IMHO it doesn't fit at all with the other things. You can implement In-Place Mergesort or one of its variants by studying Wikipedia. Or you can just look up a nice implementation from the OPs site and port it to your favorite language. That said, this argmin/argmax thing does absolutely not fit.
It's just ONE example, and if it's really the most interesting thing HN has to say on this (it was the top comment when I responded) then it's truly a sad state of affairs. Those btw are as much tutorials as they are "nice implementations", there are lots of things pointed out in the comments that you won't easily find on Wikipedia.
IMHO it doesn't fit at all with the other things. You can implement In-Place Mergesort or one of its variants by studying Wikipedia. Or you can just look up a nice implementation from the OPs site and port it to your favorite language. That said, this argmin/argmax thing does absolutely not fit.