# Serialize and Deserialize Binary Tree

{% embed url="<https://leetcode.com/problems/serialize-and-deserialize-binary-tree>" %}

### Problem

> 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://support.leetcode.com/hc/en-us/articles/360011883654-What-does-1-null-2-3-mean-in-binary-tree-representation-). You do not necessarily need to follow this format, so please be creative and come up with different approaches yourself.
>
> &#x20;
>
> **Example 1:**
>
> ![](https://assets.leetcode.com/uploads/2020/09/15/serdeser.jpg)
>
> <pre><code>Input: root = [1,2,3,null,null,4,5]
> <strong>Output: [1,2,3,null,null,4,5]
> </strong></code></pre>
>
> **Example 2:**
>
> <pre><code>Input: root = []
> <strong>Output: []
> </strong></code></pre>

### Pseudocode

```
- order of output is breath first
    - push nodes into queue and serialize values
    - remove any null values from the end of array
    - stringify array 

- parse input as into array
    - takes first three vals, as root, left, right
    - if values of left and right child exist
        - push them back into queue for their child nodes to be added if available
```

### Solution

```javascript
var serialize = function (root) {
  let output = [];
  let queue = root ? [root] : [];

  while (queue.length) {
    let node = queue.shift();

    if (node) {
      output.push(node.val);

      queue.push(node.left || null);
      queue.push(node.right || null);
    } else {
      output.push(null);
    }
  }

  while (output[output.length - 1] === null) {
    output.pop();
  }

  return JSON.stringify(output);
};

var deserialize = function (data) {
  const arr = JSON.parse(data);

  if (!arr.length) return null;

  const root = new TreeNode(arr.shift());
  const queue = [root];

  while (queue.length) {
    let node = queue.shift(),
      val;

    node.left = (val = arr.shift()) || val === 0 ? new TreeNode(val) : null;
    node.right = (val = arr.shift()) || val === 0 ? new TreeNode(val) : null;

    if (node.left) queue.push(node.left);
    if (node.right) queue.push(node.right);
  }

  return root;
};
```

### Time and Space Complexity

#### Time

* What did the code do
* Total -

#### Space

* What did the code do
* Total -


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://grind75-notes.gitbook.io/notes/week-8/serialize-and-deserialize-binary-tree.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.