-grandparent/
FilePath: \leetcode-googtech\#1315. Sum of Nodes with Even-Valued Grandparent\Solution.py
WebSite: https://algorithm.show/
'''
# Definition for a binary tree node.
# class TreeNode(object):
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution(object):
# DFS : 深度优先遍历
def sumEvenGrandparent(self, root):
"""
:type root: TreeNode
:rtype: int
"""
def dfs(node, parent, grandparent):
if not node: return 0
result = 0
if grandparent % 2 == 0: result += node.val
result += dfs(node.left, node.val, parent)
result += dfs(node.right, node.val, parent)
return result
return dfs(root, -1, -1)