One of the most simply classification algorithm one can think of: just see whatever kind of point your new point seems to be closer to, and say it is also of that type! Then it is just a question of defining "close".
This is the first thing you have to know about supervised learning:
  • training is when you learn model parameters from input. This literally means learning the best value we can for a bunch of number input numbers of the model. This can easily be on the hundreds of thousands.
  • inference is when we take a trained model (i.e. with the parameters determined), and apply it to new inputs
Both of those already have hardware acceleration available as of the 2010s.