While solving leetcode problems I noticed that the binary tree problems are hard to test on my system because the Leetcode given input is an array and I had to build a tree and populate it by using method calls every time I solved one of those problems. So this is a simple utility function to help me build a tree really fast from an array input and test my problems. I suggest that you build your own, because to be fair I write pretty bad code usually. (I am much more comfortable with Typescript and C++ than I am with python.)

I hastily built it in like 10 mins, so pardon bros.

1. Copy the code to your file
2. Call the `BuildTree` class by passing an array of values in the constructor.
3. The returned object has a .root member variable, you can use that to test your leetcode functions Ez
4. _print_tree() method is a simple DFS to print out the tree itself to check if the values are correct.

[1,2,3,None,4,None,5]

Here 1 is root. 1 has two children, 2 and 3. 2 has two children None and 4, 3 has two children None and 5. So basically you write the array in a DFS manner. It starts from the root, then the children of root. Then children of first child and then children of second child and so on.

Feel free to contribute to make the code better and more usable.