I have decided to take another crack at these problems for fun. As I am mostly writing C++ now the solutions moving forward will be done in modern C++ 17, and I will backport the CMakeLists.txt for all of the C solutions to be able to compile and run them. PHP solutions will just be manually run as they always have been.

Learning php, don't look at the code if you do not want spoilers! I am also slowly working through each problem and implementing a C version ;-)