On a related note, I've observed that some of the solutions to tough problems just perform matching on the input and print out hard-coded expected output. How utterly pointless.

I don't see the point in hackerrank-bashing though. The site's UI is nice and it has got a good selection of problems for brushing up coding interview skills. Also, I think that most companies that "hire based on hackerrank ratings" use it to feed their pipeline and do additional interviews on their own.