leetcode

0 class Solution {

1 public:

2 Node *connect(Node *root) {

3 if (!root) return {};

4

5 queue<Node *> q;

6 q.push(root);

7 for (int lvl = 0; !q.empty(); lvl++) {

8 Node *prev = nullptr;

9 for (int t = q.size(); t > 0; t--) {

10 Node *root = q.front();

11 q.pop();

12 root->next = prev;

13 prev = root;

14 if (root->right) q.push(root->right);

15 if (root->left) q.push(root->left);

16 }

17 }

18 return root;

19 }

20 };