| [117. Populating Next Right Pointers in Each Node II](https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/?show=1) | [117. 填充每个节点的下一个右侧节点指针 II](https://leetcode.cn/problems/populating-next-right-pointers-in-each-node-ii/?show=1) |
| [431. Encode N-ary Tree to Binary Tree](https://leetcode.com/problems/encode-n-ary-tree-to-binary-tree/?show=1)🔒 | [431. 将 N 叉树编码为二叉树](https://leetcode.cn/problems/encode-n-ary-tree-to-binary-tree/?show=1)🔒 |
| [200. Number of Islands](https://leetcode.com/problems/number-of-islands/?show=1) | [200. 岛屿数量](https://leetcode.cn/problems/number-of-islands/?show=1) |
| [947. Most Stones Removed with Same Row or Column](https://leetcode.com/problems/most-stones-removed-with-same-row-or-column/?show=1) | [947. 移除最多的同行或同列石头](https://leetcode.cn/problems/most-stones-removed-with-same-row-or-column/?show=1) |
