[Miltnoid]

Yeah, considering it was an open question for 12 years, I'd be pretty surprised if you solved it immediately after hearing the solution. If you were provided hints by the interviewer and got to it with some directions, I most would believe it more.

What's more likely, somebody figured the solution out to a problem that previously took over a decade in under an hour and then felt the need to brag about it to strangers on the internet; or somebody lied online to feel better about themselves. People are certainly more likely to assume the latter.

[tom_]

Or perhaps people in the late 2010s are just better placed to answer this sort of question easily than people were in the late 1960s.

[mark-r]

I don't remember when I ran into this, but it was certainly earlier than the 2010's. Perhaps 1980's or '90's.

Certainly the Internet has made it more likely that you've run into it and heard the solution.

[mark-r]

I didn't know the history, I had no idea it was an open question for 12 years!

As I said, it was a very long time ago when I heard of the problem. I don't think it was in an interview, but I honestly don't remember the circumstances. I do remember being quite proud of myself, so I guess there's truly an element of bragging in my statement. Doesn't mean I lied though.

[mark-r]

It appears the tortoise-and-hare solution was found by Floyd in 1967. That means the problem was first proposed in 1955? I'd love to learn more about it, do you have a source for that?