I then tried a Python version, using the same workflow as with the C++. I backed off on the clever for the testing because I am not as sure about using multidimensional arrays in C++ and Python as I am in Perl. When you only code in a language about once every 15 years, you begin to forget the finer points.
Anyway. the code follows. I don't believe I'm doing a particularly stupid thing with my Perl here, but it's hard to ID particularly stupid things in languages sometimes. Here's the code, now with your USDA requirement of Node.js.