Leetcode 1315. 祖父节点值为偶数的节点和（DAY 7）

原题题目

代码实现（首刷自解）

/*** Definition for a binary tree node.* struct TreeNode {* int val;* struct TreeNode *left;* struct TreeNode *right;* };*/#define MAX 10001int count(struct TreeNode* arr[],int* size)
{
    int sum = 0,i;if((*size)){
    for(i=0;i<(*size);i++){
    if(arr[i]->left){
    if(arr[i]->left->left) sum += arr[i]->left->left->val;if(arr[i]->left->right) sum += arr[i]->left->right->val;}if(arr[i]->right){
    if(arr[i]->right->left) sum += arr[i]->right->left->val;if(arr[i]->right->right) sum += arr[i]->right->right->val;}}}return sum;
}void visit(struct TreeNode* arr[],int *size,struct TreeNode* root)
{
    if(root){
    visit(arr,size,root->left);visit(arr,size,root->right);if(root->val % 2 == 0)arr[(*size)++] = root;}
}int sumEvenGrandparent(struct TreeNode* root){
    struct TreeNode* arr[MAX];int size = 0,sum = 0;visit(arr,&size,root);sum = count(arr,&size);return sum;
}