  InterviewBit Academy is now Scaler Academy! # Serialize Binary Tree

Problem Description

Given the root node of a Binary Tree denoted by A. You have to Serialize the given Binary Tree in the described format.

Serialize means encode it into a integer array denoting the Level Order Traversal of the given Binary Tree.

NOTE:

• In the array, the NULL/None child is denoted by -1.
• For more clarification check the Example Input.

• Problem Constraints

1 <= number of nodes <= 105

Input Format

Only argument is a A denoting the root node of a Binary Tree.

Output Format

Return an integer array denoting the Level Order Traversal of the given Binary Tree.

Example Input

Input 1:

```           1
/   \
2     3
/ \
4   5
```

Input 2:

```            1
/   \
2     3
/ \ .   \
4   5 .   6
```

Example Output

Output 1:

` [1, 2, 3, 4, 5, -1, -1, -1, -1, -1, -1]`

Output 2:

` [1, 2, 3, 4, 5, -1, 6, -1, -1, -1, -1, -1, -1]`

Example Explanation

Explanation 1:

``` The Level Order Traversal of the given tree will be [1, 2, 3, 4, 5 , -1, -1, -1, -1, -1, -1].
Since 3, 4 and 5 each has both NULL child we had represented that using -1.```

Explanation 2:

``` The Level Order Traversal of the given tree will be [1, 2, 3, 4, 5, -1, 6, -1, -1, -1, -1, -1, -1].
Since 3 has left child as NULL while 4 and 5 each has both NULL child.```

NOTE: You only need to implement the given function. Do not read input, instead use the arguments to the function. Do not print the output, instead return values as specified. Still have a doubt? Checkout Sample Codes for more details. 