[vzidex]

> I'm not concerned If someone happens to know some esoteric trick that they could Google search (Unless of course you're applying for a position at a company that manufactures very low level devices like microcontrollers or embedded systems and questions like this are _actually relevant_).

The "XOR trick" actually nearly sank me on an interview once, I'm assuming because the interviewer shared your opinion. One of the questions they asked me to solve was the "n - 1 numbers in a list" question the article talks about - I promptly came up with the XOR solution because I have more background in low-level work than the high-level finance role I was interviewing for. Turns out, they had never seen it before, didn't really understand how/why it worked, and they took a lot of convincing to accept it as correct.

I think I only still got the job was by then proceeding to also solve the problem the "normal" way.