If it ever had the slightest chance of being useful on Earth, it would not be called a "galactic algorithm". In this case that algorithm might be more than gala

If it ever had the slightest chance of being useful on Earth, it would not be called a "galactic algorithm". In this case that algorithm might be more than galactic: there isn't enough matter in the observable universe to build a conventional computer able to execute it. In fact a computer executing it would be so large that speed of light would be the main constraint limiting execution speed, not theoretical algorithmic complexity that ignores data locality.