Copyright won't help here. Extending it to allow the protection of concepts as well as literal implementation is what Oracle tried to do, and would've resulted in a few megacorps demanding licensing for core concepts that no one can really make quality, functional software without.
Of course, software patents are also stupid, even if the general intent of patents seems reasonable.
Martin Goetz, Who Received the First Software Patent, Dies at 93 (www.nytimes.com)
See also ESP Wiki’s entry on Martin Goetz.