LeetCode 1315. 祖父节点为偶数的节点和
原题链接
中等
作者:
大明湖的鱼
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2021-01-31 22:36:43
,
所有人可见
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阅读 278
给根节点添加虚拟的父节点和祖父节点,递归时把当前节点的父节点更新为当前节点左右孩子的祖先节点
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
int sumEvenGrandparent(TreeNode* root) {
return sumEvenGrandparent(root,-1,-1);
}
int sumEvenGrandparent(TreeNode* root, int parent, int grandparent){
if(root == NULL) return 0;
int res = 0;
if(grandparent%2 == 0) res+=root->val;
res += sumEvenGrandparent(root->left,root->val,parent);
res += sumEvenGrandparent(root->right,root->val,parent);
return res;
}
};