leetcode

0 class Solution {

1 public:

2 TreeNode *createBinaryTree(const vector<vector<int>> &descriptions) {

3 vector<bool> child(100001, false);

4 TreeNode *um[100001] = {0};

5

6 for (const auto &desc : descriptions) {

7 if (!um[desc[0]]) um[desc[0]] = new TreeNode(desc[0]);

8 if (!um[desc[1]]) um[desc[1]] = new TreeNode(desc[1]);

9 (desc[2] ? um[desc[0]]->left : um[desc[0]]->right) = um[desc[1]];

10 child[desc[1]] = true;

11 }

12

13 for (const auto &desc : descriptions) {

14 if (!child[desc[0]]) return um[desc[0]];

15 }

16

17 return nullptr;

18 }

19 };