There are plenty of issues with this tool, and I'd like to make some clarifications.
First off, the idea of a tool calculating the Big O complexity of a set of code just from text parsing is, for the most part, infeasible. In this implementation I was able to dumb it down to work with basic for-loops for most C-based languages, with the intent being that CS101 students could use the tool to get a basic understanding of Big O Notation.
However, after some thought, this tool alone could be harmful in grasping the true understanding of determining code complexity. Big O is not determined by for-loops alone. I do not want to make that misconception. Recursion algorithms, while loops, and a variety of algorithm implementations can affect the complexity of a set of code.
If you are new to programming trying to grasp Big-O, please checkout the link to my YouTube video below. It will give you a better understanding of determining Big-O complexity than using this tool alone.
I hope that this tool is still somewhat helpful in the long run, but due to the infinite complexity of determining code complexity through text parsing I will not be making any more updates to this tool, outside of minor bugs of what it is already able to determine: basic for loops.