> For the complete documentation index, see [llms.txt](https://junnie.gitbook.io/nine-chapter/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://junnie.gitbook.io/nine-chapter/2.binary-tree/297.-serialize-and-deserialize-binary-tree-h.md).

# 297. Serialize and Deserialize Binary Tree (H)

https\://leetcode.com/problems/serialize-and-deserialize-binary-tree/

Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.

Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure.

**Clarification:** The input/output format is the same as [how LeetCode serializes a binary tree](https://leetcode.com/faq/#binary-tree). You do not necessarily need to follow this format, so please be creative and come up with different approaches yourself.

 

**Example 1:**

![](https://assets.leetcode.com/uploads/2020/09/15/serdeser.jpg)

```
Input: root = [1,2,3,null,null,4,5]
Output: [1,2,3,null,null,4,5]
```

**Example 2:**

```
Input: root = []
Output: []
```

**Example 3:**

```
Input: root = [1]
Output: [1]
```

**Example 4:**

```
Input: root = [1,2]
Output: [1,2]
```

 

**Constraints:**

* The number of nodes in the tree is in the range `[0, 104]`.
* `-1000 <= Node.val <= 1000`

### Solution:

1. DFS 建树，DFS拆树（前序，后序。 中序因为不知道ROOT节点在数组当中的确切位置所以不行。）
2. BFS建树，BFS拆树。

<https://mp.weixin.qq.com/s/DVX2A1ha4xSecEXLxW_UsA>

<https://www.jiuzhang.com/problem/serialize-and-deserialize-binary-tree/>