Col 5 is all about the Science and Art of Testing (rules and where, when and how to apply the rules).
-Define expected output
-Cover all cases
-C/C++ Compile-time assertions:
-When the algorithm is part of a big program, use scaffolding/automated testing/line-by-line debugger
-When the algorithm is stand-alone, print statements might be faster
-Be wary of bugs in different environments, experiment with them frequently to gain insights for fixing bugs