It's not either/or, you need to understand, not (just) memorize, the algorithms enough to see where they could be applied in or adapted to the domain in questio

It's not either/or, you need to understand, not (just) memorize, the algorithms enough to see where they could be applied in or adapted to the domain in question. Similarly, I could quip that nontrivial novel solutions require "actual" algorithms knowledge rather than exhaustive domain knowledge. Not surprisingly, in reality it's a bit of both.