>>I used to work at a company where some guys spent literally weeks inventing a fast way to do a dot product over huge vectors. Very nice that you bought up th

>>I used to work at a company where some guys spent literally weeks inventing a fast way to do a dot product over huge vectors. Very nice that you bought up this point. This is exactly what I was trying to point out. If a team of full time working people took weeks to arrive at a working solution, despite a massive body of open knowledge available as a reference to prior solutions, there is absolutely no way a candidate can give even arrive at a decent direction to the solution in under 45 minutes in a interview situation. No one is saying algorithms are not useful. But there is a very big difference between knowing an algorithm and inventing an algorithm. Testing the former is no indication of the latter, as illustrated by your own example.