He posts c code and says that it computes the inverse square root, but the code he posted is undefined c, so while it could compute the inverse square root of it's input it could also do a long list of other stuff.
One of the many reasons you should stay away from real world languages when talking about algorithms unless you are an expert in the language.
One of the many reasons you should stay away from real world languages when talking about algorithms unless you are an expert in the language.