One way to serialize a binary tree is to use preorder traversal. In this traversal, a non-null node’s value is recorded, while a null node is represented by a sentinel value such as '#'.

Given a string preorder of comma-separated values, determine whether it represents a valid preorder traversal serialization of a binary tree. Return true if it is valid, or false otherwise.

Note: It is guaranteed that each comma-separated value in the string will be either an integer or the character '#' representing a null pointer. You must not reconstruct the actual binary tree.

Constraints:

• $1 \leq$ preorder.length $\leq 10^4$

• preorder consists of integers in the range $[0, 100]$ and '#' separated by commas ','.

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.